Question: Should I Insulate Under Garage Slab?

Should I insulate my garage slab?

“The foundation walls should be insulated instead, either outside or inside, from the sill plate to the top of the footing or frost depth whichever comes first.

“Generally speaking, however, the only place underslab insulation is required is when the slab itself is heated..

How do you insulate under a slab?

For under-slab applications, the rigid foam insulation typically should be installed over a gravel base, with a poly vapor diffusion retarder between the gravel and insulation. Additional insulation is applied along the edges of the slab, because that is a primary surface for heat loss.

Why do they put foam under concrete?

Concrete contractors learned that a layer of poly helps to keep a slab dry, because it stops upward vapor diffusion from the soil. … The foam layer isolates the room-temperature slab from the cold soil under the slab.

What kind of insulation should I use under concrete floor?

Insulating a solid ground floor below the ground bearing concrete slab can be done using either PIR insulation boards or EPS insulation boards. EPS can be a cost-effective alternative to PIR for floor insulation, and the same thermal performance can be achieved with increased thickness.

Can you use spray foam under concrete slab?

Insulating under foundation and basement slabs using SPF (spray polyurethane foam) offers certain advantages over the more common method of using rigid foam board. … Two-pound foam. Only closed-cell SPF can be used in a subslab installation; the open-cell foam does not have adequate compressive strength.

Do I need to insulate my concrete slab?

Builders with a bigger budget, especially those in cold climates, should consider installing continuous horizontal insulation under the entire slab. A continuous layer of horizontal insulation reduces heat loss in the winter, and it reduces condensation of humid air on the slab during the summer.

How much insulation do I need under a concrete slab?

A 50mm thick layer of proprietary floor slab insulation is usually enough to reach and maintain the target U value but this should be checked with an architect first. Insulation sheets should be laid tightly together with the joints staggered to avoid movement.

What kind of foam goes under slab?

expanded polystyreneRigid foam insulations, such as expanded polystyrene (EPS), have been used successfully under concrete slabs for more than 40 years. Such insulation helps reduce heat loss to the ground in residences, cold storage units, warehouses and other commercial, institutional and industrial structures.

How do you insulate concrete slab edges?

Clean the exposed slab edge and apply damp proofing as a capillary break. Install non-moisture-sensitive rigid foam board insulation (such as extruded polystyrene [XPS] or mineral wool) along the edge of the slab of a slab-on-grade foundation to meet or exceed the insulation R-value required by code.

How thick should a concrete slab be?

4 inchesStandard concrete floor slab thickness in residential construction is 4 inches. Five to six inches is recommended if the concrete will receive occasional heavy loads, such as motor homes or garbage trucks. To prepare the base, cut the ground level to the proper depth to allow for the slab thickness.

Can you insulate a garage floor?

In most cases, the garage floor will be a solid concrete slab. To insulate this, you may need to create a step-up from other internal spaces (assuming the existing floor height is the same as those in the rest of the house). If you choose to retain the slab then a damp proof membrane should first be laid.