I have searched the forum for the last hour or so, and got some great ideas, but I wanted to ask opinions on my plan.
I have a 23′ X 31′ X 13.5′ ceiling height Garage with a 24″ stem wall that I need to now turn into a kitchen. I have decided to plan my grade of the finished floor to match an existing floor level( 19″ total). The slab has been poured for 10 years, and has a vapor barrier beneath, and has never shown moisture. However I have not done the taped plastic sheet to test it.
The slab has a very slight slope, which can easily be corrected by shims
Question?
Do I need to vent the subfloor or not?
Am I overkilling this, and is there a cheaper or better way?
Thanks for the input.
Mike
Replies
I did an upfit just like this and at first I did not vent.The local inspector said later that I must vent under the floor to avoid trapping moisture.When I built the floor I used treated wood that already had a high moisture content, so the result was that the floor framing material released moisture (shrunk) hence I had to lower the shoe an even 1/4 inch all the way around the room. Odd but true, so in hindsight I would vent the floor from the outset and use #1 double kiln dried lumber!! Live and learn.
There's no way to get all the moisture out before you put up a new floor, so it should be vented.
If below the concrete was a conditioned space then you would not need to vent.
Are you stuck on wood, or would more concrete be an option?
We just extended some plumbing on 5 apartments that had the first floor raised 22" was the tallest & 4" the shallowest---- we used styrofoam to fill the void 18" on the tall one.
I'll be honest I don't know a dang thing about pouring concrete over styrofoam, and how the stuff would shrink or settle. However it sounds great for the in floor radiant heat I am thinking about. I suppose 4 sheets of 4" foam with a 3" slab might work.Any ideas on how to find out if this possible?By the way I am rural Alaska, NO inspectors.M
What part of the last frontier you in?
I've done work out on the chain & in the Priblofs
Ever see those loading docks on warehouses that are elevated above the slab. Those are poured over styrofoam.
& there's ICF's Insulated Concrete Forms that are made of polystyrene.
http://www.univfoam.com/products/construction
Geofoam
In civil engineering applications, the use of EPS means more reliable construction schedules and cost savings. EPS is unaffected by severe weather, is environmentally safe and its service life is comparable to that of other conventional construction materials. EPS Geofoam is used in geotechnical applications such as slope stabilization, lightweight fill, retaining wall and abutment backfill. It is also used as subgrade insulation under highways and airport runways.
Geofoam blocks are delivered to the site pre-cut to the required sizes and due to their light weight can be put into place by hand or with lightweight equipment.
Three major benefits EPS Geofoam are high compressive strength, low moisture absorption and low interface friction (comparable to sand). When you’re ready to investigate Geofoam for your next project, give Universal Foam Products a call!
“We need to be a country of tall fences and wide gates.”
Fred Dalton Thompson
I am in Southeast Alaska, in the banana belt!.... :-)Concrete in my neck of the woods, is expensive with a capital $$... Also shipping can be expensive.However I will definitely investigate the foam route. I suppose the foam company might supply some engineering expertise..M
Yeah if your in the Juneau Ketchikan areas concrete is a killer on freight.
“We need to be a country of tall fences and wide gates.”
Fred Dalton Thompson