need to waterproof over CBU under shower wall tile???

frgwtchr

From reading several posts on the forum I was under the impression I needed to use some sort of waterproof membrane over the 1/2 in think cement backer boards in the shower after I taped and mudded the joints. I have seen where people used and recommended either RedGard or Kerdi. But, I just watched Amy Matthews on Sweat Equity put up porcelain tile in shower straight over the Durock walls. The HD in my area don't sell RedGard so I could order online or use Kerdi. What are my other options?

I have also seen where people put up a screwed in 2x4 as a temp brace to hold second row of tiles then put lowest row on last. If Kerdi is used I can't screw a hole threw it for the temp brace, right? So, then how do I go about tiling up the walls?

Please help! This bathroom remodel is starting to drive me cuckoo and I really don't want to screw it up!!!

Termite

Watching those DIY network home improvement shows isn't always a good thing...Their methods are often very questionable. I've seen them use mastic in showers too! Those shows make people dangerous in a lot of cases. Safe to say Amy Matthews might get a callback on that shower.

Rest assured that water will get into and through the CBU if it isn't waterproofed. RedGuard is great stuff and is certainly the economical route. Tile stores in your area will stock it or a comparable product. The Home Depots here carry it. Kerdi's great but is of course much more expensive.

The other option is to use a plastic moisture barrier on the face of the studs under the backerboard. It must weep to the tub or shower though, otherwise you'll get the inside of the walls wet. The plastic option is less than ideal!!!

As for screwing a board to the wall...
There are ways to lay tile without doing that. If you must, then just go back over your holes with a glob of RedGuard. If you use the kerdi system I wouldn't put a hole in it...If you do then patch over the hole with a small square of kerdi set in thinset I guess. A tiny hole in either system probably won't ever leak but why chance it.

Bud Cline

First of all no matter how much you like the program "Sweat Equity" keep in mind that Amy Mathews is an idiot. She has no talent that wasn't devised by a writer somewhere and a lot of her ideas are nothing short of just plain stupid. She's a celebrity not a DIY'er.

Waterproof the wallboard. Redgard can be ordered from Home Depot if it isn't on the shelf but I'll bet it's on the shelf. Go look in the wood floor adhesives isle and I'll bet you find it. Home Depot doesn't know what it is so they don't know where to display it. My local store is probably the only Home Depot in the world that displays Redgard in the tile isle, thanks to me. They aren't any smarter than Amy.

Use something for a straightedge and place it on two stacks of tile.

Elevate the tiles to where they need to be then level the straightedge and begin your second row of tile stacking it on the straightedge. Put the first row in tomorrow after the second and all subsequent rows have dried.

In place of Custom's Redgard you may have access to Mapei's HPG, Laticrete's Product # 9235, Laticrete's Floor and Wall Waterproofing. All basically the same thing. I know you can find one of them right there where you are.

Termite

My wife teases me about how I yell at the TV during those home improvement shows. Amy gets me shouting pretty good, and Bud pretty much hit the nail on the head. The best ones are the house-flipper shows where they never get a permit and they always get caught...I love that.

The one I rarely yell at is This Old House. Pretty solid professionals on that show, but it is less of a "how to" show and more of a showcase of their work.

frgwtchr

Thanks guys. I am traveling this week so I will stop at every store along the way until I find what I need. And if it isn't RedGard I will look for the Mapei substitute. Using the stacked piles of tiles for a straight edge is a great idea and alternative to screwing in a board. Knew you all could help

frgwtchr

p.s. I will continue to watch DIY shows for ideas but I will make sure to come here for actual process steps. Thanks Again.

Bud Cline

I think little miss Amy has aspirations of becomming another Ty Pennington. You have to wonder what that weirdo did (or who) to get the job he has now and become a millionaire after being a third rate carpenter making rocket ship cutouts from plywood on Trading Spaces.

Getting a few ideas from those mental dwarfs is OK but don't EVEN think about following the paths they suggest.