Installing cement backerboard is one of the more popular choices for a shower wall substrate. Cement backerboards include Hardiebacker, Durock, Fiberboard, wonderboard, and similar products. These materials bridge the gap between expense and effectiveness. When installed properly they will give you many, many years of durable shower construction.
The advantage of cement backerboards is that, while not waterproof, they are dimensionally stable when wet. That just means that when they get wet they do not swell up. Any swelling behind tile is a bad thing. It will lead to cracking grout, tile, and all sorts of bad things.
Waterproofing your studs
To install the backerboard you must have a vapor barrier between it and the wooden wall studs. While the backerboard will not swell when wet, your wall studs will. You must prevent any moisture from reaching them. The preferred material for a vapor barrier would be 4 mil or thicker plastic sheeting which can be purchased at places like Home Depot or any hardware store. You can also use tar paper or roofing paper, the thick black paper used under shingles. Although I personally do not use that, it is an acceptable barrier.
Starting with your bare wall studs on your shower walls simply take your plastic sheeting and staple it to the wall studs completely covering the entire surface which will be inside your shower. You can also use silicone instead of staples to adhere it to the studs. Make sure you overlap all the edges. Just hang it all up there like you’re hanging wallpaper. You want it covering the framing enough that if you were to spray the walls with a hose the wall studs and framing would not get wet.
At the bottom of the barrier you will want it to overlap on the shower side of the tub or shower base. That is you want it so that any water that runs down the plastic sheeting will roll off into the tub rather than behind the tub. Overlap the lip of the tub or base and silicone the back of the barrier to keep it in place.
Installing the backerboard
Now for the backerboard. Lay out your backerboards for the best fit on the walls. They can go up vertically or horizontally, it makes no difference. With a regular tub surround with a five foot back wall it is usually easier to use two horizontal sheets along the back wall and one vertical on each of the sides. (This assumes 3 X 5 foot backerboard sheets.)
All backerboards are cut by scoring and snapping. You do not need a saw for them. While there are special scoring tools specifically for this you can easily do it with a regular utility knife. While all these backerboards are essentially identical in their effectiveness as a substrate, some are more easily cut. Durock, in my opinion, is the most difficult. I personally prefer hardiebacker or fiberboard. Make sure you check the website for whichever you choose for specific instructions.
To fasten the backerboard to the framing you have a couple of choices. A lot of professionals simply use galvanized roofing nails. While this is perfectly acceptable, I prefer screws over nails when possible. Hardi makes specific screws for their backerboard which can also be used for all backerboards. These are manufactured with ribs beneath the head of the screw which help it cut into the backerboard and countersink so the head is flush. If your local big box or hardware store carries them, they will be in the tile section. You can also use just about any type of corrosion resistant screw. Anything that can be used for an outside deck can be used for your backerboard.
Fasten your backerboard to your shower framing with a screw or nail about every 8 – 12 inches. I would also suggest using a straight-edge along your wall while doing this so that you can shim out any areas where the wall studs may not be straight. The flatter your backerboard is installed, the easier your tile installation will be. Take your time, the beer isn’t going anywhere.
Allow for movement!
You do not want to butt the backerboards against one another. You need to leave a small gap at every change of plane. That includes corners, walls to ceilings, and walls to tubs or floors. There needs to be room for expansion and contraction.
Wood moves – always. It’s just a fact of life. The secret to dealing with the movement is to ensure the movement will not interfere with the tile. Leaving this small gap will allow for movement of the sheets enough so that they do not force against one another and push out. While the backerboard itself is very stable, you are still attaching it to wood.
If you have a tub or shower base you will also want to stop the backerboard about 1/8 inch above the lip. You do not want to run the board over the edge of the lip because it will cause the backerboard to bow out and your wall will not be flat. It will also allow the tub or shower base to move a bit – it’s attached to the wooden studs as well. Tubs also move when they are filled with water. You need to allow for that movement.
I usually leave about a 1/16 to 1/8 inch gap between the sheets of backerboard. This allows for thinset to lock into the entire thickness of your backerboard when you tape and mud your seams. We’ll cover that part in a minute.
Don’t allow for movement! (Confused yet?)
If your shower framing is such that you cannot place the edges of all the backerboards directly over a stud you will need to add more studs. You may do this with regular 2 X 4’s screwed to the present framing vertically or horizontally as needed. You must make sure that every edge of the backerboard is supported so if the wall is pushed or leaned on in that spot it does not move. You want solid walls.
Final step
The last thing you must do is mud and tape your seams. Similar to regular drywall all of your in-plane joints must be taped. To do this you just use regular thinset and alkali-resistant fiberglass mesh tape. You can find the tape in the tile section – it’s similar to regular fiberglass drywall tape, but it specifically manufactured to be alkali resistant. Make sure it is alkali-resistant because your thinset contains alkali which will gradually erode regular tape thus defeating the purpose.
There are two ways to address the corners. The industry standard, and the way you should do it, is to tape and mud the corner joint as well. Most backerboard manufacturers recommend this, as do the handbook standards. I only do that about half the time – I’m a rebel like that. 
*The other half of the time I only tape and mud the in-plane joints – the gaps in the same wall, not the corners. With the corners I fill the gap with silicone. I do this to allow the different planes of the walls to move in different directions, which they will do whether you like it or not. Allowing this movement in the substrate compensates for excess stress in certain applications. This is something that I do, it is not industry standard and you will likely not find anyone else recommending doing this. So when you get the conflicting information about this – that’s why. 
Fill all the gaps in your seams with thinset (you left gaps there, right?) then embed the tape into it. Then go over the tape with more thinset to smooth everything out. This will lock everything together and give you a continuous, solid substrate for your tile. That’s what you’re looking for.
When properly installed cement backerboards will create a rock solid, extremely durable substrate for your tile installation. Taking time and care to solidify what is behind or beneath your tile is the only way to guarantee a lasting installation. Your tile is only as durable as what it is installed upon.
As always if you have any questions at all please feel free to leave a comment.
Need More Information?
I now have manuals describing the complete process for you from bare wall studs all the way up to a completely waterproof shower substrate for your tile. If you are tiling your walls and floor you can find that one here: Waterproof shower floor and wall manual.
If you have a tub or pre-formed shower base and are only tiling the walls you can find that one here: Waterproof shower walls manual.
Love your site.
