Correct detail of preformed shower pan meet the cement board of a shower wall
I'm interviewing a few contractors , and lots do not agree with me on having a vapor moisture behind the cement board. Some say that the gruot is the defense and if that break that it.
I was wondering what is the proper way for a hot mop or a preformed shower pan base meet the cement board .
do you leave a gap between the cement board and top of the pan? If you leave a gap, what is max. gap? If a gap is left, how do you seal for water sleepes?
2. If I use a moisture vapor behind a shower cement wall, can you give me thename of this sheet Poly??(Can I get this at the Orange box store?
3. To prevent any damages to the subfloor, I asking them to install tar paper before any hot mop or preformed shower pan is installs.
4.A lot of contractor either do not know or just like to use hot mop pan. What is preferrable and why one is better?
5. Do you drapy the moisture linning over the pan , and how much just a 2" over the base of the pan?
6.Is the mud goes over the pan or also under the pan?
7.Do you need a linning at the drain level if you have a pan ? Are we double dipping if we have a membrane lining and a preformed pan?
4. Is tar paper consider as a moisture vapor barrier?
Quickly, my other contractor is coming tonight.