Technically, no, underlayment isn't always required beneath asphalt shingles. At least not in locations where there is no code! Building codes differ from area to region, but almost all need felt or synthetic roofing underlayment. The only time I would recommend skipping it is if you have a very large roof that is made of standing seam metal, then felt or similar material may be enough protection. Otherwise, get the roof covered.
The purpose of underlayment is to provide a stable base upon which to lay other materials. It does this by absorbing shock waves from heavy traffic and providing a flat surface upon which to attach other materials such as tar paper or metal roofing. Underlayments come in several forms including sheet goods such as plywood, fiberglass, and carbon fiber; foam products such as polyurethane; and even cork and dirt cheap tiles from China! The choice should match your roof's design and intended use. For example, if you want to save money but still retain good performance, consider using recycled plastic bottles as an underlayment. They work well and are environmentally friendly.
Asphalt shingles are the most common type of roofing material used by homeowners. They're easy to install and maintain and can last for many years if cared for properly.
Should I put underlayment on my roll roofing? It depends on your budget, but placing an underlay is a personal preference rather than a requirement. While roll roof underlay is not expensive, it does provide several levels of protection. Make certain that the underlay is nailed down and then rolled to ensure that it is nice and flat.
What are the benefits of using underlayment? There are many advantages including added comfort, durability, and aesthetic appeal. Underlayments also prevent ice from building up underneath the membrane which could cause damage to your roof. Finally, underlayments keep dirt and other debris off the surface of the membrane which prevents it from getting dirty and needing replacement sooner.
There are two types of underlayments: fiberglass and polyester. Both work well with roll roofing, but there are some differences between the two. Fiberglass has more of a white color when new which changes over time to gray or silver. This is because it is exposed to the elements such as sun and rain. Polyester has less of a white color when new and remains this way longer. It can be cleaned with a vacuum or brush and will never go gray or silver like its fiberglass counterpart.
Fiberglass underlayments are made of 100 percent glass fibers and are durable enough for most roofs. They tend to be more expensive than polyester but will last longer too. Fiberglass rolls come in one-inch and three-quarter-inch widths and lengths.
With roof slopes of 4:12 (18 degrees) or more, NRCA recommends a single layer of no. 15 asphalt-saturated underlayment for asphalt shingles. NRCA recommends a minimum of two layers of no. 15 underlayment for roof slopes between 3:12 (14 degrees) and 4:12 (18 degrees).
For less than 18 degrees, NRCA recommends a single layer of no. 15 asphalt-saturated underlayment.
Asphalt-saturated underlayments are available in sheets that are either saturated or dry. Saturated underlayments must be applied while they are wet, which means they must be installed before the roof is completed. Dry underlayments can be installed after the roof is complete but must be removed before applying the topcoat to allow for proper adhesion to the roof substrate.
Dry underlayments will usually come with instructions on how to prepare the surface prior to application, such as sanding or otherwise roughening the surface to help the adhesive grab onto the roof substrate.
The best way to ensure a long life for your asphalt shingle roof is through regular maintenance. Some basic roof care procedures include cleaning off any debris from around the housekeeper station area, inspecting the roof for damage, and repairing leaks immediately. More extensive repairs may also be needed.
Shingles, shakes, and other roofing materials cannot perform to their maximum capacity without suitable underlayment. Because self-adhesive roof underlayment should not be used over existing roofing materials, you must first remove the old shingles. Then, lay down the self-adhesive piece of roofing material.
The old shingles should be removed using a hammer and pry bar. Make sure that you do not damage the new shingle when removing the old one. Then, lay the self-adhesive piece of roofing material over the existing shingles or other surface.
Self-adhesive roofing products are easy to use and install. They do not require any special tools for installation. The adhesive on the back of the membrane sticks to the metal in your house so it can hold up against weather conditions. You can also move it around if needed. There is no need to screw it into the ceiling or trim of your home.
Underlayments will help give your roof proper support and insulation. It will also allow the roofing material to adhere properly to your home. Without this layer, the shingles or other roofing materials would be unable to withstand wind, rain, and other elements that cause damage to roofs.
You should consider how much you want to spend before choosing an underlayment for your roof.