Situation: Home owner, 100% remodeling bathroom. Down to the studs. Pretty far along. Kerdi board in shower/bath alcove on wall and ceiling area. Installing 12” x 24” porcelain.
Problem/question: once I completed sealing the kerdi board seams with their kerdi band and thinset, then sealing those areas with RedGuard, I’ve rechecked my ‘flatness’ of the walls. I’ve now raised the seams such that from seam to seam there is a 2/16 – 3/16 inch trough between the seams. Basically means there is a dip that occurs over a 3 foot range. Should I be concerned with this? Or should it be easy enough to add extra thinset even it out? Thank you for your time.
Hey Kevin,
Provided you are using a 3/16″ x 3/16″ trowel or larger you won’t even notice those humps. If you need to add more thinset to certain areas to get a flat installation that’s easy enough to do while you are installing the tile.
Hi Roger,
I see you recommended to silicon where tiles meet old drywall outside the shower. Can you enlarge on this thought because I have seen different recommendations. I was planning to thinset and tape over the join between drywall and cement board (which are flush), then add a border tile at the join and paint over the thinset on the drywall side up to the tile. would you instead leave the gap open, or silicon the gap, then tape and thinset over it? I’m confused.
Thanks – Colin.
Hey Colin,
Nope – you have the procedure correct. When I said to silicone that what I meant was the finished tile installation where it ends at the drywall. Nothing to do with the gap between the drywall and cement board. Sorry – didn’t mean to confuse you. You have it all right.
Great – thanks again for all the help. I’m about to start the actual tiling so sure I’ll have more questions..
Hi Roger – have a couple of tricky questions…
first – when taping the intersection of two walls where they meet (or any non-flat joins), I understand that that gap shouldnt be filled with thinset – but how to avoid this? is it possible just to adhere thinset to the edges of the tape without getting any in the gap? seems like this would be tricky…
and my second question is.. I’m thinking of tiling the ceiling over my shower as well as the walls. I’m using subway tiles for the walls, and I wondered what you would do at the ceiling – carry on the pattern from the back wall, or the side walls? i.e. what orientation should the subway tiles be placed on the ceiling? obviously they are going to be mismatched to one or two of the side walls… I’m wondered if it would be better to use larger tiles on the ceiling instead to avoid this issue. what do you think?
thanks for all your help.. colin.
Hey Colin,
You can apply thinset only to the tape without getting it in the corner, you just have to be careful. You can also get some backer rod, which is flexible foam, and stuff that in the corner, that will keep thinset out of it. You can also use silicone in the corners, let it cure, then tape and mud them. Any of those options will allow for the movement you need.
Larger tiles look good on the ceiling, as do small square ones. I have matched both the side walls and the back wall (in different showers – I’m not THAT good
) and I think matching the side walls looks better – but it’s simply a personal choice. No real right or wrong way to do it. What I think looks the best is to have the subway tiles on the ceiling on point (en pointe – diagonally) that looks very cool. And you don’t need to line them up with anything.
OK – thanks. The angled tiles are a great idea. So right now I have drywall or greenboard (not sure which) on the ceiling, and I dont want to remove it (it would create a huge mess because of disintegrating insulation above) – can I just add new framing over this, put in a moisture barrier, then cover with cement board and tile? or alternatively, do the same but coat the cement board with redgard to seal it? I really dont want to take down the old lining..
cheers – colin
Hey Colin,
You can screw the backerboard right over the drywall into the ceiling joists and paint it with redgard. That’ll solve all your problems! (Well, your tiling problems anyway
)
Hi there!
We just tore out all the tile in our bathroom and shower/tub, and found regular drywall underneath the old shower tile. So we replaced that with durock cementboard screwed into metal studs. We live in a fire-rated condominium and all the studs are metal. We haven’t gone further in the shower yet and I was wondering if we need to worry about further waterproofing with metal studs since they wouldn’t absorb the water like wood does.
Also, we built a rectangular (1.5’W x 1’H) niche in the center of the largest tub wall. Our old tile went up 5′ from the tub and the new niche is centered at that height. We’ve been thinking about tiling higher up (6′ maybe?) or possibly to the ceiling with the mosaic tile we have, but didn’t know if that would look strange. You know, would it make the niche appear… off? I don’t like things looking half-assed – like yourself. I do assume we’ll need to waterproof the niche, regardless of the stud type. Correct? Oh! And some sites say you should just slightly (not visibly) angle the base so water will run out. True or false?
I know you’ll have some good advice. Thanks so much! I love your site :-)
Hi there back!
You do still need to waterproof that shower. Some studs will rust. I’m not certain about the specifications because no one around here uses metal studs except in commercial buildings – I don’t do commercial buildings. What I DO know that the TCNA standards for wall substrates over metal studs still requires either a moisture barrier behind it or a topical membrane over it. So it is required by standards, the exact reasoning is something I’m unclear on.
The niches set lower than the halfway height of the shower tile do tend to look a little goofy. I would probably double the height of that niche and put a shelf in the middle of it. That would look more balanced and give you more room for stuff. Any horizontal plane inside a shower, including the bottom of your niche or any shelves, do need to be angled out into the shower so water does not collect. It does not need to be a lot, I’ll usually just shim the back of a niche up about 1/16″. If you get too much of a slope your soap and rubber ducky will slide out of it. Just enough so it isn’t level or angled back toward the wall.
Thanks so much – that was such a quick response! Would we be able to get away with putting some liquid membrane over the screws only? I’d love to rant about the 80’s tile job they did with regular drywall, but it appears to have made it 30 years without a speck of rust on the studs. Rust-proof magic – that’d be the only thing that’s gone right with this bathroom…
I’m thinking after the many setbacks we’ve had that keeping the niche and tile height the same is the better strategy. For my own survival at least – I may not make it out alive if I ask for more modifications, haha. (After diagonal travertine floor tiling and a 30yr old super-glued shower valve debacle, I’m counting my blessings)
We’ll definitely waterproof the niche and angle the horizontal plane (pinky up). Thank you for the advice!
Hi Lisa,
Nope, cement backerboard is not waterproof, only water stable. Meaning it doesn’t fall apart when it gets wet. It still soaks in water like a driveway. So you’ll need to apply the waterproofing over the entire surface.
And never count out super glue, it works for lots of things. That’s all I’m sayin’.
Hi Roger:
I have a number of questions as a seasoned renovator, but a first-time tiler.
