Kerdi shower system vs. concrete board
quicky
| Posted in General Questions on
Builder recommends the Kerdi shower system applied over the dry wall and that’s what the local tile people use too.
One of the bids from an out of town tiler, who works on high ends houses, recommended cement board instead of dry wall?
This is in regards to the shower area in the bathrooms.
Please advice
Thanks
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
Yasir,
Both can work well and produce trouble-free, long lasting showers when installed correctly by experienced trades. Both rely on membranes for their bases. A third alternative is a pre-formed shower base in a variety of materials, including those that can be tiled, with whatever waterproofing system you prefer on the walls. This doesn't depend as heavily on the skill of the installer, and is much easier to replace if you do have problems.
This is not my area of expertise, but if i understand correctly the cement board is older technology and the kerdi is newer and more water proof (concrete being water resistant). So the out of town tiler is not wrong, just out of date.
You could go with kerdi over cement board, you will need an expert to tell you if this is better then kerdi over drywall, though i will guess its unnecessary.
Yasir,
Kerdi-Board by Schlüter is one brand name of polystyrene backerboard for tile. There are other brand names of polystyrene backerboard, as well as other materials to choose from, including cement backerboard. All of these backerboard options have advantages and disadvantages. Any of them can work well if properly detailed.
For more information, see Tile Backerboard Options.
Martin-help! that url is for finehomebuildign subscribers only-
Doug,
Fine Homebuilding deserves your financial support. If you like the information available there, you should subscribe. But to whet your appetite, I will give you a glimpse of what you are missing. See the attachment below.
Cementboard is fine as long as you waterproof it. I use RedGard for this; works like a charm. The stuff is basically paintable rubber you apply over the cementboard once the seams are mortared and it provides a waterproof surface you can tile on. If your local tradesmen are not familiar with this product and want to tile right over the cementboard, you can try teaching them about RedGard. The alternative waterproofing strategy for cementboard that predates RedGard is polyethylene behind the cementboard which can work too but gets penetrated by all the cementboard fasteners so it's not 100% waterproof.
But definitely have some kind of waterproof layer. Don't let anyone build you a shower without polyethylene, RedGard, Kerdi backboard, or something similar.
By far the easiest and most sensible solution there is and I have used them all .
http://www.wedishowersystems.com/
Richard-why specifically week over shckeuter/kerdi?