When spray foam is sprayed directly underneath the floorboards of a house which has sufficient access to allow us to get under the floor, spray foam has two major advantages. Firstly, the thermal efficiency of spray foam provides effective insulation for both winter and summer climates.
Applying spray foam insulation to the underside of floors results in several positive effects. It provides effective insulation in both cold and hot seasons. It eliminates all air gaps due to the seamless nature of the spray which will further increase the effectiveness of the insulation by eliminating air flow, heat loss and the seeping in of damp moist air.
The foam is quick and simple to apply and causes a minimal upset within the home. It is simply sprayed between the joists to create a barrier which prevents the air below from coming up through the flooring and into your living environment.
Closed cell insulation should be used as opposed to open cell. If open cell is used, water vapor can travel through the open cells and get trapped between the insulation and the wooden floor base. This can lead to the rotting of the joists and sub-floor and will also cause damp to permeate into the house providing an ideal environment in which molds can grow. It can also cause the finished floor to swell and warp.
Closed cell spray foam is also used when an underfloor heating system is to be incorporated into the home. Most underfloor heating systems are insulated with polystyrene boards.
These boards have to butted up against each other almost perfectly and seamlessly in order to insulate efficiently. Any builder will readily tell you that this is an almost impossible task. Not only that, but even if one of the boards is stepped on and is cracked, then your heat seal has been broken and lost. Through those joints and cracks, coldness can leak up from below, draining out warm internal air while sucking heat from your underfloor heating pipes.