I am constructing a 2 stall garage addition with a full basement below and a bedroom above the garage. The basement and bedroom have radiant floor heat. Should the basement ceiling/garage floor which is concrete be insulated ? With what materials? Ridgid foam insulation? Backed with foil to reflect the heat or not? Could sheet rock be placed over this or is the risk of moisture from the garage too much?
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how are you supporting the garage floor ?
carpenter in transition
The garage floor is built just like bridge decking or free stall barns. It came in three preformed slab sections and was lifted onto the arxx system walls by a crane.
Skippy
I had this dilemma when building my house. I have a structural concrete slab for the cars, done using LiteDeck forms, that span without intermediate support just like your precase hollowcore planks.
My original design was to use hollowcore planks, but I changed to the styrofoam forms because the styrofoam was offering such a nice insulation method.
I figured that if I used the planks, I would have to fasten some sort of fur-down arrangement to the bottom side, then spray urethane foam onto the planking at a thickness of at least 5 inches, then finish with sheetrock. I didn't want to deal with all the drilling and fastening.
BTW, since I have cars to park in the garage that drip slush and water, I needed to put down a waterproof deck coating that I knew would last. I chose one by Chemrex, a system of primer, topcoat, and a rubber-particle grit that you sprinkle into the topcoat and backroll, to give it a non-slip texture.
The coatings are two-component urethanes, moisture-curing, and go on at 80 mils wet, and cure overnight. Coatings like these are used in parking garages.
Gene,
Did you pour a cap slab over the precast ?
What did you do at the precast joints ?
Did you use floor drains ?
How long has the coating been on the floor ?
How is it holding up ?
carpenter in transition
The design I didn't do was the architect's scheme, and it was 10" hollowcore planks, I recall them when quoted as 3'-4" width, then capped with a thin slab with its high thickness at rear and sides, pitched for drainage to the garage door openings.
Minimum slab thickness over the hollowcore, at the garage doors, was 2-1/2", per the architect's specs.
As I said, I elected not to do the floor with precast hollowcore, using instead a form system by Lite Deck, which made the floor a concrete structure with integral beams on 24-inch centers. Installed cost was about the same as planks, but the LiteDeck product gave me a preinsulated ceiling below, with embedded steel studs flush into the surface, on 12" centering, and we screwed the sheetrock direct.
We put out high point of slab at the perimeter, and pitched the top surface toward a center drain, sort of like a king-sized shower floor. With a Lite Deck arrangement, the slab pour is integral to the structural pour.
With your hollowcore floor down already, you'll want to dam-form the perimeter and pour the topping slab, and either pitch out the doors, or to a center drain, that you can cut through.
The deck coating bonds to the slab (we prepped with muriatic acid), and is highly elastic, so as to bridge any cracking that occurs. It has been there since '01, and looks like the day it was finished. The coating itself is elastic, and the embedded rubber particles add to the cushy bounce feel. If you drop a wrench on the floor, it does a little bounce.
We have already poured the topping slab, but a great idea to do a deck coating. Is the coating a special order item? Were you able to get it at a local building supplier? I live in a rural area and not a lot of choices. I will try to research the company on line. Thanks.
I had to make a one hour drive to pick it up from a concrete and masonry supply house. They special-ordered it for me.
Here is where to look at product specs: http://www.chemrex.com/productcatalog/detailpage.asp
Not inexpensive. But consider the alternative, that of water seeping through your ceiling and insulation.
Where you unable to put a slope on your floor.Mime was poured over plywood with temporary support. That was 25 years ago. I would definity go with the foam decking material today.But my has a significant slope to the door. Not perfect, it leaves a pool of about 3 ft dia and 1/8" depth. But never saw a hint of it under neath.Only problem that I had was some oil that I had stored in the corner before it got recycled. The container leaked some went around the edge of the slab and around the edge of the foundation wall and ran down the basement wall.
Yes, You will have lots of heat loss through that ceiling.
I would use on of the ICF lightweight decking systems.