Ever get tired of trying to scrub that ‘white’ (it started life as white, anyway) acrylic or fiberglass shower base? Ever try to take one out? It’s stuck, isn’t it? Ever get tired of rhetorical questions?
In order to create a shower floor for tile you must first remove that big, ugly base which seemingly attracts dirt from some unknown aspect of the magnetic force of the universe. It’s not really the magnetic force – it just feels like it. It’s actually the rubber force – as in the rubber gasket around the drain pipe.
Rather than attempting to pry the base out of there until you’re almost ready to fire up the propane torch and see if it will actually melt (it will), you can simply pry the ring from around the drain pipe and lift it out. Really.
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.
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.
What is the difference between modified and unmodified thinsets?
Which unmodified thinset is better?
What makes a modified thinset modified?
Why do you drink so much beer?
These are questions I get asked a lot, along with ‘why is my dog on fire’ (because you used the incorrect product for a specific installation).
Unmodified thinset is simply a thinset which does not have any latex polymers or other products added to it. It is essentially portland cement, silica (sand) and lime. Recipes vary, but those are the basics.
History (pay attention – there may be a quiz…)
To understand modified and unmodified you should understand why modified exists. Way back in the 1940’s Henry M. Rothberg was a chemical engineer. Back then the standard installation procedure for floor tile was the full bed method. This was a 2″-3″ deck of portland cement and sand upon which tile was installed. The need for the thickness is at the heart of the development of modified thinsets.
It needed to be that thick in order to retain enough moisture for the cement to fully cure.