In my previous post about thinsets I explained what modified thinsets are and how they came about. That post actually started out as this post, I tend to get sidetracked by beer my dog.

Unmodified thinsets, in one form or another, have been around forever. With the expanded use of modified thinsets, the unmodified version had nearly gone by the wayside with everyone except us hard-headed setters who bought unmodified thinsets and added liquid admixes to them – to create modified thinsets. I no longer do this for my modified thinsets, but it was a hard habit to kick. :D

The reemergence (I know – doesn’t even look like a word) of unmodified thinsets came about in November of 2001. At an NTCA / Schluter workshop the statement was made that the preferred method of installation over ditra is the use of an unmodified thinset.

Mass confusion ensued.

This has continued to this day with even seasoned professionals questioning if unmodified should be used, and if so – why and which unmodified to use. This problem is compounded for do-it-yourselfers who don’t have nearly the understanding nor material and product access that we do. It’s difficult to find and purchase. If it helps, it’s sometimes difficult for us as well.

So let’s see if I can shed a little light on the subject and at least let you know which ones to look for and where. This list WILL be a bit biased. If you’ve read anything here you know I’m a Laticrete diehard. It is, and will continue to be, my preferred manufacturer for nearly every tile and stone setting material needed. That said typed, I do realize that other companies exist. :D

Just like modified thinsets, there are different levels or grades of unmodified thinsets. This is normally measured by the ratio or percentage of cement to sand in the mix. The higher the cement content, the better the thinset. More cement, more sticky, more stable.

It is also, in part, due to the type and percentage of whatever retention product is in the mix. For most thinsets (as far as I can tell – ancient guarded secret and all…) a powder called ‘hydrated lime’ is used. It is the same lime used by brick masons in order to retain water in the cement mix for a longer period of time, thus making the cured product stronger.

So that’s how unmodified thinsets are ‘grouped’ or graded – the ratio of those three items in the mix. Now that you know that, let’s group them in order according to how they are graded and perform. I’ll do this by manufacturer since most people only have one or two specific brands available.

Laticrete 317

Laticrete 317

Laticrete:

Laticrete 272 is considered the premium (best) – then Laticrete 317. There is negligible difference in these thinsets unless an admix is added to make them modified. For use as an unmodified I prefer the 317. Although they classify the 272 as their ‘premium’, they’re nearly identical.

The difference in these two thinsets: “There is more portland cement in LATICRETE 272 and the sand in the

Laticrete 272

Laticrete 272

LATICRETE 272 is slightly finer so it is a little bit creamier.” (Thanks to Anita at Laticrete for this clarification) The 272 contains 25-35% portland while the 317 contains 20-30% portland.

On the consumer side Laticrete products often have a different name – you may be familiar with Laticrete MegaBond. That is nearly identical to the 317. I use 317 for almost all of my unmodified thinset needs.

Mapei kerabond

Mapei kerabond

Mapei:

Kerabond: This is considered Mapei’s premium unmodified thinset. It works very well for any Schluter product

 

 

 

 

 

Mapei Keraset

Mapei Keraset

Keraset: This is Mapei’s mid-range unmodified. It’s not ideal but it works if it’s the only available. Give it extra time to fully cure! If you use Keraset be sure to wait a FULL 24 hours, at least, before the next step.

 

 

 

 

 

Mapei keraflor

Mapei keraflor

Keraflor: The ‘economy’ level unmodified from Mapei. I would not recommend using it for any shower applications or any regularly used flooring surface over ditra. Best to find one of the other two.

 

 

 

 

 

Custom Uncoupling Mat Mortar

Custom Uncoupling Mat Mortar

Custom:

Uncoupling Mat Mortar: This is Custom’s premium unmodified mortar made specifically for Custom’s spiderweb mat and other ditra-like products. It is difficult to find and has limited availability. If you can get your hands on it, use it.

