Shower Pan Waterproofing

[jar546]

The sheetrock was removed to install the shower pan. When the sheetrock was replaced, it could not fit behind the shower pan, otherwise, it would not have had to be replaced in the first place. In your area, what would you expect to see for waterproofing this shower to comply?

 

[RLGA]

The lip around the edge of the shower pan is supposed to go behind the gypsum backer board. This overlap of the gypsum backer board creates a situation like roof shingles by shedding water towards the pan—it makes it more difficult for water to reach the studs. Also, don’t use a cut edge at that overlap with the shower pan.

 

[jar546]

The lip around the edge of the shower pan is supposed to go behind the gypsum backer board. This overlap of the gypsum backer board creates a situation like roof shingles by shedding water towards the pan—it makes it more difficult for water to reach the studs. Also, don’t use a cut edge at that overlap with the shower pan.

What if the back wall was rated?

 

[RLGA]

If rated, then the Type X gypsum board for the assembly would need to go down to the sole plate. Then, I would add the gypsum backer board over the Type X and the lip of the pan. That would be the ideal situation when properly detailed. If the situation is that the pan is sized for the framing dimension and not the clear dimension between the gypsum board, then that creates a problem.

There are intumescent sheet metal products that could be used instead of gypsum board behind the pan. I’m not able to research it and send you a link, but I will later tonight.