They both come in various rated compressive strengths from 10 psi to about 80 psi. Q.How much insulation is necessary under a typical radiant slab? Say you use an average (and relatively inexpensive) rating of 40 psi, then the insulation will support: 40 psi x 8” wide tire x 12” long tire print = 3,840 lbs. The key is getting the right mix of crushed rock, he says, a product without a lot of fines (grit) in it that would hold moisture. The house walls are R19 batts in 2x6 with 2" iso sheets on the garage side with FireRock over that. The fill inside the garage perimeter is native and lift packed pit run. Rigid foam insulations, such as expanded polystyrene (EPS), have been used successfully under concrete slabs for more than 40 years. Insulating below slab-on-grade foundations. The first thing to consider when looking into different types of concrete floors is why it’s so important to insulate the floor slab. A. Q.How much insulation is necessary under a typical radiant slab? Frost non-susceptible fill is ≤6% passing the 200 sieve, so crushed stone counts, but putting washed crushed stone on fine material is a problem. The garage is unheated. Surprisingly, the fall off from there to the garage doors (about 18') was only 1-2 degrees according to the thermocouple sensor I use. How to Insulate a Garage Floor Above a Concrete Slab Insulation on Slab. The back ten feet of the garage structure is an unheated workshop area, separated from where the cars park by a framed wall (2x4) and door. The slab is pretty consistent as noted and running about 12 degrees warmer than the outside concrete apron. Use of any material over or next to a finer material must be considered against fines migration. lift of washed 3/4-in. There is a 2" XPS foam layer inside the short foundation walls, right down to the footings, protected by 1/2" Durock and capped by 2x6 to cover the top of the foundation and dadoed to capture the top of the Durock. The garage doors are internally foamed polyurethane and seal quite well. If you've sealed the garage up tight enough to function in winter - are you okay with high levels of condensation and high humidity in summer? During the winter, snow and ice will linger inside the garage for days. The fact that about 1/3 of the wall area in the garage is shared with the main house could be a major source of the warmth we are experiencing. Forklifts to be used in the building impart 8,000 pounds of force at the wheel, which has a 6-inch by 10-inch tire footprint on the slab. Insulation located below grade, as required in Climate Zones 4 through 8, should extend the length specified in the table by any combination of vertical insulation, insulation extending under the slab, or insulation extending out perpendicular to the building Insulation extending perpendicular away from the building should be protected by pavement or by not less than 10 inches of soil. The kiss mark of the door gasket can be seen in the sun fade and grime lines. What type of garage doors are you using? Once you get past the initial condensation and the floors warm up, you should be able to maintain similar indoor/outdoor humidity levels. Up to 80% of heat loss in a floor slab occurs around the edges. My thinking was to isolate the fill under the garage slab/foam and thus keep it at something like the roughly 50 degree neutral soil temp one would expect below 12' of depth. 4/10/2012 4 Heated Slab “If you need bearing locations for the lift, you could cut out small areas of the foam where the lift will sit, but that’s probably not necessary, and if you really want to know you will need an engineer to look at the loads and the slab performance.”. Martin, sounds similar to what we see sometimes in Ottawa. For Under Floor Slabs, FOAMULAR® 150 or 250 can be used for residential and light commercial applications where floors are subject to normal loads; use FOAMULAR® 400, 600, or 1000 for industrial applications where floor areas will be exposed to heavy loads. Reclaimed EPS or XPS is often a third the cost of new material. If ground under the home is cooler than the basement temperature, which is the case in almost every climate year round, heat will naturally try to escape through the concrete slab. If somebody accidentally or deliberately leaves the garage door open for a while in this scenario five or ten or twenty years down the line, what happens? The walls are a total of 4 1/2" of foam outside of the sheathing so roughly R16. The basic concept is that the building should have continuous insulation all around the structure. Small addendum. (I get to feel green that way.) Yet, slab-on-grade insulation can