The bathroom itself is a fairly standard issue bungalow style bathroom (approximately 5’Wx 9’Dx 8’H). The tub is placed on the end of the bathroom opposite the door, with the long side of the tub being on the outside exterior wall (there is also a Vinyl/PVC window on this wall), and the two wing walls on the interior. We have already completed the plumbing, cement board and are getting ready to fibertape and thinset the joints. I believe it is here that my questions start:
From reading a number of forums, it was suggested rather the using furring strips on the stud faces (to build the studs out so that the cement board could be brought down right to the tub surface), that I could install the cement board directly to the wall studs, leaving a space of approximately 1/8″ above the tub lip. What I don’t recall reading however is an option to finish the bottom of the cement board against the tub. If I install the tile only to the edge of the cement board, you’ll still see the space, and more importantly it won’t be complete sealed from moisture. The other issue that I can see is that if I put the tile all the way down to the tub, I will have approximately 3/4″ of space that I need to fill with something (thinset, etc.) so that the bottom portion of the tile has something to adhere to. I have used silicone to fill this gap on all three sides so when the tub is in use, in theory the silicone should flex.
The other question I have is that on the long wall there is a window and when I installed the cement board within about a 1/2″ of the window casing (like doing drywall) so that I could have access to insulate around the window. Not that it’s too late, but should I have butted the cement board as close to the window jamb as possible to ensure that I can get the tiles to set properly? My biggest hurdle at this point is figuring out how to fill this gap so that I can overlap the tile onto the pvc jamb. The CBU is flush with the window jamb. My initial thought was that i could fill this with either thinset or deck mud, but all the reading that I’ve done thus far has still left me without an answer.
As for your advice on taping the vertical corners but not filling them – is the thought here that when setting the tile, that the thinset used to set the tile will fill any gap in the corners? I’m planning on using Redgard to waterproof the entire CBU area, and my only real concern is being able to waterproof around the window without having to go to something like Kerdi or bullnose tile, as I only have about 1″ of lip on the window jamb to work with.
I look forward to your response,
Jeff
Hey Jeff,
If you install your backer above the vertical flange you want to fill that gap with silicone (have you done that yet?). The idea being that when you install your redgard you paint it down onto the silicone. While it won’t necessarily adhere well to the silicone it will continue your waterproofing from the wall to the tub without gaps. You need to make sure the waterproofing is continuous. That takes care of the waterproofing aspect. For tile, just tile down over that gap to within 1/16″ of the horizontal tub arm. The tile does not need to be attached to anything there – really.
It should be only an inch or so and be waterproofed behind it, the tile can just hang there. Fill that 1/16″ gap with silicone (don’t forget weep holes). If you fill the tub with water, then install your silicone and let it cure, then drain the tub you will never have to worry about that silicone bead breaking loose – it’ll actually be compressed 90% of the time.
Around the window I would rip down 4″ pieces of backer (or however wide your wall cavity plus backer is) and glue them flush into the gap with the edge shower-side out. Essentially that will give you a continuous surface with the last 1/2″ before the window jamb being the side of that piece of backer rather than the face. Tape and mud around your window and install your redgard.
The idea in the corners is not to have any solid material between the two changes of plane. You want the back wall to be able to expand out (toward the wing walls) without busting tile. If there is thinset in there it will force the wing walls in the same direction and create lateral sheer. Not a lot, mind you, just micro-amounts at a time which, over time, can lead to problems. If that gap is left open there is room to expand in separate directions without placing stress on the adjacent walls. The thinset and tape simply give you a solid surface to continue your waterproofing around without gaps.
If that window idea won’t work let me know, I’m full of useless ideas.
Thanks Roger for the quickest reply ever. I have some clarifications on each of the three topics so, here goes.
I’ve installed the silicone in the gap between the cement board and the tub lip, but because that lip is approximately 3/4″ – 1″ high, and the CB is already a 1/2″ thick, when I install the tile (1/4″) I will have a space of that thickness (minus the thickness of the tub lip (maybe 1/8″) between the top of the tub and the bottom of the tile/redgard/cb. If I’m reading correctly, you’re saying when installing the tile onto the redgarded CB, to bring it down within 1/16″ish of the top of the tub? I had thought of that but because of my newbie-ness, my questions would be that a) Will the tile stay adhered if there is a void behind it? and b) If there is no substrate behind it, what is the recommended practice for grouting/caulking the gap between tiles? Would the grout adhere to porcelain/silicone/redgard?
It’s starting to make sense but as you mention in your ebook (which i read last night) I want to have this totally waterproof before even starting tile.
In the corners, before using tape and thinset, would having a bead of silicone in the two vertical edges where the wing walls meet the exterior wall do any harm? The silicone is by no means solid and (in my mind) would add an additional seal before taping and thinsetting the joints. Even with micro-movement as you describe, would even having silicone in there be enough to affect the final installation? I’m okay with overkill, but if it will be detrimental, then I can just tape and thinset, then redgard overtop.
Getting a good seal around the window is my biggest concern, and I did not think of using the edge of the CB at all. In retrospect (and for next time) I will butt it right up to the window jamb, but your suggestion will likely work. Because the window jamb is vinyl, is there a recommended glue or something similar that I can use to glue it either to the jamb or to the rough opening? There is already expandable foam and pink insulation in the window gap so I’ll have to see what fits depth-wise. I figure that I’ll tape off half the width of the jamb so that when applying the redgard it doesn’t get onto the rest of the jamb and will have to find a silicone that adheres to the PVC as well.
One other thing, a fellow here at work who just lent me a tile saw and and a mortar mixer mentioned that to get better adherence of the tiles, to soak them prior to cutting and/or installation. Is there an advantage to this? His thought was that the tile wouldn’t soak up as much moisture from the thinset. Seems logical, but I’d never heard of this before. At this point any advice is good advice.
Once again, thanks for your quick response and I look forward to your reply.
Regards,
Jeff
Hi again Roger:
I had a look at the window at lunchtime, and only on the top and bottom would there be enough space to slide a piece of backerboard in there so the edge would face out. Knowing that , if the space is less than a 1/2″ wide on the sides, would it be safe to pack the gap with thinset, tape between the wall and jamb and thinset overtop?
Jeff
Hey Jeff,
If you are using 12 x 12 tile and you have the bottom 1 inch hanging over that gap you only have 1/12″ of the entire tile not adhered to your substrate – it isn’t going anywhere. The grout actually adheres to the sides of the tile, not any substrate beneath it. That is true of walls as well as floors. While the grout will adhere to certain substrates, it is designed to work by sticking to the sides of the tile. As long as your redgard is continuous from your backerboard over the tub flange (and silicone installed there) your shower will be waterproof.
