"MUD" - What is it?
Here's some information I posted to another ceramic tile site and I thought it would be beneficial to some people here also. Maybe it will help to clear up some confusion.
is a form of tile adhesive, it comes two ways.
Modified and Unmodified, and those two ways also come in grey and white. There are more variations and more coming but this will give you the basic idea. Thinset is a portland cement type product.
comes with all the necessary additives already in the bag and you add only water, nothing else. There are a variety of modified thinsets, as the price goes up the quality (additives) goes up.
has no additives and you add water to it.
You can however include your own additives to make unmodified thinset into modified thinset and this method will result in a modified thinset that is in fact stronger than the basic modified thinset
you buy in the bag.
is the cement product used to cast the preslope of a shower at 1/4" of slope per foot and also the final slope also at 1/4" per foot. It is made up of one part portland cement to four parts sand, nothing else. Usually you mix all of the components yourself.
is the same as 'deck-mud' but fat-mud also contains lime. Lime in the mixture is required for vertical surfaces such as curbs and dams and walls. Fat-mud is usually mixed at one part portland one part lime four parts sand and you mix all of the components yourself.
is for these purposes the same thing as 'deck-mud' except you purchase sandmix already mixed in the bag, just ad water nothing else.
is for these purposes the same thing as fat-mud except you purchase mortarmix already mixed in the bag, just add water nothing else. The lime is already there for you.
can be a variety of latexs or polymers or whatevers and they are usually product specific meaning they are only compatible with recommended products and shouldn't necessarily be mixed with other products helter-skelter whenever the moods strike.
SLC's (SELF LEVELLING COMPOUNDS):
Have a very specific recipe and already contain all of the necessary additives. SLC's get mixed with a measured amount of water only and you never add anything else to the mix. You never tamper with SLC's.
are also available in a variety of mixes and are used to make repairs and corrections but usually only require water and they are formulated to stick and stay with the surface to which they are applied. Patching products come in both portland cement styles and gypsum styles. ONLY portland cement styles of patching compounds are suitable for ceramic tile projects. Gypsum based patching products should never be co-phased with tile installation setting materials. NEVER.
It is not wise to concoct your own recipes.
Just because you have something left-over from before, to think that adding some foriegn additive to any powdered product will "beef-it-up" is foolish. In some cases this random mixing is totally counter-productive and will ruin the product and void its original purpose.
I know this is confusing information. All of the above products are unfortunately referred to as "MUD" in the tile trade.
People familiar with the trade usually know which "mud" is being talked about depending on the phase the job is in.
When you refer to a particular product here please call it by its trade name not its generic name so we have some idea of what is being talked about.
-Bud Cline 5/06