i’m building a shower in my bathroom remodel. i’d like to insulate all the shower walls, one outer wall, one wet wall, and one interior (as well as the whole bathroom.) my shower layers in order, will be: tile, thinset, kerdi membrane in thinset, wonderboard, a yet to be determined moisture barrier (suggestions welcome,) & finally, insulation. i’ve read on this forum not to use kraft paper backed insulation between the the moisture barrier and outer wall. can anyone tell me why, and what kind of insulation to use. also, if there’s a suggestion for moisture barrier. also, does my plan sound good?
thanks,
brie
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Assuming your schedule of materials keeps all the water out, I think you have a lot of freedom in terms of chosing your insulation material.
If water is a concern, you could always use XPS and seal it at the edges. XPS doesn't absorb water nearly as much as any of the other insulation materials and is regularly used under slabs and outside foundation walls.
I'd personally lean towards the use of a spray-in foam insulation or dense-pack cellulose. Either will stop infiltration and provide pretty good insulation properties.
pardon my ignorance, does xps come in rolls or in stiff sheets?
Extruded Polystyrene (XPS) comes in boards of differing widths and thicknesses. Inquire at your local supply house, Dowfoam is quite widespread. Cheers!
Edited 9/21/2005 4:45 pm ET by Constantin
Go to your roofing supply and they should have panels of varying thickness of foam insulation we use this for steam unit walls it cuts around pipes and can be sprayed to fully seal.
ANDYSZ2I MAY DISAGREE WITH WHAT YOUR SAYING BUT I WILL DEFEND TO THE DEATH YOUR RIGHT TO SAY IT.
Remodeler/Punchout
thank you both, i'll check it out.
brie
If you're putting up Kerdi you can do anything in the world you like. No water is going thru that.
"If you pick up a starving dog and make him prosperous, he will not bite you. This is the principal difference between a dog and a man." - Mark Twain
hey rw, so i can skip the waterproof membrane altogether? that makes sense. so, can i use insulation with the kraft paper back or no paper? thanks, brie
Brie,If you use Kerdi, you will not need the moisture barrier behind the cement board. In fact, on the John Bridge tile forum, it is strongly cautioned not to use a double barrier system, as it would prevent drying out in the event of a minor leak, leading to mildew conditions.Unfaced fiberglass is a lot easier to do good work with around pipes, etc. The rigid foam gets you more R-value per inch of thickness, and makes a good air barrier when foamed into place with a foam gun at the edges. I cut mine 1/2" undersized each way, then hold it in with a few 8's into the stud sides, which leaves 1/4" gaps all around to foam with the needle gun. This also stiffens the wall a bit, though that rarely matters.Bill
bill, thank you for your info.
brie
I see Bill beat me to the punch. I concur, and I'm not even a tile guy. A very good friend is a tilesetter, and there's no old school about him. Its all new, improved, technology. Better faster smarter. I've seen some of the stuff he's able to do with Ditra and Kerdi as options in the toolbox. I have tons of faith in Schlutter as a result. But I do enough remodels with tile in them, I don't even want to see cement board anymore. If I see a roll of orange in the truck, I'm a happy camper."If you pick up a starving dog and make him prosperous, he will not bite you. This is the principal difference between a dog and a man." - Mark Twain
hi all, yes - i'm pretty sold on kerdi. i haven't put the wall board up yet in the shower, but i might just put up drywall. it just feels so strange as i'm used to tiling on wonderboard. it's been tough trying to find a plumber to change out the cast iron drain for a kerdi drain...everyone i've spoken to has no idea what i'm talking about. i'd like to do it myself, but i've never plumbed. anyway, thank you all for your input.