Sunday, April 7, 2024
HomeInstallHow To Install Roof Underlayment

How To Install Roof Underlayment

Do You Need Synthetic Underlayment

How To Install Roofing Underlayment

At Western States Metal Roofing we have a large selection of synthetic underlayment for sale. Our experts will help you choose the correct underlayment based on the specifications of your roof. In addition, we offer metal roofing and wall panels with inexpensive delivery anywhere within the United States. Our goal is to save you money while providing excellent customer service.

How To Do Teardown And Properly Install Underlayments

May 7th, 2019 BY First American Roofing

When it comes to your home, if youre not doing it right, then it may not be worth doing it all.

No matter if its the interior or exterior of your house, if youre undergoing renovations or a remodel, then you want to make sure that the professional you hire to get the job done dont cut corners.

With our Exterior Construction Fails series, we highlight some common mistakes that contractors will make in order to save some time on the job.

Today, were focusing on roof teardowns and how to properly deal with the underlayments on your roof.

First, well talk about what to do about existing shingles. Then, well go into detail on handling the drip edge of your roof and how the underlayment is a key part of properly installing the edge.

Why Roof Underlayment Is Important

Many areas require roofing underlayment. It is essential as it works as a moisture barrier, keeping your roof safe from rain and other harsh weather.

It provides your roof with an added layer of protection, supporting the work of your shingles. The underlayment and shingles are your home’s first line of defense from harmful elements caused by harsh weather conditions. In addition, they reflect the rays from the sun, block precipitation, and withstand wind.

However, shingles overlap and are not sealed at all corners. As a result, strong winds can lift the shingles, making them vulnerable to infiltration or tear-off by wind-driven rain. Shingles also become brittle as they age. Underlayment is the backup protection when shingles fail.

Read Also: How To Measure A Shingle Roof

Tools For Installing Synthetic Roofing Underlayment

  • Roofing hammer
  • Utility knife
  • 1.25″ electrogalvanized roofing nails

A successful installation starts with using the right tools for the job. This will decrease the amount of time it takes to install the synthetic underlayment, lessen the likelihood of injury, and decrease the chance of your roof leaking.

Install The Drip Edge

Roofing Underlayment

Metal drip edge isnt usually required , but it gives roof edges a nice finished look, prevents shingles from curling over the edge, and keeps water from running directly down your fascia boards.

Before you install the underlayment, fasten the drip edge that covers the fascia on the eaves. The whole length of the fascia is probably not perfectly straight, so dont snap a line just hold the drip edge snug against the fascia and fasten it through the top into the decking with roofing nails. Nail it every couple of feet.

Install the drip edge on the gable ends of the roof after you finish installing your underlayment. Start at the bottom side of the gable, and overlap the sections of drip edge a few inches as you work your way up the roof . Use a tin snips to cut the drip edge to size.

Read Also: Do I Need A Permit To Replace My Roof

Here’s How To Stay On Top Of Underlayment Installation

A roofing underlayment is a membrane that prevents water penetration. Compared to exterior roof-covering materials like metal or shingles, underlayment is the secondary barrier to moisture penetration. If the roofing underlayment is installed correctly, water that penetrates the exterior roofing materials will drain out to the exterior and away for the building. Without correct installation, water from wind-driven rain or ice dams can severely damage a roof, or even worse, the inside of buildings. The following installation tips can prevent that from happening.

Even before installation

Even before underlayment installation, determine if a permit is required for roof underlayment installation by local building authorities. If one is required, post it on the job site as required.

Ensure that the underlayment being used is compliant with the roof’s specifications and application. Are there special requirements, particularly before installing underlayment on copper or zinc metal roofing? Applicators should follow the underlayment manufacturer’s published application guidelines. Verify the delivered underlayment’s model number, grade, finish, size, options and quantity match the order precisely. Thoroughly inspect all underlayment materials for damage and proper operation.

“Membrane adhesion tests should be conducted on questionable substrates to ensure proper adhesion and to determine if approved primer is required for particular substrates,” Rowe says.


Guide To Roofing Underlayment Installation On Low Slope Roofs With Asphalt Shingles

Asphalt shingles can be used on roofs witha slope of 2:12 to 4:12 if double-coverage underlayment isused. Start with a 19-inch strip of 15 lb. asphalt-saturatedfelt along the eaves, and lap succeeding courses by19 inches as shown in Figure 2-3.

Wherever there is a possibility of ice or snow buildupor the backup of water from leaves or pine needles, installa self-adhering bituminous membrane along the eaves thatextends up the roof to a point at least 36 inches inside theinterior wall line.

An alternative approach, not widely used anymore, is to seal all laps in the lower courses of roofing felt with lap cement or asphalt plastic cement.

In areas with extensive snowfall or windblown rain,the best protection against leakage is to cover the entirelow-slope roof area with a bituminous membrane, asshown in Figure 2-4.

Vertical end laps should be at least 3 inches and horizontallaps 6 inches. If the roof changes to a steeper slope,for example, where a shed dormer joins the main roof, extendthe membrane 12 to 18 inches up the main roof slope.

Bituminous membranes are self-healing around nail holes, and because they bond fully to the sheathing, any leaks that occur cannot spread. As a safeguard against expensive callbacks, many roofers now apply membrane to the entire surface of any roof with a slope of 4:12 or less.

