How To Insulate A Floor Over Concrete. When installing insulation below the concrete floor, the most common method of installation. To insulate a floor that’s suspended there are two priorities:

Insulating and Finishing an Old Basement Floor Fine
Insulating and Finishing an Old Basement Floor Fine from www.finehomebuilding.com

When installing insulation below the concrete floor, the most common method of installation. Overlap edges by 6 inches and allow the sheeting to extend up about 6 inches along perimeter walls. Most slab insulation schemes i’ve seen put foam insulation under the slab, often with fancy insulation schemes at the slab edge.

Overlap edges by 6 inches and allow the sheeting to extend up about 6 inches along perimeter walls.

Then apply spray foam behind where the joists meet the walls, and any exposed concrete between the joists and xps foam. To insulate an existing concrete slab first, prepare the floor by leveling and removing the dirt on the slab’s exposed edges and measuring the distance between the slabs. If the concrete floor is dry and reasonably level, insulate directly on top with a rigid foam insulation that is impervious to moisture, air leakage and radon gas.

How to insulate a concrete floor using ecotec floorfoam.

Build a 2×4 wall from floating subfloor to joists, maintaining the space noted in #4. Install a layer of rigid foam board insulation such as styrofoam tongue and groove or styrofoam brand highload 40 (depending on the loads you have the first one provides 25 psi and the second one provides 40 psi). How to insulate a floor over concrete.

I’m thinking to lay 6 mil poly over the old slab, and then 2″ of xps over the poly, underneath the joists.

Then, lay down a layer of rigid foam insulation and seal the seams with. If you have enough clearance in the basement to add a few inches of height to the floor, one of the most effective ways to insulate the floor is to first install a sheet of polyethylene as a vapor barrier over the concrete, extending it about three inches up the walls. Most slab insulation schemes i’ve seen put foam insulation under the slab, often with fancy insulation schemes at the slab edge.

Additional gaps of ¼” are often required around the perimeter to prevent the finished floor from abutting the adjacent walls, causing puckers in the floor as the temperature rises and the material expands.

To insulate a floor that’s suspended there are two priorities: ‘as a general guide for suspended wooden floor insulation, you can use a soft insulation material like mineral wool or sheep’s wool,’ says jenny turner, product manager at insulation express. If you have enough clearance in the basement to add a few inches of height to the floor, one of the most effective ways to insulate the floor is to first install a sheet of polyethylene as a vapor barrier over the concrete, extending it about three inches up the walls.

That's not always possible, especially in existing.

When these are installed over an insulated concrete pad, the entire floor can move slightly as needed to prevent splitting and cracking. Be sure to fix any problems in the concrete floor such as cracks, spalls and water problems. I very much dislike having a hard, cold concrete floor (and, yes, even a 60*f concrete floor is cold to bare.