A bead of silicone in the corners will not hurt anything. You can do that if you want.
In the places around the window where there isn’t enough room for the 1/2″ backerboard you can simply thinset and tape over it. Once that cures install your redgard all the way to just over the pvc frame. (It will adhere to pvc windows)
Soaking tiles is old-school.
While some tiles still warrant it most newer tiles do not. The problem initiated with both the type of tiles and the chemical makeup of thinsets at the time, which were little more than sticky concrete. Regular clay-bodied ceramics (like quarry tiles) are very porous and suck in moisture. Installing these would cause the tile to prematurely suck moisture out of the thinset and weaken the bond since portland cures through hydration. That means that the longer water stays in your mix, the stronger your bond will be. With modified thinsets the polymers are inserted to retain water in the mix for a longer period of time – more water, stronger bond. Also the newer tiles are more dense and normally do not absorb moisture in that manner. If your tiles are red clay-bodied ceramic (if the back of the tile is reddish/brown) then soaking them before installation will help. If you have porcelain or a brown or white-bodied tile it won’t do much good.
Your buddy does know what he’s talking about but things have changed a lot. Glad I’m not the only knucklehead that knows about stuff like that.
Roger … in reading all the post about “overhanging” the tile a 1/2″ over the tub lip is assuming the wall tile is large tiles like a 12×12. If you are using a small tile like a 3×6 subway and the first row of tile above the tub needs cut lengthwise in order to get grout lines to align with the wall tiles that start at the floor, should there be a different thought process as to allowing the cement board to come down over the tub lip after furring out the wall studs. So many different situations and so many thoughts. I’m just saying.
All in all I have found your website to be a cornacopia of information. I’m just curious to know is when do you actually have time to set tile?
Hey Richard,
If the amount of space the tile will not be attached at the tub or basin is 1/4 or more of the height of the tile the backer should be furred out so it can run down over the flange of the base to within an 1/8″ of the horizontal arm of the tub.
I set tile all day, watch baseball / hockey and answer questions at night. I write the posts in stages whenever I have time (none). If you read one of the comments and there’s something in there like ‘Hey Ref! – you’re missing a hell of a game…’ – that’s why.
Roger … thanks for the reply, I thought what you just said was the correct path to take. I furred out the studs and let the cement board run down to roughly 1/8″ above the tub deck/horizontal arm.
Thanks again … obtw – when are you going to have a link so we can upload pics to show you how we did after you gave us valuable info.
Hey Richard,
I’m gonna stick a link in there sometime (in my spare time
) but until then you can always send me photos at Roger@FloorElf.com.
Hey Roger:
Once again, thanks for the quick reply. So, I’ve got the silicone everywhere it needs to be for now, and I’ve learned a little about grout. (I did not know that it adhered only to the sides of the tile.) This weekend will be all about trying to finish off that window so that I can mix up a batch of thinset and go over my seams. I also have tile edging to set into the thinset where the CB meets the drywall.
Instead of 12×12 tile, we have 6×6 tiles, so will the overhang of 1″ still apply? 5/6 of the tile will still be adhered to the CB, so hopefully that will not cause any issues.
Regarding the thinset, when we bought everything, the staff at Menards recommended Mapei Ultraflex 3 for bathroom installation, and I’m sure it will work fine, but after reading the instructions it says on the bag to not expose to water for 21 days. I’m sure I read that right, so does that mean that after all is said and done, we can’t even use the shower for 3 weeks? I’m all for letting things cure, but with the work that we’re putting in, it just seems like a letdown to have to look at it for that long. I was told that the grout will have to be sealed and there is a waiting period for that to cure as well. Any thoughts here?
I’d like to take this opportunity to thank you for the wealth of advice that you’ve offered not only to me, but to everyone that has questions or your site. So far it has definitely taken a little bit of the fear of tile out of the equation for me.
Regards,
Jeff
The 1″ still applies – it’ll be fine. I don’t normally use Mapei so I can only speculate as to the reasoning for that. I read the data sheets and all but I don’t see that anywhere. If it is on the bag I assume the issue they are attempting to prevent would be latex-leeching. UF III would be a HIGHLY modified mortar – which means it has a very high polymer content. Polymers require air and time to fully cure. Full cure time for any portland-based thinset is 28 days. Before that time the polymers (latex or latex-like) may leech and/or be washed out of the uncured bed if exposed to large amounts of water. Like I said, I can only speculate as to the reason. You may want to contact their customer service number and ask them – they should be able to give you specifics. That would be the only reason I could think of offhand.
Or, you could simply switch to Ultraflex II – that will work just fine and it’s about 1/2 the price.
If you use a good sealer (miracle sealants) you can seal the grout the next day. Really. Remember – people at Menard’s are attempting to sell you stuff. 
Hey Roger!
We’ve already got the UFIII from when we picked up the tile some time ago. We did get a couple quarts of sealant (GuardAll by TEC), so even if it’s possible to seal the grout the within a few days, there could be a possibility of maybe using it within a week? I’m okay with waiting too, I guess I just don’t want to take my time and then rush into using it before it’s ready. While on the topic of sealant, is there any harm in sealing the tiles and the grout all at the same time, or should both be done anyway?
Also, tomorrow being project day, do you know of a good adhesive that will bond the CB to the vinyl window?
Cheers,
Jeff
I don’t see any reason at all to not use a typical residential shower within a one week time period. You can seal the grout and tile at the same time. The only thing I know that would definitely adhere to the vinyl on the window would be epoxy. No real reason to stick the board to the vinyl, though. Just go right up to it, silicone any small space that’s left, and install your redgard.
Hi Roger:
Well the seams are taped and mudded, and the thinset was much easier to mix than I would have thought. the biggest trick was figuring out the proper ratio for only 8 lbs – enough to just do the seams, corners and around the window. So far so good…I’ll let it sit for a day or two then Redgard it up. One thing I thought of though is if we run out of thinset when setting the tiles (only have one 50lb bag), if I run to the local Home Building Centre, they have thinset but do not carry the same brand as we have. Is it best to have the same stuff or can I use another brand providing it’s the same polymer type?
