Additional openings for doors and windows can be cut with standard tools at the construction site. Even though SIP s cost more than other construction systems, they require considerably less skilled labor too. Some manufacturers are also examining ways of using cementitious or fibrous core insulating materials. This foam is commonly known as beadboard. Unlike other types of foam insulation, beadboard uses pentane as the expanding agent.
Some manufacturers choose to use polyurethane and isocyanurate as the insulating material.
The foam is injected between the two wood skins under considerable pressure and, when hardened, produces a strong bond between the foam and the skins. There are also non-structural panels made of with any of the above mentioned foams. These are far weaker structurally than true SIP s and are only intended for applications such as curtain walls with no loads imposed on them and roofs where there is no attic space for additional insulation. Advantages SIP walls are superior to conventional walls in a number of ways. SIP s combine a high level of insulation with speed and ease of construction.