A more recent design is the installation of a roof deck with foil-backed foam along with a second deck that is air-gapped away from the foil-backed foam to allow air to flow vertically to a ventilation outlet at the peak of the roof—it is a double deck design with an air gap. This design improves efficiency.
In the 19th century, iron, electroplated with zinc to improve its resistance to rust, became a light-weight, easily transported, waterproofing material. Its low cost and easy application made it the most accessible commercial roofing, worldwide. Since then, many types of metal roofing have been developed. Steel shingle or standing-seam roofs last about 50 years or more depending on both the method of installation and the moisture barrier (underlayment) used and are between the cost of shingle roofs and slate roofs. In the 20th century a large number of roofing materials were developed, including roofs based on bitumen (already used in previous centuries), on rubber and on a range of synthetics such as thermoplastic and on fibreglass.
The roof framing may be interrupted for openings such as a chimney or skylight. Chimneys are typically built with a water diverter known as a cricket or saddle above the chimney. Flashing is used to seal the gap between the chimney and roofing material.
As the occupied part of building has become warner, the roof space has become colder, with high performance insulation and roofing membranes leading to a cold roof space.
☑ steep driveway solutions☑ driveway barrier☑ driveway mats for cars☑ steep driveway ideas☑ polycarbonate skylight☑ house with steep driveway☑ gravel driveway solutions☑ driveway solutions curb cushions☑ driveway gaps☑ skylight dome☑ ecogrid driveway☑ driveway approach☑ driveway requirements☑ gravel driveway☑ corrugated tile☑ driveway guard☑ grass driveway systems☑ steep gravel driveway solutions