Masterblend: Currently Custom’s only readily available (to my knowledge) unmodified thinset. It is available at most Home Depots. It’s a good sack of powder if you have a flood and need a makeshift levy. That’s it. Any reputable tile contractor will tell you not to use this for anything – ever. I’m one of them. The only really good thing I can say about it – It is an unmodified thinset.*

Custom masterblend

Custom masterblend

*This is by no means any type of intentional slander or slam against Custom building products! They make some great products. Masterblend, however, is not one of them in my opinion. And that’s all this is – my personal opinion. I do not consider this a viable product with which to install tile or stone over Schluter products.

 

 

Tec SturdiSet

Tec SturdiSet

Tec:

Sturdi-Set: Tec’s premium unmodified. A good unmodified thinset for nearly anything requiring one.

 

 

 

 

Tec full set plus

Tec full set plus

Full-Set Plus: Tec’s other unmodified. Comparable to a mid-range unmodified. It’ll work in a pinch if needed, but ensure full cure time before the next installation stage.

 

 

DitraSet

DitraSet

Bostik (Hydroment):

Ditra-Set: This is the best product with which to set anything over kerdi or ditra – it was specifically manufactured for that purpose. The availability is extremely limited, however. Most professionals don’t have ready access to it, let alone regular homeowners. So just plan on not finding this.

If you are lucky enough to find it you’ll feel ecstatic, like the luckiest person alive! If you don’t find it you’ll just think ‘Well, FloorElf told me I wouldn’t find it…’. See – win-win for me. Yay.

So in the groups above it breaks down like this:

Best:

Bostik Ditra-Set

Laticrete 317 (Laticrete MegaBond)

Laticrete 272

Mapei KeraBond

Tec Sturdi-Set

Custom Uncoupling Mat Mortar

Works if limited options exist:

Mapei KeraSet

Tec Full-Set Plus

It’s last call – find something:

Mapei KeraFlor

Go home alone and hold onto your wallet:

Custom Masterblend

So there you have it. The most commonly available unmodified thinsets and where they rate on the scale of quality. As I stated, this list is biased. The list above is the order in which I would use them if given the choice. Regardless of the order under each heading (Best, Works, etc.) this is how they are rated by their respective manufacturers.

Do not be surprised if you cannot find one of the quality products easily. They are not commonly stocked by regular big box stores except for the Laticrete Megabond. The best place to look for any of them would be at a tile supply shop. If, however, you are limited to normal big box stores, you can find some of the common products there.

Lowes will either stock Laticrete or Mapei. Home Depot will only (currently) carry Custom products. Menards normally stocks Mapei. Beyond those three, I have no idea what you may have around you.

You can always check the respective company’s website to find the nearest supplier. Since you will be looking for one of the more uncommon products keep in mind that just because you have a supplier near you does not mean you’ll find that particular product there. It’s always best to call the customer service line and ask them directly where you can buy the product you want.

One last thing – before anyone asks: adding more portland cement to a particular product may or may not make it better. Adding more cement to masterblend, for instance, will not make it comparable to kerabond. It doesn’t work like that. These thinsets, as all tile installation products, are put together in specific ratios in order to accomplish what the company wants. It may work, and it may not work. Unless you personally know someone in the chemistry department of the manufacturing plant there is no accurate way to tell.

ANSI Specifications

All thinsets, as well as any tile installation product, will have a specific ANSI (American National Standards Institute) number on the bag. This determines what type of product it is and what ANSI standard it meets. The number for unmodified thinset is A118.1. The ‘.1’ at the end determines the unmodified version. If you find a thinset you are curious about, and it is not on this list, look for that number. If it has A118.1 AND more numbers after that (with no mention of admix) then it is a MODIFIED thinset.

For instance, if it says on the bag that the product meets ANSI standards A118.1, A118.4 and A188.11 then it is a modified thinset. All modified thinsets meet the criteria set forth for unmodified thinsets as well, that’s why the A118.1 is on there.

