I have roughed in plumbing in my basement and want to build a shower. I have it framed and am ready to install 8 inch boards between my studs as barrier for the base. I wan tto pour a concrete (sloped) base on top of the concrete floor. Then mastik for the tiles of the floor. Do I need any membrane between the basement floor and the concrete shower base ? My walls will be cement board. Do I need rubber membrane on the walls or is it sufficient if I use Kurdi in just the corners before Tiling ?

Hi Dana...

You definitely want a membrane between the cement and the concrete floor for your shower.

It is a bit of work to do all of it correctly, however. For example, the floor at the shower would need to be prepitched using a cement mixture so that the water that gets down to the pan will drain via weepholes in the drain assembly. If no prepitched floor the shower floor could collect water and start to grow mold and smell, etc.

After the prepitched cement dries you would lay a layer of tar paper down and then lay the membrane in place and secure.

Install the drain assembly and then you should test the pan for water tightness by plugging the drain and filling the pan to the threshold with water for 24 hours. If no leaks you could then pour the floor and tile/grout the floor.

Check out how this guy did his job:

http://www.hoagy.org/house/HowToBuildShowerPan.html

This should be a good starting point.

In terms of the walls, are any of the walls going to be on the foundation wall or are these interior basement walls? Let me know as the answer changes according to this info.

Finally, they make some pretty cool prefab. floors. Check them out at: www.swanstone.com

Let us know what you think...

MARK

The walls are all interior using durarock - or something like that. I haven't picked that out yet.