Also, when setting the tiles, what do I do about the corners…do I run the tiles into the corners or leave a space and use silicone? You mention that grout will adhere to the sides of the tile, but because it’s a change of plane, I’m thinking that I wouldn’t want anything in the corners that could be affected by movement?
Slowly we’re getting there!!
Regards,
Jeff
It is always best to stick with the same thinset brand and type from start to finish. If you still have 42 lbs of thinset left that should be plenty to install whatever you need in that shower. With that typed – I have mixed different thinsets on jobs. You’ll never find a manufacturer that will tell you it’s all right, though. Imagine that.
You want silicone at all changes of plane and anywhere tile meets a dissimilar material – like the tub or the drywall outside the shower.
For the corners do I just want to tape them and spread thinset over the tape? Not like you would do a seam on a flat wall where you thinset, tape, then thinset again.
Hey Tyrel,
Absolutely correct! No thinset in that gap – only over the tape.
Good Day…..I have spent a ridiculous amount of internet time trying to simply decide if I should go CBU (ie Durock) or DensShield for my shower stall rebuild……I like the the idea of using a cement board but have 2 issues with it. 1-to waterproof the surface with Redgard would cost additional $180.00 (1 Gallon costs $90.00 at my local HD). 2- Confused as how to blend in untiled face of Durock with regular drywall. Denshield seemed like the way to go until it seemed like 50% of web sites I came across said to stay away from it.(to be fair, there is no indication that the people who dislike DensShield are legitimate tile contractors…) Is there a reason to prefer one over the other?I am mucho confused…..
Hey Kevin,
No real reason at all. Both products work correctly and very well provided they are correctly installed. The Denshield (I know, I always spell it incorrectly
) is much lighter to work with, cuts much easier and is much, much cleaner. You do need to silicone the seams and all the screw holes to waterproof it, but it works very well. And, you know, it’s cheaper. 
I still use denshield in certain applications.
Tip: If you go the denshield route it is much easier to put a dab of silicone in the spot you are going to place the screw and drive the screw right through the middle of it. Use coated screws and that’s all you’ll need to do to waterproof the screw holes. If you use the durock just tape and mud the seam at the drywall but use thinset in place of regular drywall mud. Once finished you can paint right over it.
Hi Roger,
I have a question about cement board in a shower. Since the screws put in to hold cement board up go through the moisture barrier, wouldnt this allow some moisture to penetrate into the walls? Or is the defect in the barrier created by the screw just too small to worry about? Love your site.
Thanks – Colin
Hey Colin,
The ‘pucker’ in the barrier created by the screw allows water to run down the wall and around the screws without entering the wall. Main water penetration into a wall cavity will come at areas where the water is allowed to run down the wall and into the cavity – not necessarily into the wall from front to back.
This is a great site….I have one question….Can you use caulk for the gaps in the cement board….I have heard this works as well as the thin set and tape?
Hi Jason,
Nope, not the same at all. The thinset and tape create a monolithic structure which will prevent the individual boards from moving separately.. Caulk is a flexible product – it’s not gonna do that.
Great site. I am building a shower and I have stud walls attached directly to concrete walls and I used Therma Sheet Foam Insulation in between the studs. I was planning to add 4 mil vapor barrier and then Hardiebacker boards. Considering that the Therma Sheet does not breath through am I creating potential for trapping moisture between the Therma Sheet and the 4 mil barrier? If so, what should I do? One idea I had was to not use the 4 mil barrier and simply run strips of rubber tape flashing over the studs, to protect the stud and seal with the two adjacents Therma Sheet Panels. That would kind of form a vapor barrier….maybe I need more beer…
Hey Mauro,
You won’t have any problems behind your barrier with moisture. That, by the way, was a good idea! And yes, you need more beer anyway.
AWESOME website. Starting the project tomorrow. Can I just remove the old tiles and then retile over the old board? I really don’t want to ripe out the old board and replace with new.
Hi Scott,
I dunno, I can’t see it from here.
It depends on what type of ‘old board’ you are talking about and whether or not the current installation is in good shape. You CAN, but do you really want the durability of your new tile installation to rely on someone else’s workmanship without knowing exactly how it was done? If the tile comes up easily, and if you have a solid, proper substrate, and if the backerboard (if it is backerboard) has thinset installed beneath it, and if … you get the point. It all depends on what shape that old stuff is in after you tear out the tile.
Thanks for the quick reply. It is the original tile from the original construction in 1976.
Great website! Thanks for all the info. One question. I’ve installed cement board in my tub, but didn’t put a waterproofing membrane behind it!! I’ve already taped the joints with thinset. Do I need to rip out the cement board and start over? Could I paint the cement board with a waterproofing “paint”? Please help.
Thanks, Rafi
Hey Rafi,
If by your ‘bathtub’ you mean the tub/shower combo then yes, you need waterproofing of some sort. The paint-on membranes such as redgard, hydroban and the like will work just fine. And it’ll be easier and quicker than starting over.
In the above case should the waterproofing paint be applied before or after the joints are tapped & mudded?
After they are taped and mudded.
OK … one last question before the big project gets started, what would be the best type of adhesive to use for attaching the ceramic tile after the backer board (cement type) has been painted with the waterproofing paint such as redgard or hydoban?
A good modified thinset sold in 50lb. bags that you mix with water. No premixed anything!
Thanks again … but one last thing that I thought of last night. In previous comments you stated that you tape corners but do not mud them. Am I to understand this as you apply some thin set mortar to the flat surfaces of the taped corners BUT DO NOT allow the two planes of mortar to be blended together?
HI Richard,
You don’t want to fill the gap between the two separate planes with mortar. That’s all I mean. With the flat seams you fill them with thinset, then tape them, then skim over them, with corners you skip the filling part.
Thanks for all the info, hopefully the tile job goes smooth!
Hello. Just trying to clear up some confusion on my part. If you leave a gap so the hardibacker can move, why then would you then fill up the crack with thinset? I understand why you would tape and put thinset on top of the backerboard so that the board will move from end to end the same and not just at one end and crack the tile from the stress. Help! I am ready to start my tile work soon. Thanks for all you great info!
You leave a gap in the boards on the same plane, fill them, and tape over them to create a monolithic structure for your wall. The gaps you leave in the corners are to allow movement, you still need to tape over them, but do not fill them.
Good info here, thanks! We are installing new tile in our shower We have removed all the old tile and are at the old backerboard. There is old mastic but still fairly level. Should we remove all the old mastic before we retile or will that make the walls not waterproof?
