Deck Mud For Tile Shower Pans
The mortar layers for tile shower pans is made of simple material. The material is called deck mud. It's also called dry pack mortar, floor mud, and screed. Fat mud is different.
The deck mud is used for both the first pre-lope layer and for the top layer over the waterproof membrane. Neither layer requires any special additives.
Deck mud is made with clean sand, portland cement and water. That's it...
The basic recipe is 5 parts sand to 1 part portland cement. Some installers use more or less, but 5 to 1 is the place to start.
The sand to use is "sharp sand." It's also called concrete sand or torpedo sand. It's coarser than masonry sand, but that will work too.
Then portland cement is the name for construction cement. It comes in 94 pound bags. This is not "masonry cement," which contains lime. You don't want the lime. It makes the mix too sticky. You want portland cement.
Here's another way to get the right mix.
A popular product is Sand Topping Mix. This contains just sand and portland cement, but the ratio isn't right. But, if you add sand you can get the right recipe.
Add 50 pounds play sand to 80 pounds of Sand Topping Mix and you get the right deck mud recipe.
What about the water?
It's important first to mix the dry ingredients well so each grain of sand is coated with cement.
The easiest way to do this is to chop the sand and cement together over and over until it's thoroughly mixed. Use a mortar hoe and chop layers from one side of your mixing box to the other side, back and forth until it's mixed.
Then add very small amounts of water as you continue to chop the mixture back and forth.
Be slow to add more water. Mix very well before adding water.
You just need enough water so the mixture is evenly damp. The mix should just hold it's shape in your hand, but there should be no excess water.
Too much water causes excess shrinkage which is a no-no.
Get instructions for the first mud layer for tile shower pans at the next page. Click Here!!!