Bathroom walls – State of the art?
I’m demoing my very small master bathroom right now (4’6″x7’4″). This will be my wife’s primary bathroom. I plan on installing the Toto Guinevere suite, with a different soaker style tub – I actually found one 4’6″ long! I will be doing alot of creative tilework in here, and also getting into built-in cabinetry. WHEEEEE (i’m doomed)!
I would like to know what the state of the art is currently for the walls of a bathroom. Just to get this started, here is what I have found/come up with so far as an approach:
Around tub/shower:
– Insulate the stud bays with something that will release moisture (cellulose?)
– Face the studs with 6mil plastic
– cover the studs with strips of peel&stick to seal fastener penetrations
– Face the plastic with cement board (Hardibacker), tape with alkali tape and correct mud
– Thinset and tile to the ceiling
– Epoxy grout for tile
Rest of room (note, there may be tile applied here as well):
– Foam insulate pipe to prevent sweating
– Insulate the stud bays with something that will release moisture and kill sound(cellulose?)
– nonpapered drywall
Floor:
– Troweled on latex membrane over bare smooth concrete, including the face of the sill plates
– Thinset and tile
– Epoxy grout for tile
An exaust fan and radiant heat lamps are part of the plan too.
Anything I’m overlooking? Was thinking about a rainscreen behind the hardibacker, but I don’t know if it’s needed here.
Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Replies
One topic that I hear some about is using drywall that does not have a paper face (which is probably what you mean by nonpapered), such as GP DensArmour, DensShield, DensGlass, etc. Supposedly this inhibits mold growth, as mold feeds on paper.
One piece of advice I have about such products is that some (DensShield for example) have a texture to them to help tile stick. While I would not use it in a walk in shower, I did use it on walls of a narrow bath that had a shower ring. Anyway, the texture disappears where it gets taped, so the idea would be to put DensShield where tile will go and DensGlass where it will be painted.
Epoxy grout is difficult to work with. The tiler I use says it is good for countertops, but not needed anywhere else. Mainly it is a stain stopper.
Radiant heat in the floor is great. We have NuHeat and they will custom size the mat for you with a turn around of about 10 days.
Also, heated towel bars. We got Runtal.
I'm sure you will get tons of comments about insulation, plastic, vapor barrier etc.
It seems like you're not including a vapor barrier for most of the walls (besides tub and shower walls). In a room so moist as a small bathroom, I would want to keep moisture out of the insulation and studs. I use 1" or 1/2" EPS over the studs (inside) to minimize thermal telegraphing and to be a vapor barrier.
I don't think it's necessary to leave space between hardibacker and poly. Especially if you're using epoxy grout, the poly is kind of a third line of defense.
zak
"so it goes"
We redid our own bath last year. Based on feedback/research, this is what I did:
Shower:
studs, cement board, redgard, tile + grout
rest of room:
densarmor (paperless sheetrock), paint.
the redgard was the 'state of the art' product for me. It's a water barrier that you paint on the INSIDE of the cement board, which seems to make the most sense to me, as you won't have any penetrations and it's about the closest you can get to the water.
Yes, redgard on the inside of the CB does make more sense! OK, I guess that instead of the plastic might make better sense.
BTW, in case anyone didn't see my profile, I live in Sunny SoCal. Never freezes, winters get to the middle 40's on the coldest days... both of them. Otherwise dry (like 10-20% humidity) and 70 degrees is pretty much the rule.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Ah Redguard.....not. you get what you pay for....and with redguard you aren't paying much, & are counting on it to last. Shower construction is not trivial. Myself, I think I'd go with the Schluter Kerdi, these days....
Paul,Redgard is good stuff in my experience. It is also favored on the John Bridge Tile Forum, which you need to visit. http://johnbridge.com/vbulletin/forumdisplay.php?f=1 Kerdi is the primo way to go. The great thing about a Kerdi shower is that the waterproofing is directly behind the thinset on all planes, denying the water any large volumes in which to accumulate behind the tile.It can be bad to have a double vapor barrier, since any water that got in would fester forever between the layers. I just redid my own master bath. I used Redgard in my new shower and oil primer as a VB in the rest of the walls/ceiling, and no poly behind.One wonderful thing I did was to install a mirror defogger (70 watt flat heater) wired into the light circuit. It was under $100 and the mirror is clear after a shower. Priceless feature! http://www.mirrorinthemist.com/BillEdited for clarity
Edited 6/23/2006 11:37 pm by BillBrennen
lighting?
humidistat for the fan ?
power in the cabinets
blocking in the walls / ceiling for assorted future hangers, mirrors and hooks
.
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.Wer ist jetzt der Idiot
?
Don't worry, I'll be getting to those cherry features later!Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Warm tiles on the floor. Not a big dollar output, and if it's to be primarily wifey's bath, should earn you kudu's for some time to come.
Let's not confuse the issue with facts!
If you want state of the art then go with stainless steel.
individual pieces for the walls and floor that are welded together and the seams ground down to make it "seamless".
Now it will have a bit of a prision feel. But it will be state of the art and totaly mold and water proof.