ALSO! (I know it’s a pain, I live it) Most bags of UNmodified thinset have the A118.1 number as well as the A118.4, possibly A118.11 also  If it does it will plainly state that it only meets the last two standards (for modified) when mixed with the appropriate admix. Masterblend states that it meets all three – with the addition of admix (liquid latex). Don’t let this confuse you. They cannot legally misstate the ANSI numbers.

I hope this helps clear up a little bit of confusion about these products and helps you determine which would be appropriate or best for your project. As always, if you have any questions please don’t hesitate to ask them below. I answer them all. I’m just super cool like that. 8)

 

{ 695 comments… add one }

Leave a Comment

  • Mike

    Can I use the non modified mortar to install porcelain over durock.

    • Roger

      Hi Mike,

      Yes you can. As long as it isn’t customblend. :D

  • Afterburner

    Love the site, keep up the good work!
    I am using Duroc on the walls of my shower with Red guard on the seams and probably all of the surface, and using unmodified there with 12″ porcelain.
    Using mosaic 2″ tile over my dry set shower pan. All using 1/4 X 1/4 trowel.
    In the rest of the bathroom unmodified under Schluter ditra-heat on concrete floor and on top with 12″ X 24 porcelain using 1/4 X 3/8 Trowel All Tile will be back buttered.
    Would you change anything with this plan?

    • Roger

      Hi Afterburner,

      I would use modified thinset over redgard, and definitely redgard the entire wall.

  • Ben

    The best in my area that I could find is the Tec Full-Set. Using this between the Kerdi Board and my 6×24″ vertical Marazzi Montagna Dapple Gray tile. Planning on using a 1×4 x 3/8″ trowel. Do I need to mix the thinset with any admix or just water suffice? Trowel size good?

    • Roger

      Hi Ben,

      Mix with nothing but water, and your trowel size is fine.

  • Mark

    Roger,
    Thank you for all your knowledge. I plan to use ditra over my OSB subfloor using mapei ultra flex 2 (modified) per the ditra directions. I will be laying 16″ porcelain on top of the ditra and was told to buy the mapei kerabond t (unmodified). Will the kerabond t bond properly to the 16″ porecelain and make a great connection to the ditra? I keep reading that porcelain tile should use modified. Thanks for helping a paranoid DIYer that likes to have all his ducks in a row!!

    • Roger

      Hi Mark,

      Yes, the kerabond t will work very wall for tile to ditra. Doesn’t matter if it’s porcelain or not – really. :D

      • Mark

        Thanks so much! I’m also wondering your thoughts on an even transition from tile to white oak hardwood. I bought a piece of L shaped metal schluter that matches the dark brown of my hardwood floors. I have seen houses that butt the metal transition right up to the hardwood. My concern with doing that is how does the wood have any room for expansion?

        In your expert opinion, how would you transition from hardwood to tile so that is completely seemeless and not have to use a t-type transition piece? Thanks so much for your insight!!

        • Roger

          With an ‘l’ shaped transition piece I leave a 1/16″ gap between the metal and wood and silicone that gap.

          • Mark

            Thanks!!

  • CJP

    Great info! I was a hard-headed setter who bought unmodified thinsets and added liquid admixes to Laticrete materials from 1980. (pics are of one of my remodels). With the new materials available, I’m not sure what I can get by with on my subflooring support anymore. I always used 1+” for tile. 3/4″ T&G plywood with at LEAST 1/4″ subfloor, nailed 4″ on center. I’m building my last house to “age in place” in. So a custom handicap roll in shower(no threshold at all). My did slope to the drain by planing down the yellow pine 2×10 floor joists in the shower area. Then used 3/4 T&G Advantech pulled down with the flathead Timberloks & liquid nails. I’m trying to stay as low as possible. (The whole bathroom floor framing is dropped 1/4″ to hopefully end up closer to the laminate flooring height at door). Never had this problem with tiling to meet up with 3/4″ oak flooring. I have a roll of schluter ditra(found at Habitat for Humanity store, so no instructions ) to put down, thinking it will conform to the slope & waterproof into the rest of the bathroom. Would the stiffer Advantech & Ditra be enough support for 12″ porcelain tile?

