Bath niche on outside walls

[Stuart Richman]

Hi,

I'm doing a bathroom remodel and plan to put in a bathroom niche in a 3' x5' alcove type area. Ideally I would like to out the niche on the 5' wall, but that is an outside wall and the insulation would have to be removed.

Is it ok to do this? Would there be freezing or condensation issues inside the niche? Vapor barrier would be remain and the foam insulation board. The depth of the niche does not allow any thickness of insulation to be there.

(sorry for the title spelling error..it won't let me correct it to "walls")

Thank you

 

[WorthFlorida]

Between the tile backboard and the outside wall sheathing (the stud cavity), yes condensation can form. Cold enough outside temps and warm wall cavity temps can cause condensation even without being a tub or shower wall. It is really not understood why the existing insulation has to be removed and exactly where is this insulation? What type of exterior wall construction is it? Wood framed, cement block or brick? How thick is it. The DOE recommendation for your zone is R13-R15 minimum requirement.

 

[Sponsor]

 

[Stuart Richman]

Between the tile backboard and the outside wall sheathing (the stud cavity), yes condensation can form. Cold enough outside temps and warm wall cavity temps can cause condensation even without being a tub or shower wall. It is really not understood why the existing insulation has to be removed and exactly where is this insulation? What type of exterior wall construction is it? Wood framed, cement block or brick? How thick is it. The DOE recommendation for your zone is R13-R15 minimum requirement.

Hi, As you can see in the picture, it is wood framed. With the insulation still in place, the niche can not be recessed into the wall. The depth of the niche matches the width of the studs.

Thank you

 

[WorthFlorida]

OK, I misses what a niche was in your first post. Since MD can get some fairly cold weather, no insulation is not recommended. To prevent condensation in the wall cavity is not to have any air space. I just check the niche in my home and it is 3" deep. It's about the minimum you would want.

If this was my home I would remove the fiberglass to expose the outside sheathing. Glue up a 1" foam board such as 1" 3M Foam Board with a R5 value to the outside sheathing. Spread the adhesive 100% across the foam board so no air pockets can be created and press it on the sheathing. Put up the backer board on the entire wall except over the foam board. (1/2' thick). With a 3.5" stud, minus 1" for foam, add 1/2" for the backer board that gives you 3". Coat the entire wall with RedGard waterproofing and if needed a vapor barrier behind the backer board. Tile thinset should stick to the foam board with a coating of RedGARD.

If this is to be a tub, then it may be possible but for a shower only, you can add 3/4" furring strips to the wall studs to gain that depth and a little more insulation. Is the niche going to be hand made or you have something the is prefab?

 

[Jadnashua]

Personally, I would not put a niche on an exterior wall. The thing would constantly be wet from condensation while showering, and probably for long time afterward (and maybe before, but winter interior humidity levels may not be high enough without the shower.

Plus, even with some insulation behind it (many niches are foam, so there's a little insulation in the niche itself) insulation only slows the transfer of heat, so it would be like having a hole in the wall. In the summer, things would get hot in the niche, too...while somewhat insulated, the tile itself will act like a radiator and project hot or cold into the shower depending on the season.

Better to consider putting your niche either beside the shower valve or on the opposite wall. If you can afford the loss of space, you could build a partition wall against the existing one, and your niche could then fit into that cavity...the rest of the wall could be insulated, making the whole shower feel warmer.

 

[Stuart Richman]

Thank you for the input, I've decided not to put it on the outside wall. It won't fit well on the opposite wall because either stud pocket (only 2) are not centered above the tub and it would not be centered. The opposite wall is not load bearing and I could frame in a spot which I may consider.

Thank you

 

[Stuart Richman]

Thank you for the input, I've decided not to put it on the outside wall. It won't fit well on the opposite wall because either stud pocket (only 2) are not centered above the tub and it would not be centered. The opposite wall is not load bearing and I could frame in a spot which I may consider.

Thank you

 

[Jadnashua]

If the walls are open, making an opening in a load bearing wall isn't all that tough, but certainly easier in a partition wall.

 

[Stuart Richman]

If the walls are open, making an opening in a load bearing wall isn't all that tough, but certainly easier in a partition wall.

Done...thank you again for the advise.