bathroom insulation

[Kapn]

Ok, so it's not a garage question, but this board is a wealth of info from guys who know how to do stuff the right way. And if I don't get this bathroom done, I won't ever have time to work on the ever important garage.

I'm remodeling a bath and taking the shower down to the studs. It's in a corner sharing two outside walls. What is called for in order to make it up to "code" for insulation and what can I do to make sure that it is as warm as possible and not overkill (if there is such thing) on isulation and vapor barrier?

Thanks,
Kapn

 

[6t7gto]

everything you ever wanted to know about showers and baths is here...


http://www.johnbridge.com/vbulletin/index.php?

david

 

[wrigh003]

I'm 97% done with exactly your project. Southwest corner facing shower/tub surround, etc., bathroom had to be gutted down to the studs to repair rotted floor, framing, etc. I did a tile tub surround (changed from a tiny shower), built in a niche shelf, did the flooring, etc., as well as most of the other work in there. I did hire a guy to come actually lay up the tile in the tub (my wife was ready to kill me for waiting so long on that), but I did all the prep work. For insulation, I just made sure I had batt insulation in all the exterior wall cavities, then covered the whole shebang with clear plastic for vapor barrier. Taped all those seams, and proceeded to put up my cement board and drywall.

In spite of being (at least in theory) properly insulated, it's STILL cold in there. That much tile over an unheated crawlspace, and it's going to be cold, I guess. If I could go back, I'd add a couple hundred to the budget and lay out one of those electric radiant heat mats under the floor tile. I may yet get in there and add a towel warmer just to take the edge off.

 

[kbs2244]

My master bath shower is on an outside corner.
Second floor, over the laundry room.
We just retiled it and it was easier to leave the tile on the drywall and take out big pices that to try and pull the tile off the old drywall.
That exposed the studs.
The orginal insulation was just the standard pink fiberglass stuff.
Since nrither me or the wife felt cold in there before, we just filled in some settled spots in the insulation, used cement board as a backer and retiled.
No complaints.

 

[badgerboiler]

Low voltage electric radiant under the tile with timer stat. See Warmly Yours.

I don't use much electric heat in my design work, but this is a luxury you can afford as it is a small space AND well insulated.

 

[Kapn]

Thanks for the advice. The old fiberglass stuff got wet and the paper is all messed up, so I think I'll take it down and replace it, then add a plastic barrier. I've already thought about the electric grid under the floor. It's not a large space, maybe 3x8', so will a 120 system work? Or do I need to go ahead and run a 220 line?

Kapn

 

[Kapn]

Ok, I just visited the Warmly Yours website. Very informative and well done.

 

[JMURiz]

Just a thought, but why not closed-cell foam insulation, I would think that would satisfy all your needs...

 

[beelsr]

pink fiberglass paper-faced bats in the walls, well stapled.
sheet of plastic over that, stapled in place and tape the staples/holes with HD package sealing tape.
cement board over that, glued and screwed.
water-proof/cement board mud compound (forget what it was but it was diff. than drywall compound).

Next steps depends on if it's a tiled shower or a drop-in.

And if you can, do the radiant floor on that floor. Doing that after-the-fact "bolt-on" style in the joists from below doesn't work as well.

I'm uploading some pics of mine now; will edit post in a bit....

 

[mpraddict]

pink fiberglass paper-faced bats in the walls, well stapled.
sheet of plastic over that, stapled in place and tape the staples/holes with HD package sealing tape.
cement board over that, glued and screwed.
water-proof/cement board mud compound (forget what it was but it was diff. than drywall compound).

You don't want to use both Kraft (paper) faced insulation and a plastic sheet vapor retarder in the same wall assembly. That's asking for mold. The kraft facing also has a coating on the insulation side that acts as a vapor retarder. If you double up, you could trap moisture between the two layers. Notice, they're called retarders. Vator barrier is an incorrect term, as both will allow some vapor to pass through, just at a much lower rate.

 

[larry4406]

I worked for a high end production home builder in northern VA for 6 years and in all of our houses, we used fiberglass batt insulation with the kraft paper removed in the areas of shower stalls and bath tubs. This was also the approach that the County inspectors wanted.