Thermal insulation of the building pedestal and foundation — reduction of heat losses and protection from destruction.
During construction works, thermal insulation of the foundation is practically an axiom. In fact, foundation is the base of building which being underground is exposed to rigid influence of environment. Thermal insulation effectiveness depends on selection of proper insulant. Use of polyurethane foam (PU foam) is one of easiest and reliable ways.
Reason for widespread use of foundation thermal insulation is the effect of frost soil expansion that causes settlement of the foundation. This results in tilting of building, cracks formation in walls and many other problems.
Many constructors when fighting the frost soil expansion, use sand cushion so far. But the sand is not panacea. It is really not expanded and to some extent helps to prevent foundation settlement, but does not solve a problem of freezing.
Other popular material is extruded polystyrene foam (XPS). And its main competitor - polyurethane foam (PU foam). What is better?
XPS thermal insulation means sticking one or two layers of XPS slabs to concrete, or fastening to foundation with the use of «thermal insulating caps». Foundation insulation by PU foam means spraying the material on concrete surface without fastening. Result - monolithic seamless coating. This property makes polyurethane foam (PU foam) unreplaceable for foundation insulation in water-filled soils environment. What happens with polystyrene foam in such situation? Continuous water heat exchange.
- Cracks appear between the extruded polystyrene foam slabs. It is unavoidable.
- Water heated due to the influence of the foundation temperature comes up along the foundation and enters under the insulation though the cracks in XPS on the top.
- Getting cold, water travels along XPS slabs from the side of ground, displacing the water which goes to the foundation through the cracks in XPS slabs located at the bottom.
- In frost, ice can occur between XPS slabs.
Polyurethane foam insulation is a possibility to avoid such problems. Besides, benefits of polyurethane foam (PU foam) insulation of foundation lie essentially in its thermal insulating characteristics.
When insulating foundation, you warm your house in advance and save on its heating.