Roofs protect the building interior from rain, snow, sunlight, extreme temperatures, and wind. They’re also an important component in home mitigation against increasing wildfire risks.

A roof’s skeleton is made of rafters or prefabricated trusses, which rest on top of a deck board, known as sheathing. The sheathing is usually plywood or oriented strand board (OSB), but older houses may have tongue-and-groove or narrow 1-by-4 skip sheathing boards of sawn lumber. Click Visit Website to learn more.

Plywood is an essential building material for the sheathing of your roof. It’s made of thin layers, or plies, of wood, glued together with an alternating grain pattern. This creates a stronger product with greater resistance to shear and twisting forces. It’s also less expensive than dimensional lumber and is available in different grades and thicknesses, which your roofing contractor can choose from depending on the specific requirements of your project.

Plywood comes in 4-by-8-foot sheets and is rated using two letters, with A being the highest quality and D being the lowest. You can even purchase plywood that combines the grades if you need both a high and low grade in one sheet. For roof sheathing, look for CDX plywood, which has a high-grade face and back and is suitable for outdoor use.

In addition to standard plywood, you can also find specialty types that have been treated for resistance against moisture or are used in construction. For example, marine-grade plywood is designed to withstand prolonged exposure to water and is often used on boats. OSB (oriented strand board) is a cheaper alternative to plywood but doesn’t fare as well with moisture, which can cause it to swell or even delaminate over time.

Insulated plywood is another option that’s ideal for roof sheathing because it has an insulated foam core glued between two outer layers of plywood. It’s also less prone to warping and can be painted, which makes it a good choice for projects where appearance is important. Shuttering plywood is a cheap version of plywood that isn’t suitable for roofing and is often used as formwork to hold concrete while it sets.

Shingles

Whether they’re cedar or asphalt, shingles are the roof coverings that give homes their character and color. They’re usually attached in overlapping courses, or rows, and can be found on a wide range of residential buildings. Newer shingle types use different materials, but they are designed for durability and weather resistance.

A shingle’s structure is built of several layers, each with its own function. The backbone is the fiberglass mat, which offers the ideal combination of strength and flexibility. This layer is coated with a heat-activated adhesive to bond the shingle to its underlayment. Over this layer are stone granule surfacing and a protective asphalt coating. The granules are often tinted to provide color coordination with the underlayment and the roofing material.

The final layers are the ridge cap and hip shingles. These shingles aren’t nailed in like the field shingles; instead, they’re placed along the ridge of the roof, and are intended to straddle the peak and shed water down either slope. These shingles typically have a higher wind rating than those below them, and some manufacturers offer high-wind limited warranties for these shingles as well.

Many areas experience severe storms that cause shingle damage. These breaks can compromise a roof’s waterproofing, leaving it vulnerable to leaks and mold. In these cases, homeowners should look for impact rated shingles. These shingles are designed to resist the damage caused by hail and other severe weather elements. They typically have a higher price tag than those without this feature, but can save homeowners the cost of roof replacement. They can also protect a roof from water infiltration after the weather has passed, and they help to reduce the risk of roof fires.

Felt

Felt is the underlayment used in roofing and is one of the most important components for a roof to function properly. It’s a thin water-shedding layer that prevents moisture from seeping in between the roof shingles and contacting the wood roof deck. Felt also helps protect the roof from wind-driven rain and snow that can penetrate and damage the structure of the roof.

Historically, felt was made from tear-resistant paper and was saturated with tar or asphalt. The tar helped to keep the felt waterproof and gave it some strength as well. The felt was then rolled out onto the roof and cut to the proper size for installation. The thickness of the felt was determined by its weight; 15 and 30 pound felt was commonly used for residential roofs, and those products were often referred to as black or traditional roofing felt.

Today, there are other types of underlayment that can be used for roofing. Some of them are not felt and do not contain tar or asphalt but are instead composed of fibers or other materials like fiberglass, polypropylene, and polyester. Some underlayment options are even insulated to provide additional protection for the roof and help it to maintain its thermal efficiency.

While synthetic underlayment does have a number of advantages, many homeowners prefer the more traditional felt. Felt is easy to install and can be less expensive than the synthetic options. Depending on the roof and weather conditions, it may be necessary to use heavier or more layers of felt. Heavier felt is especially important if the roof is located in an area that receives heavy snowfall each year or experiences frequent winds, both of which can drive water up between the shingles and cause leaks.

Underlayment

The underlayment of a roof is a waterproof or water-resistant material that protects your home and the roof deck from the elements. It is placed directly on the roof surface before the installation of the roofing materials. It is often concealed by the roofing material, but it is essential to your roof’s longevity and the structural integrity of your house. It prevents tar from leaking under the shingles, which would damage the plywood or OSB below it, and can even cause rot in the structure itself.

Before installing a new roof, you should understand the different options available for underlayment. There are many factors that will affect this choice, including the region of your home, local building codes and the type of roof system. Additionally, the underlayment material itself may have a large impact on the performance of your roof.

Some common underlayments include asphalt-saturated felt, rubberized asphalt and non-bitumen synthetic underlayment. Felt is old-fashioned and less expensive than the synthetic options, but it is less durable and provides little protection against water damage. While rubber synthetics are much more expensive, they offer better shingle warranty protection and can be easier to work with than felt.

Choosing the right underlayment for your roof will ultimately depend on the type of shingles or other roofing material you have chosen for your home. The product permeability of the underlayment will also play an important role in determining how well your roof will perform against the elements. For instance, shingle roofs tend to have higher permeability than metal or tile roofs. This is because moisture and heat move more easily through shingle roofs. Likewise, this means that a properly installed underlayment will help to keep moisture and heat out of your home, thereby reducing energy costs.

Flashing

A roof’s flashing prevents water leaks by redirecting rainwater away from seams, joints, and openings where the roof meets vertical surfaces. It also helps shield areas where there is a difference in air pressure between the wall cladding and roof decking.

Flashing is made of metal, and it can be installed in different shapes, styles, and materials. For instance, copper flashing is an attractive choice, as it doesn’t rust. It also ages gracefully by forming a green patina over time, and it works well with many types of roofing materials. Other flashing options include galvanized steel, aluminum, and stainless-steel.

When installed properly, flashing prevents leakage from the walls of a home and roof and protects the area against damage and mold. It also provides extra weather resistance to gutters and prevents the build-up of ice dams.

Typically, flashing is used at the corners of a building, the low points where two roof slopes meet (also known as valleys), and around other features like chimneys, vent pipes, skylights, and roof protrusions. Flashing is also used to waterproof roof penetrations.

The most common type of flashing is called base flashing, and it’s usually a long piece that’s installed at the intersection of a roof and a vertical surface, such as a wall. It’s often installed with a counter flashing, which is placed opposite and above the base flashing to cover and protect it. Together, the base and counter flashings allow for expansion and contraction of the roof material without damaging the flashing. Other types of flashing include sill flashing, which is installed above doors and windows to prevent water from entering walls; parapet flashing, which caps the tops of masonry walls; and box guttering, which adds a decorative finish to a roof’s edge.