Backer board

[tulegit]

I'm replacing my bath/shower walls. The surrounding drywall is 5/8" and the thickest backer board that Home Depot or Lowes sells is 1/2". What am I supposed to do to accomadate the 1/8' difference?

This is my first major remodel and I'm kinda stuck on this issue right now.

Thanks,

[jadnashua]

You can buy some slats or shims...put them behind the cbu to get it out to the same thickness as the drywall. Make sure you use a vapor barrier behind it as well. If you decide to use roofing felt rather than plastic for your vapor barrier, you could put up several layers to give you the thickness you want. If you have to buy a roll, might as well use up some of it.

[George R]

Around here you can buy a bundle of "drywall shims". They are 1 1/2" wide x 40" long and 0.080" thickness They come in bundles of 50 and are made from stiff cardboard.

I've never seen them at Lowes or HD, but M*nards carries them (put an e for the *). About $5/bundle.

They look like this

http://www.recycled-packaging.com/drywall-shims.htm

Or do like Jim said and use builders felt. However, I like the drywall shims better because the relative "thinness" of the spacers (approx 3/32") allow you to get a pretty close match to the buildup you need by stacking as many as you need, and they are the right width with no cutting required.

[Verdeboy]

Why not use 3/8" plywood then-1/4" CBU? Don't forget the vapor barrier.

[geniescience]

Double the 1/4" backerboard by using strips of itself as shims over the studs. Try it and see if you get more than 1/2'. The Hardi company used to sell only 1/4" Hardiboard and that was the method they used to recommend to build up the thickness. Costs less too. A lot less.

You'll add more thickness when you put your vapor barrier on too.

The CBU is only nominally 1/4". The batch you buy could be a lot thicker. That happens.

Tulegit, are you planning on tiling these walls?

david

[tulegit]

If i double the 1/4" backer board, it would only be 1/2" and I need it to be 5/8".

I guess added 3/8" plywood or drywall and then 1/4" backerboard would work out...although it would cost more.

Yes, I plan on tiling or adding cultured marble.

[Mikey]

Use 5/8" drywall and put a Kerdi membrane on it.

[tulegit]

that sounds interesting. I'll have to look into that. thanks.

[jadnashua]

Kerdi is a tileable membrane made by www.schluter.com. Check out their website for a small video to see someone installing it. ALso, check out www.johnbridge.com about tiling.

[geniescience]

Did I mentino that
"The CBU is only nominally 1/4". The batch you buy could be a lot thicker."

So if you are interested in a backerboard wall, look at the thinnest CBU board and see if you can use it by shimming itself with itself.

david

[Verdeboy]

Kerdi is a tileable membrane made by www.schluter.com. Check out their website for a small video to see someone installing it. ALso, check out www.johnbridge.com about tiling.

Boy, they used enough mortar installing that Kerdi to build a small house!

[Mikey]

Pretty tiny notches in the trowel, though. I don't think it would bring the walls down...

[jadnashua]

The mortar layer is really quite thin. The stuff works...

[kcchiu]

Greeting,

Does anyone know where to buy Kerdi board ?

I need to rebuild my shower room and I am planning to use it.

I know there is Wedi board too but nowhere in Internet sell it neither.

Thank you

[jadnashua]

Kerdi board has it place, but it's not that big a deal to just use the membrane itself. It produces the same result, although might take a little longer. Kerdi works fine over drywall for a shower - it is the preferred substrate. It works because the Kerdi membrane makes the drywall all be on the dry side...it is 100% waterproof.

Check out www.johnbridge.com for help with your tiling and the shower.