I’m sure you will say remove the mastic. What is the easiest way?
Hi Lora,
I dunno, it depends on how your shower was waterproofed. If there is still an intact barrier behind the old backerboard then it will remain waterproof whether you scrape the old mastic off or not – you should remove as much of that as you possibly can. Mastic does absolutely nothing in regards to waterproofing in your shower. It is dependent upon the barrier behind (which you should have) or the product over the top of your backerboard.
I wanted to know if it made a difference if i installed the backer board first before i poured the mud for the pan liner or vice versa. i see alot of youtube videos where the backer board is installed and then the mud bed is poured covering the bottom of the board. Is this correct or does it make a difference? Thanks
Hi Lisa,
It doesn’t make any difference at all. You can have your shower floor built over your existing substrate or over backerboard, either one works just fine.
Roger, I am preparing to build a shower pan using goof proof strips for the proper angles to the drain. I plan on using (Sandmix) for the pre slope and also for the layer on top of the liner. What mix should I use for the curb construction? I plan on making a form from 1/2″ plywood for the curb construction. Should I put a layer of felt on top of the pre slope layer and under the liner to prevent chafing? Also, exactly how much of a gap between the Durock cement board and the flooring is advised and should I put a bead of silicone between these two to prevent wicking? Thanks in advance. Your website seems to have a lot of great suggestions.
Hey Kevin,
The sandmix you speak of still needs to have sand added to it – but you knew that, right? The sand and topping mix is a 3 : 1 ratio of sand to portland cement. You need to add 25% – 50% more sand to it. For a 60lb. bag of mix I add 25lbs. of sand. For the curb you need to simply add powdered lime to the mix – 25% of the weight of the sand mix. You want the sand:portland:lime ratios to be 4:1:1. However, if you are simply making a form and filling it you can use the same ratio without the lime that you use for the deck mud and just make sure it’s packed down really, really well.
No need for a layer of felt on the preslope – those liners are a hell of a lot more durable than you may think. I like to keep the durock off the floor 1/8″ – 1/4″. No need to silicone that unless you want to – doesn’t hurt anything. They will not wick water in most residential showers, it’s more of a problem in commercial showers.
Roger,
I am doing my niche and there was not anything to screw cement board to so I used 3/4 plywood for back and will screw Hardi backerboard to it(shower was added to 2×6’s and there was a gap to outside then insulation). There will be a vapor barrier of plastic behind cement board over 3/4 ” plywood. I also needed to use plywood shims to square wall then again vapor over shims on one of walls( I am doing a shower stall with tile eventually.) Have already done this. Will this be okay?
I have taped and used mudd but I am waiting to see where grout line will end before completing niche. Thanks again
Dick
Yup, you’re fine with that. It would have been better to simply use strips of plywood to screw your backerboard to in the niche, that way you don’t have so much wood in direct contact with your vapor barrier, but it should be fine the way you’ve described it.
Thanks roger. I feel like ripping it out and putting strips of plywood but it took too much effort to screw in. Would have been much easier using strips. What was I thinking(I wasn’t)(had to fit into small area). Are the strips of 1/4 inch plywood to level wall behind the backerboard okay with the vapor over them?
Also, what is best way to put plastic barrier into niche before installing cement board?
Thank you for all assistance
Dick
Yes, the strips of ply will be fine with the vapor barrier. The barrier should be cut and folded the same way as kerdi when it is used as waterproofing. This post: http://floorelf.com/how-to-build-a-niche-for-your-shower-2 describes how to do that. You attach all the edges to the barrier on the wall with silicone rather than thinset.
Roger,
Getting ready to tile tomorrow. Will let you know how it goes when I get to niche. Thanks for all the great information. If you have not written a book on tiling you should. Great site.
Dick
Thanks for the informative site. You have made clear that tape with thin set should be used on the joint between the cement board panels, but what should be done with the joint between the cement board and the drywall? Any advice would be helpful.
Thanks!
Hey Richard,
Same thing, tape and thinset. Anything that isn’t covered by tile can be painted right over.
Nice site, tons of info. I wish I had found it earlier. So here’s the situation I’m in, I removed my fiberglass shower stall to replace it with a ceramic/porcelin pan and tile the walls (also built a nichce into the wall) I have done the hardie backer board thing with a 6 mil vapor barrier behind it. I have since found the Laticrete watertight floor and wall product. I want to make all the corners/seams waterproof, but don’t want to cover the entire walls (the whole double barrier sandwich thing). If I use the water proof stuff on the seams and corners only, what type of thinset will I need? Laticrete says use a latex thinset on top of their product. Will this be acceptable for the “non Laticreted” cement board? Thanks in advance. Oh yea, as you can probably tell, I’am a beer drinking novice trying to impress the wife. lol
Hey Jason,
Laticrete Watertight is a liquid membrane which is brushed or rolled onto your substrate. If you have a properly installed moisture barrier (6 mil plastic) there really is no reason to waterproof the seams. But if it helps you sleep at night – feel free.
Regular latex modified thinset will work fine over both the Watertight and regular bare cement board. You’ll never fully impress the wife – drink more beer.
Thanks for quick response, I was hoping you would say that (the drink more beer part) ,also the part about the watertight. Providing I don’t waterproof the seams, is latex thinset still the best way to go? I have almost gone friggin’ crazy with all the info out there about thinset etc.
The shower gets used about 8 times day on average. Thanks again
Hey Jason,
Yes, drink more beer … errr, I mean yes, latex modified thinset is still a better option. The latex polymers allow water to remain in the mix for a longer period of time, which makes the concrete cure more slowly, which makes it stronger.
And drink more beer. And stop taking so many damn showers – it diminishes the buzz.
Got It…….more beer, less showers. Thanks again for the professional advice, I’ll definately bookmark this site for future beer drinking questions…….I mean tiling questions.
Hi Roger,
I appreciate your prompt response. Now I have a problem with wall on shower valve side. The vent stack where the coupling is comes out 3/16 of an inch beyond wall. The prep work is most important and this is a predicament for me.
The other shower stall was fiberglass and due to cavity this was not an issue. Everything else is ready for hardiboard. (ran into this last night). I had furred out top 3/4 already on one stud and ran into this situation. Went out of my mind because I was ready to go..Do I need to tear out stack and bring inVery little space to do this. Thanks for advice
Dick
You can either tear out the stack and replace or move it, shim out your (entire) wall, or you can place a stud on each side of it, use 1/2″ backer to either side, then install a strip of 1/4″ backer where the stack sits. Any one of which should allow you to shim everything to an even plane.