Paul,
Rather than redguard, which is really messy and smells bad, consider Nobleseal TS made by the Noble Company. It is a chlorinated plastic sheet much like that used for shower pans, but it has a non-woven "hairy" polyester surface. You thinset the Nobleseal to the cement board, sealing seams with a proprietary elastomeric sealant, then thinset the tiles. It goes up faster than redguard, is easy to tile to, and very waterproof. I did my shower surround with it, and for good measure, did the floor under the tile too, extending it up the walls slightly to create a bathtub effect. I figured this would prevent the floor from rotting out (again) from water splashed out of a tub or shower by kids, etc.
You might also wish to consider polyurethane spray foam insulation between the studs. It's essentially waterproof and is it's own vapor barrier, so you could do away with the plastic. If water gets behind your tile job, it might rot the studs, but it won't adversely affect the polyurethane insulation. You may hear other opinions on this "touchy" subject from others, but IMHO, if you want the absolute best, go with the foam.
Conrad
State of the art, a far as insulation goes is definitely sprayed in foam. Nothing to accept moisture, no air movement within the wall, no condensation on pipes, zip, zilch.
I also insulate under tubs and add a solid core door.
Extra insulation in the ceiling will increase the temperature on the surface, which in turn reduces condensation. In colder climates I'd add enough loose celulose to bring everything up to R60, and in warm climates R50.
A mixing valve to add room temperature water to the toilet will cut down on condensation there.
A humidistat will keep the fan blowing automatically until the humidity drops. Also, a fan with a very slow always on mode, in addition to normal on speeds can keep the bathroom smelling fresh during muggy months.
A remote fan with higher than normal CFM draw will be quieter and work better. Best is a whole-house exhaust fan. It cycles stale air out of bathrooms that would otherwise not get the fan turned on as often as they might.
If you have access to the back of the toilet, an additional 4" Fantec exhaust vent can be installed that is adjustable for airflow and can get some smells nearer the source, although at slightly higher noise levels.
In smallish areas such as yours, it's not unreasonable to run hardibacker everywhere and simply finish smooth/textured if so desired in the untiled areas.
Heated mirrors eliminate the condensation that often has to get wiped off after a shower.
In small, well insulated bathrooms it's common for lighting to raise the temperature considerably, especially if there are enough wats for good illumination. High dollar LED lighting can dramatically reduce heat, but it's sometimes a $100 replacement for a $1 bulb. We are talking state of the art aren't we?
I'd second the heated towel bar and radiant heat.
Good building
Just checking here, but I need to wait until after I put my tub in with its molded on tile lip before I can put up any cement board, correct?Rebuilding my home in Cypress, CA
Also a CRX fanatic!
Yes...
but you do not need to put the cement board over the tile lip, just down to it.
So I could put my CB up with a little extra over where the tub lip should be, do all my messy waterproofing, then trim it to exact height before I install the tub?Rebuilding my home in Cypress, CA
Also a CRX fanatic!
theoretically, I suppose... do you have enough room to slide the tub in from the front?
I think you're asking for extra difficulty, I'd set the tub then do the work above it instead of trying to re-invent the wheel ;)
My main concern is damaging the bathtub. I'd like to park the new $3500 toy in a construction zone for as short a time as possible! I guess I can just make a fitted plywood cover for it so I can work on it and not worry about dropping tiles, redgaurd, thinset, mortar, latex paint, tools, drywall debries, etc. on it.
It is a drop in spa tub, and there is no framing for it yet so i can put it in any which way then seal it in.
Here is a picture of where the tub will go:
http://forums.taunton.com/n/mb/at.asp?webtag=tp-breaktime&guid=0A1FE58A-8FC5-4874-823F-004F693112B9&frames=noRebuilding my home in Cypress, CA
Also a CRX fanatic!
Can I assume you are going to change that old two handle faucet for a new temperature controlled single handle while you have the wall open? If you are also using a shower head then I would raise the single handle unit much higher. Usually the shower is used more than the bathtub.
Yes, averything is getting replaced. I was thinking about moving the controls to a different location too.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
The tub should have structural sheathing behind it (inside face of the studs) as a draft stop, extending above the tub flange/tile lip, and the cement board laps over that (but the cement board doesn't touching the flange). See this Building Science pub for more details.
Paul
Depending on the location in the house and the adjacent spaces, in addition to the insulation, you might want to consider cross firring or strapping to help stop some "noise transmission". It's probably overkill in some situations, but I personally think for the cost of a bundle of firring and an hour's time, it can't hurt.
Don K.
EJG Homes Renovations - New Construction - Rentals
Don K.
I'm all over that! The wall shared with the guest bedroom is going to probably have some sort of Mooney Wall variation, possibly including sprayed foam.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
I see what you mean, I was actually thinking about sprayed in foam for those cavities.Rebuilding my home in Cypress, CA
Also a CRX fanatic!
For me, state of the art bathtub walls would be tempered or laminated glass. The backside could be painted any color or pattern. The glass would have no grout to clean and the finish is very easy to maintain.