The requirements for roofing systems have evolved since the earliest codes were adopted. They initially addressed life-safety issues. Now, these codes address the general serviceability of a roof, including its aesthetic appearance. This is not to say that all roofing systems are equal. The Roofing Manual by the National Roofing Contractors Association (NRCA) outlines the requirements for various roof systems. Roofing systems can be considered sustainable when they have high-performance attributes.
Rafters are made from framing lumber and are called “rafters.” Trusses are pre-fabricated consists of two-by-four members and are craned into place. Sheathing is usually made of OSB or plywood, but older houses may have tongue and groove sheathing boards. Problem areas for roofing are eaves and valleys, as well as the areas where the roof meets walls and plumbing vents. To prevent damage to the rafters and other components, the roof must be properly supported.
Overlays are not recommended for roofs with steep eaves or exposed asphalt. Overlays can’t be installed over non-asphalt shingles. Curling shingles can also prevent proper installation. However, curling shingles should be addressed as soon as possible. There are many types of roofs, so it’s important to consult an expert before making a decision. Roofing over a new layer should be inspected annually.
Thermoplastic membranes have excellent durability and flexibility. They can resist punctures, tears, and chemical and oil spills. Furthermore, they can protect against bacterial growth and standing water, which can reduce the life of the roofing membrane. These membranes are also known to be energy-efficient and durable. They are commonly black in color and highly reflective. This can reduce heating and cooling costs. However, it should be noted that thin sheets may be more vulnerable to punctures.
A reroofing is not a viable option for homes with two layers of shingles. This procedure may make the roof too heavy to support any additional layers of shingles. It’s also not recommended for homes with extensive damage that requires a complete replacement of the roof. In addition to being cheaper, reroofing can reduce the time and cost involved in the process. There are some pros and cons to each type. For example, reroofing can be a good option for homes that don’t need complete roofing replacement.
Open valley is a variation of roofing systems. This type of roofing uses shingles over the top of a metal sheet and requires flashing. In addition, it allows for air flow through the attic. Indented areas, called valleys, are also covered with shingles. Flashing is a metal strip that extends over the base of the eave and prevents water from flowing behind it. However, this method is less effective than metal flashing.
A pre-roofing conference should be held several weeks prior to the actual application of the roof covering material. A roofer should invite the manufacturer of the materials, the general contractor, project manager, superintendent, foreman, and electrical contractors, as well as third-party inspection firms. The purpose of the conference is to identify any problems before the application begins. The second conference should also include representatives of the roofing materials manufacturer, mechanical contractors, electrical contractors, lightning protection system contractors, and a third-party inspection firm.