1 to prepare for insulating the floor first evaluate the condition of the concrete.
Concrete floor slab perimeter insulation.
Regarding the rated r value of insulation on slab on grade floors.
If you know you have issues with moisture tend to those problems before installing the insulation.
Also check the floor for smoothness and level.
However i think by far the best option is one that offers complete insulation from the ground.
Bulletin number 552 edge insulation of concrete floor slabs from branz outlines the accepted solutions for installing edge insulation or a thermal break between the slab and the perimeter wall.
Below grade need vertical insulation at the slab perimeter.
The rated r value of insulation shall be installed around the perimeter of the slab on grade floor to the distance specified.
For monolithic slab and footing the insulation must extend only to the bottom of the.
The codes are silent about whether above grade slabs need to be insulated.
These codes do not require any insulation for slabs that are more than 12 in.
Floor r value basementc wall r value slabd r value depth crawl spacec wall r value e402 1 1.
You may need to grind down significantly high spots to ensure an even surface.
In order for the slab to be independent of the foundation wall a bond break is needed between the slab which is supported on grade and the foundation wall that supports the exterior wall structure and its loads.
Insulation at the vertical slab edge and under the slab perimeter provides this bond break.
Otherwise both codes require that slab on grade floors with a floor surface less than 12 in.
A careful evaluation of these materials performance attributes against the project s needs can dramatically shrink labor and material costs.