Concrete slab floors are typically insulated with polystyrene board.
Under concrete floor insulation options.
Insulating concrete slab floors timber frame floors are typically insulated with polystyrene boards or sheet insulation made from glasswool fibreglass wool polyester wool polyester mix and mineral wool.
Although building codes differ by region builders typically use r5 and r10 insulation under the concrete slab but floors insulated with r20 contain the heat in your basement far better than those insulated with lower r values.
The good news is that all the mentioned products can be found right here at insulation shop.
R 5 78 rigid foam insulation model 320817.
Floor 1 garage 3 under slab 5 more ways to filter.
Another option for insulating your concrete floor are some more flexible materials such as knauf rock wool insulation slabs or rockwool insulation slabs which also offer a level of sound insulation apart from known as being great and versatile insulators.
It is the longest lasting and the highest r value insulation that can be put into place.
Underslab floor insulation rockwool rigid stone wool boards used as a continuous layer of insulation under a concrete slab can provide the thermal efficiency and mechanical properties required as an alternative to rigid foam.
The most expensive option.