be arranged in a number of configurations, each with pros and cons. You must be a magazine subscriber to access this feature. In order to provide you with a detailed explanation, we will go back to the basics of building science. The foam only slows the rate of transfer, so without heat being added by the unused pex tubing, I suspect the neutral temperature of the slab and soil is buffering the dips in temperature. My bad. “Pinning the apron to the slab is just doweling some #4 rebar into the garage slab at each door,” writes Dave Richeson. The current slab has zero insulation on each side. Slab-on-grade insulation. A resource to point them to for example calculations is the article “Right-sizing Under-slab Insulation,” in the April 2014 issue of Structure magazine. Concrete Slab Insulation Amount, Placement, & Vapor Barrier Placement for (Solar) Radiant Heated Floors, What insulation thickness is needed under a passive-solar heated slab floor? Here that would be R-10 inside the walls to a depth of 24 in. While you can apply insulation over the concrete slab, that requires adding wood subflooring and other components that add to the cost and complexity of the project. Of course, it might also make it harder to heat to a relatively high temperature. If they have an exact situation match then so much the better. Question about slab insulation. Bringing home a freshly washed car to a well sealed garage can create a slick film of condensate. Image Result For Slab On Grade Garage Foundation Rigid Insulation Pouring Concrete Slab Home Construction . See the link below for the original (free) document. See more ideas about building foundation, insulation, building construction. Installing insulation prior to the pouring of a concrete slab floor improves the energy efficiency of the floor and makes it more comfortable. The cement contractor really recommended against trying to float the slab on the 3" reclaimed XPS as a completely unbound element. The first thing to consider when looking into different types of concrete floors is why it’s so important to insulate the floor slab. Really you can forget the imposed vehicle load and just work out the concentrated load - which should be minimum 9kN for vehicles up to 2500kg. The worst case will be jacking up. Insulating the slab Connecting slab and aprons As long as I don't ding it with the snow shovel it seems to do fine. The wall has a brick ledge cast in. Originally I had planned for the door gasket to kiss down on just the foam line, but best made plans of mice and men sometimes go awry. Jul 15, 2020 - Explore Building Supply Stop's board "Under Concrete Slab Insulation", followed by 113 people on Pinterest. Charlie, good point on the humidity levels. I manage the meltwater issue by scooping up the melting snow shortly after it falls off the cars with a shovel. EPS insulation in an under-slab application. He’s also adding #3 rebar 18-in. “Are you planning to heat the garage now or eventually? Slabs also have an advantage when it comes to reducing air leakage, although it’s still important to seal penetrations where pipes, wires and ducts enter the conditioned space. I am not using the pex. - Under slab insulation: Will just buying 2" 4x8 XPS sheets at a big box store be sufficient on top of the vapor barrier? I would guess a functional R28-30. Refer to CT DOT M.02.05 for a reference material, link below and image attached. Ours work quite well. The slab was mostly 47F and the apron 35F. Courtesy of Insulfoam. Fdn Detail Garage1 Garage Slab Floor Plans . Thanks for your input. “I would never, ever place concrete over sand, even with a vapor barrier under it,” says davidmeiland. I chose to insulate the exterior of the entire house/garage foundation with reclaimed XPS. This patented product is a modern solution for your radiant floor, basement floor, garage, driveway and metal building floor. “[It’s] generally done after the larger slab is poured and the forms wrecked. I should take some temperature readings and post those for your information. Up to 80% of heat loss in a floor slab occurs around the edges. If the interior is not climate protected (freezes in the winter), frost protection of the slab is required by ICC codes. Also, the seeming inconsistency of R value for the walls of the garage is due to remembering I have 4.5" total foam on those walls thanks to the fake stucco base foam. The manufacturer’s call for 4 in. I would like to heat the garage to keep it a few degrees above freezing, and temporarily heat the smaller workshop area to a comfortable temperature only when needed. 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