    • Roger

      Hi CJP,

      Yes, you’ll be just fine with that. You do need to use modified to bond it to the advantec, but it’ll work fine for your application.

  • Anna

    Roger,

    First, thank you for all of your articles as they’ve answered a lot of my questions. :-)

    I’m a DIYer and I called myself following the directions on the bag of non-modified mortar to use between my underpayment (not subfloor) and hardiebacker. My problem is I’ve mixed with too much water. No where near peanut butter. :-(

    Am I doomed? Have to start over?

    Anna

    • Anna

      Darn auto corrector. I meant underlayment not underpayment.

    • Roger

      Hi Anna,

      No, you’re not doomed. Your fine if you’re using it under your hardi.

      • Anna

        Thanks for your reply Roger. In a panic I bought another $5 bag to mix more in. I wish I waited for your reply. Now I have a half bucket of non-modified mortar leftover.

        My porcelain tiles call for another kind of thinset so…how to get rid of all of this mortar? I had envisioned keeping the bucket. 😕

        • Roger

          Dump it out in a trash bag, then when it cures take a rubber mallet to the outside of the bucket to pop off the cured thinset.

          • Anna

            Great idea! You’re awesome! Thx

  • Wes

    Roger,

    I’m building a shower using a Durock EPS material pre-formed shower tray. Durock specifically states to use unmodified thinset in all aspects of installation, including adhering the tray to the plywood subfloor. However, everywhere I have looked online says that unmodified will not properly bond with plywood and to use modified instead. Since the thinset is the only bonding material used to install the tray (no screws are used), I want to make sure I’m using the correct type of thinset. Do I need to add a layer of cement board on top of the plywood (using modified) and then adhere the tray to the cement board using unmodified? Any words of wisdom would be greatly appreciated.

    PS I found a tile place near me (pretty easily I may add) that sells Bostik Ditra-Set. Anybody in the D.C. area looking for it, call Morris Tile.

    • Roger

      Hi Wes,

      If you go directly to the plywood I would use modified. If you put cement board over it you can use unmodified. You don’t need to use modified thinset to place cement board over the ply, you can use unmodified for that too. The thinset is not there to bond, it’s there to fill voids, the screws hold it in place.

  • Stephanie

    This seems to be a floor site, but you are extremely knowledgeable, and I can not find the answer to my question anywhere! I am placing brick veneer on the wall behind a wood burning stove. Because of the contraction of temperature changes, I want to use a modified thinset. However, I am concerned that the added latex polymers will not handle the heat. I can also use type s mortar. They are just 1/2 inch veneers, but I don’t want them sliding down the wall as I put them up. What are your thoughts? The more I read, the more confused I get! Thanks!

    • Roger

      Hi Stephanie,

      The heat is not going to affect the polymers in powdered modified thinset at all.

  • Dusty

    Hello Roger,
    I’m installing wood plank porcelain on ditra. I’m using unmodified thinset like they recommend my problem is they say use large tile thinset and I can’t find any large tile unmodified thinset. What would your recommendations be on this?

    • Roger

      Hi Dusty,

      Regular unmodified thinset will work just fine.

      • Dusty

        Awesome thanks for the quick response. Would u recommend a bigger notch than 1/4 x 1/4 which is what I normally use. I have always back buttered my tiles so was going to do that also.

        • Roger

          I would use at least a 3/8″ trowel for that. 1/4″ isn’t nearly large enough.

          • Dusty

            Thank u

      • Jake

        Hey Roger, if any of your readers are in the Seattle area Master Wholesale sells the Bostik Ditra-Set for about $23! As well as may more of your top un-modified choices.

        Jake

        • Roger

          Thanks Jake!

  • Kara Brophy

    Hello,
    I am about to install kerdi around my hardibacker tub walls and the drywall guys mudded over the seams and the mud extends into the shower by about 5 inches. Should I sand it all off as best I can or will a latex or oil primer do the trick? I am using kerabond T for my thinset.

