Insulation for Room with Indoor Pool
clarkfamilyct
| Posted in Energy, Heating & Insulation on
We’re building a house with an indoor pool. We would like to avoid spray foam due to the associated health and environmental concerns. We are using cellulose in the other areas of the house. Is there any quality alternative to spray foam for an indoor pool building? Thank you!
Replies
what health and enviromental concerns do you have about foam?
Straw is fairly environmentally friendly.
How Long?
That is, do ypu plan on knocking the moldy, soggy mess down in, say, ten years?
I've participated in building two indoor 'pools.' One was a smaller pool, used in a religious rite. The other was a full-size pool with associated full-size hot tub and waterfall. You simply cannot underestimate the condensation issues. EVERY construction detail simply must address them. (Window ledges are often overlooked).
If you don't, you'll have a mold farm. Period.
Your primary defense is one that's almost never used: lots of air exchanges. Passing the air through a heat exchanger makes a real saving in air conditioning (heating or cooling) costs. This will cause a lot of the airborn moisture to drop out at the heat exchanger.
While we're at it, HOW do you plan to keep the water safe? Chlorine = corrosion. I suggest ozone treatment.
If you simply MUST use some fiberous insulation, get unfaced batts. Then make a moisture barrier with plastic sheeting and sealant. Considering all the penetrations of this sheet by nails, outlets, windows, and such, and you can see why I don't have high expectations. Expect the insulation to become a fungus farm in time.
There's simply no risk posed by any foam that compares to the risks and costs associated with mold. Don't want to spray 'inside?' Well, place foamboard on the outside of the sheathing, under the siding, and cover with Hardie-plank cement siding. (You need the fire protection of the cement). Hardie has specifications for this type of installation.
Inside the same concerns apply. Replace ordinary drywall with DuRock, or some other tileboard. Personally, I like to cover walls in such places with FRP, laminate, or some such in place of the usual painting. Nails / screws will rust, and that rust will bleed through the paint. Gypsum will absorb moisture over time and crumble.
I've noticed that tile places have aluminum molding that has a large radius- intended for use at the floor / wall connection. I like the idea of something like this, that will help keep water from pooling in corners. Better yet is some sort of floor that continues 'up' the wall several inches- think 'terazzo.' In short, you deserve a floor at least as good as the ones used in commercial kitchens.
Finally, ALL electrical receptacles should be marked "WR" on their faces, This means 'weather resistant,' and suggests a greater resistance to corrosion.
If you have anything other than a cathedral ceiling the problem isn't what type of insulation but rather how to keep the moisture from penetrating into the insulation and framing. The 3,500 sqft pool house our crew has been working on has a powered cover that rolls out over the water when not being used, big dehumidifier, moisture blocking paint to reduce the permeability into the attic and walls, exhaust fans to vent the space during warm months, and I'm guessing the key to it all working in the long run is how well everything is installed and how well the maintenance is kept up.
An Idea?
Just a wild thought, one that occurred to me last night at the Y....
I was enjoying a nice float on my back in thir indoor pool, when ... Drip! Water dripped from the ceiling ont to me.
Could, I wonder, you make a section that was deliberately poorly insulated, as a way to attract all the condensation to one place? If so, you could design this place to collect and drain the water back into the pool. Moisture thus collected would not be available to penetrate elsewhere.
Think of it as a 'passive' dehumidifier.
How to do it? Instal a window high up, with uninsulated metal framing. Have the sill on the inside slope as the outside one slopes. Place a simple gutter under the sill to collect the water, and use a simple bit of tubing to direct the water back to the pool.
Drawbacks? Well, even if successful, this would work only when the glass was colder than the inside air.