I'm tiling my shower stall and screwed new backer board to the studs, what do I use on the seams?

Question

There's minute gaps not much but there's electrical wiring running through those studs so is there a need to use like "Great Stuff" or caulk or anything to make it all a sealed wall before I tile? Thanks

Answer 1

I dont know why trade professional said to use joint compound for the seams. You would use thinset only.

Answer 2

Do you already have a base and drain in the shower and are just adding tile to an existing one? If not, let me just say that building a shower is not trivial. Water drainage and water proofing are critical. If you want to see what it looks like after only a couple of years when it's done wrong, take a look here:

http://tileyourworld.com/articles/applegate_shower.htm

Even if you are just tiling the walls, you want to do like Trades said and tape and mud the joints. However, most people would probably use thinset for the joints instead of mud. I'm not sure it matters but that's seems to be the norm on the tile discussion groups. Also, it would be prudent to apply a waterproofing sealant to the backer board as well. Redgard is one made for this and available from Home Depot. Unfortunately it's about $40 a gallon but compare that to the cost of ripping out your shower a few years from now. If you put up a moister barrier behind the backer board I've seen some people recommend just putting RedGard on the screws and joints while others said do the whole thing....I'm not sure which is best.

There are too many other issues to discuss here but I'll give you a couple of links below, most are places I bookmarked as my wife and I were installing a shower. You can follow them back to some good source information and discussion. Good luck.

http://www.ontariotile.com/bathren1.html
http://www.johnbridge.com/shower_seats.htm
http://www.johnbridge.com/vbulletin/archive/index.php/t-10074.html

Answer 3

You DO NOT use silicone caulk on backer board or anywhere you're going to tile!!!

Install the Wonder or Hardi-Backer and tape your joints and seams with fibre-mesh tape (the mesh tape you find in the drywall tape area at your home improvement store), applying joint compound over it just as you do drywall. I prefer to use the 45 minute Easy Sand or Sta-Smooth drywall mud or Durabond. Once this is dry apply your thinset or tile adhesive and set you tile.

Proper grouting and following up with a grout sealer will be more than adequate for waterproofing.

Mike Lonergan
TradesProfessional, Inc.
http://www.tradesprofessional.com

Answer 4

never understand why people answer when they do not know what they are talking about....nevertheless the trades guy is correct, depending on where the seams are at, you do not need to seal them, you could just us the thin set for the tile, if the durrock is butted up together, if you have gaps more than 3.16 then i would use tape and mud

Answer 5

After multiple thousand of sq. ft. of tile, and remodeling more baths than other areas ...THANK YOU Trade pro.

You also asked about MEMBRANE in another Q, and pretty much answered your own Q.

One of the things I find a blessing and a curse is to be called to FIX what so many have Mucked up.

Steven Wolf

Answer 6

Silicone caulk.

Answer 7

Silicone caulk.