    Also, would like to extend tile all the way to ceiling and am not 100% sure if that’s hardibacker all the way to ceiling. Tile shop told me ti use mastic above the shower head, but that’s contrary to everything I’ve read online.

    Very grateful for your advice!

    • Roger

      Hi Kara,

      Sand it off as much as you can. If you can get to where you can see the seam you’ll be fine. As long as it’s above the shower head it doesn’t need to be hardi, but don’t use mastic (you already knew that). :D

      • Kara Brophy

        Thank you so much for the quick response – much appreciated!
        Is primer a good idea up top if I can’t sand off a lot of that? Bummer when you can’t trust the advice of the local reputable tile shop :/ That’s why I love your site!

        • Roger

          Yes, primer will be fine if needed, but you don’t want to rely on that below the shower head. It is water-soluable, so when water gets to it it’s going to release from the wall. Anything attached to it will do the same.

          • Kara Brophy

            Roger, Roger. Thanks so much!

  • Rich

    Roger great info
    I’m tiling over a concrete foot there was vinyl tile before,it was removed all that’s left is some glue . The vinyl floor is 60 yrs old . It’s probably asbestos glue that was used .there is very little glue left . Should I used Laticrete 317 with 333 additive ? If so should it be all additive mix or can I use half water ? Thanks

    • Roger

      Hi Rich,

      Yes you should. Just the admix, no water.

  • John M

    Roger

    I am a DIY working on replacing a tub with a walkin shower and am using the Schluter shower kit (base, curb, Kerdi membrane) plus a heated tile floor. I have unmodified thin-set mortar for applying the Kerdi membrane to the wall and shower base however was told by the retailer to use a polymer modified thin-set to bond the tiles to the wall and floor.

    I am very confused (ok, easily accomplished) as your previous post about thin-set mortar types described the reasons for modifying the mortar was to increase curing time which in turn increases bonding strength. I am using 6 inch by 36 porcelain tiles so am concerned over binding strength. The confusion comes from the recommendation to use an unmodified thin-set mortar over the Schluter Ditra membrane…. does this compromise bonding strength ?

    Also does this increase the curing time (the Schluter manual reads something like up to 60 days could be possible) and references latex leaching…. whatever that is.

    Any guidance greatly appreciated !!

    John

    • Roger

      Hi John,

      No, using unmodified mortar does not compromise bond strength. The fact that the membrane is waterproof and you are placing a large tile over it ensures that water in the mix does not prematurely dissipate and the full bond strength is reached. Using modified will increase cure time.

      Everyone makes it confusing. Use unmodified to install your tile, you will have full bond strength as well as maintaining your schluter warranty.

      • John M

        Roger

        Thank you so much for fast response – I now know which type (unmodified) of mortar to use in the shower and need not be concerned over reduced bonding strength !

        Should I use modified mortar for the floor tiles over the heating cable…. I am using the Schluter sheets with the raised honeycombs that hold the cable (sorry I cannot seem to find the correct product name) or would modified be a better choice for this area. I am using a 6 inch by 36 inch porcelain tile ?

        Thanks again – your site is very helpful to DIYers !

        John

        • Roger

          If you are using ditra-heat then you need to use unmodified mortar to bond the tile to the mat over the wires.

          • John M

            Roger

            Thank you for the quick and informative reply.

            I now understand which mortar to be using – unmodified over the Kerdi and Ditra-heat. The store that sold me the Schluter shower & floor heat kits, tile and mortar exchanged the modified mortar no problem. This time he recommended Laticrete 317 which after checking your site I accepted as I see you rate it quite highly. This is a bit a pain moving 50 pound bags of mortar to and from the site by snowmobile (on a seasonal road) but this is all part of the experience.

            I have another question if I may impose….. I am installing 6 inch by 36 inch (3/8 inch thick) porcelain tiles on the floor and walls in the shower area and am wondering what size of trowel you would recommend. I was thinking of using a square notched 1/4 by 3/8 inch to apply the mortar to the wall & floor and buttering the tile with the Schluter Ditra trowel.(square notched 11/64 inch by 11/64 inch). Does this sound like it will work ok ?