Thank you for all your help..Best site for tiling
Hi Roger,
I mud and taped the backer board joints with ready mix joint cement and self adhesive fiberglass tape. Should I cover that with thinset or is this adequate for tile prep? Certainly don’t want to do elaborate tile work and find the foundation is inadequate!!! Thanks
Hi Sandra,
Is the ‘ready-mix’ joint cement regular drywall compound? If so that is the incorrect product to tape your backerboard joints. You want to use regular thinset (rather than joint compound) and alkali-resistant fiberglass mesh tape. If that’s what you used it should be removed and replaced with thinset – regular joint compound is water-soluble and won’t work in a shower.
The label says joint cement but follows with “do not add water”. The wording cement led me to believe it was the product in needed, but there is no reference to alkali and directions, “do not add water”. Sounds like I used the wrong product!?!?!?
Dunno – was it gray or white? If it’s white it’s the wrong stuff. If it’s gray I’ll need a link to the product to see what you have there.
Mmmm, it’s white sorry to say. Sounds like a redo. Any tips on that? AND so glad to know that now (before I end of on your slop page). Thanks so much Roger.
You’re welcome! On the plus side if you soak it down with water it should come off fairly easily.
Thanks again and love the work you’ve done! Appreciate all that you offer here.
Roger
Your website is very helpful – thank you!
I have a question about a 1920’s house I’m renovating. I’ve got existing ceramic tile mortar-bed installed to 55″ above the floor around the entire bathroom. I am adding a new tub with shower where the old cast iron tub was. Rather than tearing out the 2″ of tile / cement & metal mesh on the existing back wall of the new shower, I would like to tile over it. I plan to shim out the plaster wall above the tile w/ 1×2’s (to be flush w/ existing tile) & then cover it & the tile below w/ Hardibacker. Can I adhere the backer directly to the existing tile? What kind of adhesive should I use? Do I need a vapor barrier? Thanks for your insight!
Hi Heather,
You can tile over it. I don’t do that so my answers derive from limited experience but I would at least remove the tile to get to the mud (cement) behind it. You can then either install your tile directly to the existing mud or install hardi with thinset – although I honestly do not know how solid that would be. If you get to the mud behind the tile you can float out any areas that came out or aren’t flat. You do need some sort of waterproofing for the shower. A topical membrane like kerdi or redgard would be your best bet. There is no way of which I am aware that you can go over existing tile and have a membrane behind your substrate – you will need a topical membrane.
If you put the hardi over the existing tile you should at least insert some sort of mechanical fastener in several areas and not rely solely on the thinset to hold it there. Anchors and masonry screws perhaps.
Hi Roger – thanks for the advise on the tile over existing tile…I’m still working on that
Another question – I have an existing window on the back wall above the tub. I need to keep the wood frame b/c of the old pulley/weights system is accessed from there. I plan to put a solid vinyl roller blind over the frame & window, but want to make it as watertight as possible (I know this isn’t ideal). I’m using the HB 500 w/ Redgard around the tub. In your opinion should I cover the window frame with Redgard as well, then paint? Or just silicone the hell out of the area around the frame? Or both???
Also, the thinset I am using is TEC Superflex. Is that acceptable for both wall & floor tile? I have it left over from a backsplash installation…which was so much more simple than this project!
Thanks again. BTW I’m amazed at your patience explaining all this to all these rookie / wanna-be tile installers like me. THANKS!
Hey Heather,
Over a tub/shower you should be fine with just a good epoxy-based paint on the frame (properly sanded and prepped, of course) and yes, silicone the hell around the frame. You can redgard and paint it if you want but it’s a pain in the ass to paint over redgard. Superflex is good stuff and yes, you can use it for both the wall and floor tile.
As far as patience – well, I used to be a physicist (seriously), you guys are soooooooo much easier to be patient with than politicians.
Geez, got another question for ya…I’m concerned about the joint between the HB over existing tile & the HB over the shimmed out plaster wall I asked about earlier. Should I bridge that transition w/ 1 peice of HB or create a seam at the transition?
I would bridge that transition and tie it all in together in whatever fashion you can to create on large, monolithic wall. I’ve said I don’t know how solid the hardi is gonna be over the existing tile so whatever you can do to solidify the entire section as much as possible would be best. A seam would allow differential movement between the two substrates – that’s no good for your tile.
Any tips on scoring/cutting HB? I’m using a carbide blade to score, but can’t seem to get clean/straight line when snapping (particularly when I’m trying to take just 1/2″ off). Also, with that daunting disclosure on the HB product – am I installing the next asbestos?
Thanks!
Hey Greg,
Try scoring it with the carbide blade, then running a utility knife down the line, then alternate them about three or four times. Then when you go to snap it wiggle it back and forth rather than just pushing down to snap it. It also breaks cleaner sometimes when you pull it toward the cut rather than away from it for the snap.
No, it isn’t the next asbestos.
There are, however, a certain group of DIY’ers without common sense enough to wear a respirator or at least a dust mask when cutting through CEMENT board with a grinder or saw. Inhaling particulates in any form on a regular basis is never good – cutting cement board with power tools leads to a LOT of dust – it looks like your ass is on fire, I’m talking a lot! You don’t wanna inhale that stuff. These particular people can be found firmly planted on their ass approximately 17 hours a day watching, strangely enough, the DIY network.
Hi Roger,
I have a question about screws. I am attempting to hang 1/2″ wonderboard onto the studs around my tub with Rock-On countersinking screws but I can’t seem to get them flush. I have a strong enough screw gun but it strips the head. I can get them to the point where all that sticks out is the head (maybe 1/32″?). Is this sufficiently flush so that the thinset will be thick enough to mask that tiny bit or will my tiles look lipped?
Thanks
Hey Chris,
The minimum thickness of thinset beneath a tile installation is 3/32″. If your screws are only sticking out 1/32″ you should be fine. If you are getting lippage as you install your tile you need a bigger trowel.
A 1/4″ x 1/4″ square notched trowel will leave a 1/8″ layer of thinset beneath your tile with 100% coverage – you should be fine.
Hi… I was ripping out my old shower (and it leaked more than I ever imagined), and noticed that the 1*4 subfloor planks were a bit, shall we say, water-stained. Luckily, I have access to joists where I can drop in another subfloor. You mention that ply is a bad idea. Should I use more 1*4s and cover them with cement board? Or would ply subfloor below cement board be ok?
