Pre-fabricated panels are erected one storey at a time, and each storey supports the joist or roof platform above it, distributing the load uniformly along the loadbearing wall panels. External timber frame wall panels can arrive on site either in sections or as full length walls. A basic frame will consist of vertical timber studs, top and botton timber plates, and specially engineered timbers called lintels to support loads over the openings. On the outside, a structural sheet of plywood or OSB (Oriented Strand Board) is fixed, and covered with a breather membrane. These panels are referred to as open panels. Closed panels are produced with various levels of detail depending on the company supplying the kit. Panels are insulated, and lined with a vapour barrier on the inner face by some, others will include electrical services and plasterboard finishes straight from the factory.