            Thanks,

            John

            • Roger

              Hi John,

              Yes, those trowels will work just fine.

              • John M

                Roger

                Thanks – very much appreciate the quick and informative answers !!
                I think I am now set up for a bit with your assistance.

                All the Best,

                John

  • Jason

    Hi Roger,
    I have Ditra heat TB mat and wire in, and now getting ready to put down large format tile (9″x43″ Porcelain tile). I have a bunch of laticrete 317 from setting the Ditra left over, but I wondered if TEC 338 uncoupling would be a better choice for the large format given it says it is suited for medium bed application. Thoughts?

    • Jason

      Another quick thought is to use the 317 for a skim coat and fill the waffles and let it cure. Then come back with the TEC for the actual tile setting, mortar bed and back buttering…..

      • Roger

        Hi Jason,

        That would likely be the best option.

        • Jason

          Thanks! I just wasn’t sure if I would run in to issues with 317 and TEC getting a good bond or not. Given they are both an unmodified, I wouldn’t expect an issue for adhesion between the two. Would you?

          • Roger

            Absolutely none.

  • Dan

    I appreciate the very helpful information you are providing and I’m scouring the Reno/Carson City area for the thinsets you recommend (with not much luck yet). I am confused however by a comment you made in your posting about modified thinsets–you said you always use modified thinset, even when Ditra calls for unmodified. Your comments on the unmodified thinsets in this article lead me to believe that you have considerable experience with them. I’m not particularly concerned by warranty issues–I just want to use the best product I can find–the last thing I want is a tile braking loose. Please clarify that for me–I confuse easily. Thanks, Dan

    • Roger

      Hi Dan,

      Schluter requires that non-modified mortar be used in order to retain the warranty. I have extensive experience with all sorts of thinset. I use what I want depending on the tile I am installing. Not too sure what your question is?

    • Clint

      Aurora tile and marble
      D&L tile

      One of the two have ditra set can’t remember which

  • Steve

    Too everyone that would like to get the ditra set it is available on amazon but very expensive. I did find it for 14.37 at a tile supply store so I feel very lucky.

    • Maureen

      And Morris Tile carries Therabond. Beautiful to work with. No other tile stores in my area carry anything specific to decoupling membrane.

      • Maureen

        Sorry. Kerabond!

  • Thom

    Sorry, wrong email on my last question.
    Can I put silica sand in unmodified thin set to make it unmodified medium bed?

  • Thom

    I need to build up unmodified thin set over schluter to maybe 5/8″ but can,t find medium bed unmodified. Can I put silica sand in my unmodified thin set to make it not slump? Will this let me build up the unmodified to 5/8″ thick?
    Sometimes these schluter products are irritating.

    • Roger

      Hi Thom,

      Why do you need to build it up that much??? I think it would be stable enough to be durable, but I’m not confident enough to tell you to go ahead and do it, it’ll be fine. KnowWhatIMean? :D If you tell me why you need to do that I can likely give you an alternative with which I would be confident.

  • shannon

    My understanding (and we have done this on many occasions for installs) is that unmodified mortar is used for the lack of air between a plastic membrane of any sort (ditra or otherwise) and a porcelain tile. Please correct me if wrong.

    Thank you,
    Shannon

    • Roger

      Hi Shannon,

      That’s part of it. The biggest positive aspect of unmodified is that it will cure at a regular rate, like clockwork, whether it’s sandwiched between two impervious layers or not. Nearly everything will cure, eventually, but unmodified is reliably efficient with zero guesswork.

  • Joshua DeMarcinco

    Hello and thanks for the specs and information….quick question..laid some mesh heated floor mats, skimmed them down with a modified thinset. We have several bags of unmodified ditra-set left over, would it be ok to use to set 18×18 tile over the cured modified or would you suggest sticky with a modified for the application?..thank you!