While we’re on the topic, is it ok to shim the cement board to level out the part of the floor where i can’t easily rip out the subfloor planks? Thanks.
Hey Rich,
Ply is a bad idea behind shower walls – it’s just fine for a subfloor (and standard). You can install cement board to level out any part of your floor – ‘shim’ it with thinset. All your cement board used as a subfloor needs to have thinset beneath it to eliminate voids and fully support your floor. So yes, you can shim it – with thinset.
Wow – your site is a revelation! how come none of the tile books mention weep holes? Thanks for the clarity..
I have a question though – I am slowly working through my tub to shower conversion. Having read your site I’m a little worried. I had to remove drywall from the shower compartment and behind it was a kind of fiberboard lining, which I also removed. To make up the thickness lost I replaced this fiberboard on the back wall with 3/4 inch plywood. Then I redgarded this whole surface as a vapor barrier. I’m planning to install 1/2 inch hardieboard over this surface, then marble tiles. But i realized that this design wont allow water to funnel to the weep holes above the tub (since there is no “funnel” at the base). Would it be ok to place a thin strip of polyethlene above the top of the tub, sealing it to the wall and tub surface with silicone, then redgard again over the join? My feeling is this would provide a route for water to get to the weep holes, while avoiding the problem of two vapor barriers (by filling the gap with sealant).
My second question is I though that maybe you implied in one thread that plywood should not be used behind cement board, but then in another thread you suggested that solution directly.. Please dont tell me I’ll have to rip down the plywood…
cheers – colin.
Hey Colin,
If you are using a topical membrane such as redgard you can use plywood behind the backer, if you are using only a vapor barrier you should not. You have a bit of both there. I have honestly never seen a situation such as yours so I really can’t say whether or not you’ll have a problem with it. Wondering why you didn’t simply use the redgard as was intended on the face of the backer??? How big is the gap between the tub flange and the redgarded plywood? I really wouldn’t trust a siliconed piece of poly just at the bottom of the wall there. You may be better off just covering the entire face of that board with poly and utilizing that as your main vapor barrier, call the redgard a safety net. Since the face of the ply is already redgarded it won’t hurt anything and you’ll not get enough vapor back there if to make a difference if you poly the entire shower.
With all that typed – the ideal solution is to take down the ply, fir out the wall to where you need it with just firring strips, and install the backer then redgard that. However, I realize no one lives in the ideal world so do whatever fits your budget.
Oh, and I’ve been accused of MANY things in my life – giving someone clarity has never been one of them.
(thanks!)
Thanks for the quick reply! I know, I would have done this differently if I had read some of your posts first. my main motivation was to make sure that a window frame was completely waterproofed.
However having thought about it more, I’m feeling better about this design, despite my apparent creativity here. There is no gap to very little gap (1-2 mm) between the ply and the tub flange – in fact the redgard filled the gap completely most of the way along. I think I could actually fill the minor remaining gaps with silicone alone and there would be no way for water to get back to the plywood, and it should run nicely down into the tub via the weep holes.
Just to clarify though – are you really saying that it would not be a problem to add poly over the whole wall? wouldn’t that result in two vapor barriers? I thought this was forbidden..
cheers again colin.
Allrighty then.
Make sure you get a full silicone bead in there to ensure it’s sealed. Also watch for cracks in that gap – redgard will shrink a bit as it cures.
Having two barriers directly against one another doesn’t hurt anything. The problems arise when you have a substrate trapped between them which may turn into mold food. That coupled with no way for moisture to dissipate leads to problems. Two barriers directly against one another is similar to a normal vapor barrier over faced insulation – done all the time.
OK thanks! I will add the extra barrier, clarity again! I have no problem with the extra safety factor…
I have another unrelated question though.. I did my tile shopping at the “tile shop” here in WI, and they make these plastic niche boxes for ready-made niches (one of which I have already integrated into the wall). They say you can tile direct to the plastic with thinset. However there is a lot of flex to this box when installed, especially on the back wall… have you ever seen these and any thoughts of their utility? I am thinking of installing backer first on this thing to stabilize it..
Hey Colin,
Do you know the particular brand of pre-made niche? There are several on the market. Some are designed to be used with epoxy setting material only – are you certain it states installation with thinset? Installing backer on it is gonna make it just as strong as installing one full piece of tile on it. I don’t use them, they are rarely the correct size to line up all my tile the way I want. I’m an ass like that.
The guys that do use them, though, usually like ’em so there’s nothing wrong with them, they work as they should. I could probably help more if I knew exactly which brand you have there. Or is it an actual ’tile shop’ brand? I’m unfamiliar with theirs if it is.
I’m a lot of help, huh?
Thanks for the answer last night. I also have purchased a niche – Noble Company’s niche – for a similar purpose. I assume I just use the same thinset that I’m using for the rest of the job? Thanks.
Hey Rich,
Yup, same thinset as the rest of the shower for that niche.
Tile shop didn’t say, but I think its a Tile Redi product. I think I will add the backerboard just to make certain the tiles don’t move. The plastic does seem pretty thin and deformable.
You must be sick of this line of questions by now, but I have one more – why is plywood behind a shower a no-no? is it because if water leaks into the ply it will expand? Seems to me that this would be true of any wood backer (including framing), drywall, etc though, and the only way to prevent it is effective waterproofing behind the cement board in any case.. or am I missing some key fact about plywood?
Thanks for all your comments, maybe you should make this a full time job!
Hey Colin,
Most tile-redi products require epoxy setting material to adhere anything to it – that includes backer. The epoxy is normally included with their products. I would go back and talk to whomever sold you that to see what’s going on with it.
When you have only framing you have 1 1/2″ strips of wood pressing against the back of your substrate. Normal humidity and temperature changes cause all wood to expand and contract. The open spaces between the studs leave room to compensate for this movement without pressing directly against your substrate. If you have a full layer of plywood against the entire back of the substrate it can only expand in one direction – against the back of your tile. Studs have two planes on which to expand – front to back and side to side. Full plywood sheets only expand in one plane – front to back (for the most part).
This is a full-time job – I just manage to fit it around my other full-time job.
I never get sick of helping people do something correctly.
OK, that makes sense. I am just going to add a lot of extra redgard and poly here to try and block any water getting to that ply. Thanks for all the help again Roger!