    • Roger

      Hi Joshua,

      I would STRONGLY suggest using a modified thinset for that application. You’re going to have a lot of expansion and contraction in that floor.

  • Mark

    Will Tec 369 polymer modified mortar , full contact mortar work for putting Vitra down over plywood?
    Will Tec 338 uncoupling membrane dry set white work for setting tile over Vitra ?
    This is Menards offering. They no longer carry maipes products
    Thankyou

    • Roger

      Hi Mark,

      Yes to both.

  • Maureen

    I have Ditra down. I understand that I should not use self-leveling compound over it. But if I mix the unmodified thinset very thin and apply it over the Ditra, can I essentially get a self-leveling effect? I don’t know that I need extra help with leveling. But I’d like to have the reassurance that I’ve done all I can. Thanks!

    • Roger

      Hi Maureen,

      No you can not. You will get a self-leveling effect, but once it cures and all that water dissipates you’ll simply have an uneven mess. If you want an slc effect you need to use slc.

      • Maureen

        Thanks. I have spot filled my low spots with kerabond over the ditra. I’m guessing it’s too late for SLC. I think I’m okay, though. It’s pretty good. I’m guessing that 12*24 tiles are too risky, all things considered. After all I’ve learned in the past two weeks of studying on the net, I wonder if any diy-er should tackle large format tiles as a first tiling project. BTW – When people talk about cracking, is this mostly in the grouting?

        • Roger

          Yes, it is about the grout 95% of the time.

  • Marcelle

    Can I trim my 6″ tall schluter shower curb down? is there a code on it?

    Also, do I need to use unmodified thinset to attach my stone tiles to my Kerri membrain. What about porcelain?

    • Roger

      Hi Marcelle,

      Yes, you can trim it down to whatever you need. Most codes (check your local if you’re worried) require a minimum of two inches above your finished inside shower floor height. Schluter requires unmodified for ANY type of tile or stone over their products.

  • Ian

    I am laying 1/4 hardibacker sub floor in my bathroom. Should I use unmodified or modified thinset? I will tape and screw, etc. thank you for you help. Love your website, blog etc. thanks. Ian.

    • Roger

      Hi Ian,

      Either one works just fine, it doesn’t need to actually bond to anything. It’s just there to fill space.

  • Maurice

    Is kerabond T the same as straight kerabond ?
    Thanks
    Maurice

    • Roger

      Hi Maurice,

      No, kerabond t is a higher grade, non-sag medium bed mortar. It can be used anywhere you would use regular kerabond, though.

  • Mario

    Roger –

    I’m a DIYer and addicted to your site. Like, support group worthy.

    I’m putting in a shower and will be tiling soon (used your site – AND PURCHASED ONE OF YOUR BOOKS! – for mortar bed, cement board, curb, etc). I’m looking around like crazy for Laticrete thinset and the only one I can find is Laticrete 253 Gold (a poymer modified thinset). I cannot find Laticrete 272 or 317.

    Is Laticrete 253 acceptable for installing porcelain shower tile (4″ X 15 3/4″ subway tiles)? Also for 3″ wide glass mosiac running vertically along the corners?

    Thanks in advance! Answer and I’ll buy you a bee…soda anytime you’re in Denver!

    Mario

    • Roger

      Hey Mario,

      Yes, 253 is a very good thinset. The 272 and 317 are both unmodified, to be used over schluter products. The 253 is modified.

      • Mario

        Wow! Thanks for writing back so fast! I owe you your favorite hop-flavored carbonated beverage.

        I used a traditional waterproofing method with liner sandwiched between deck mud levels – all thanks to your website’s help.

        As it turns out, I ended up with Laticrete 254 Platinum instead of Laticrete 253 Gold. Pricey stuff! But in the grand scheme, it’s only going to cost me $40 more for two bags and it says that it will be fine, even if submerged underwater. Now if my shower is submerged underwater in Denver, my guess is that I have bigger issues, namely whatever drove my dog to burst into flames and then fill the bathroom trying to put herself out …

        Thank you again!