Also Check: How To Melt Snow Off Roof

Is Roofing Felt Necessary

Roofing felt is commonly used between roof deck sheathing and roof shingles. There are applications where felt is necessary and others where it is not. Here are some reasons why felt paper is necessary:

  • Building Code requires two layers of underlayment for low-slope roof decks between 2/12 and 4/12
  • Local Codes may require it for slopes greater than 4/12
  • Many home and roof warranties require felt paper
  • NRCA recommends bitumen, asphalt, tar, or synthetic felt for asphalt shingles
  • The NRCA recommends water-resistant underlayment for roof slopes greater than 3/12
  • Roofing felt helps to prevent pitch, uneven or sharp edges, and nails from damaging shingles
  • Some shingle warranties are void if felt isnt used
  • Necessary to meet Class A fire rating with some shingles
  • Provides additional protection to the roof decking against moisture penetration
  • When removing old shingles, fully remove and replace the old felt with new felt

Talk To The Roofing Experts

How To Install ProArmor Synthetic Roof Underlayment

Roofing underlayment can help prolong your roof life, and keep your home safer and moisture-free. Preventing water infiltration is always easier than dealing with costly repairs or damage. Get answers to more of your home-project questions on Longs website and feel free to contact us for help in all your roofing upgrades.

Don’t Miss: Will A New Roof Lower My Home Insurance

All The Facts Roofing Pros Need To Know About Synthetic Underlayment

by Rick Miller | Nov 19, 2020 | Roofing Underlayment |

Roofing felt has been around for a long time. More than 170 years ago, prospectors covered their shanty roofs with roofing felt, which was known as felt paper or tar paper back then. And it served as the primary roofing material, too, not just an underlayment. Technology evolved over the years, and roofing felt changed, becoming an underlayment beneath shingles and other types of roofing. And technology continues to evolve, which is why we now have synthetic underlayments that are even better than old-fashioned roofing felt.

What makes synthetic underlayment better? Read below and youll find all the facts you need to know!

Apply Roofing Cement To The Edges

You will need to apply roofing cement at different points of the project. Roofing cement has adhesive properties that help things stick together, which is why its commonly used in roll roofing and for other roof materials. To start off, add roofing cement to the edges before you attach the first sheet. Add roofing cement using a caulk gun and then spread it around using a brush.

Don’t Miss: How To Match Roof Shingles To House Color

An Easy Guide To Installing Roof Underlayment

As the seasons change, you may notice that your roof has started to deteriorate. Because of that, you may be wondering what kind of underlayment is best for your home. Now, its time to turn your attention to installing roof underlayment.

Though it may seem like an easy thing to do, there are some things you need to keep in mind when deciding how much will need to install your roof underlayment. This article will discuss what roofing underlayment is, the different types of roofing underlayment, its exposure life, and the things you need to consider before installing a roof underlayment.

How To Install Felt Underlayment For A New Roof

Roof Underlayment

Related Articles

Installing a roof is much more than just nailing shingles onto some boards. It starts with installing solid decking, usually plywood or oriented strand board, but that is not waterproof. It must be covered with waterproofing membrane, usually “roof felt,” also called tar paper. This is a fabric impregnated with asphalt to form a moisture barrier. It is required to block any rain that gets under or between shingles from penetrating into the wood decking. The weight or thickness needed will vary by regions, but 15-pound suffices in most locales. Installing roof felt is a two-person job.

  • Nail metal drip-edge flashing, which bends over the roof and down the edge of the facing board, on all roof edges. Fasten drip edge on eaves with galvanized nails and a hammer, about 12 inches apart, before laying roof felt. Defer putting drip edge on angled gable ends until after the felt is laid, so the metal edge will block wind from lifting the felt.

  • Start the roof felt at one bottom corner of the roof. Tack it in place at the corner, with the end flush with the end of the roof and the bottom edge of the roll right along the bottom of the roof deck, over the drip edge. Roll out about 10 feet of felt and fasten with staples or roofing nails with plastic washer heads. Use a construction stapler or a hammer. Put fasteners at least every 8 inches some suppliers recommend staples about every 4 inches. Leave the top portion of the paper loose.

  • Read Also: Can Solar Panels Be Put On A Metal Roof

    How To Install Metal Roofing Over Shingles Step By Step

    Attach your metal sheets to the framing.Because a metal roof can easily bend and become dented when you walk on it, youll need to add a series of 1×3 spacers onto the existing shingle roof.But we have a word of good news.Check out our guide to learn more about how to install metal roofing over shingles.

    Cut the metal to the right length before pulling it up on the roof.Determine the measurement of your roof.Here are the steps you need to take when installing metal roofing over shingles.How to install metal panels.

    How to install metal roofing over shingles assessing the current condition of the roof, taking proper safety precautions, and prepping the roof with underlayment or framing are all crucial steps before installing a metal roof.If your roof is stripped down to the bare plywood, you can skip this step.In this method, an approved underlayment is applied to the existing shingles without tearing off the existing shingles.In this scenario, the new underlayment serves as a defensive structure if water gets through the metal roof.

    Make sure that each sheet overlaps the first one.Make sure that each sheet overlaps the first one.Make sure that the sheets cover the whole roof area.Make sure that the sheets cover the whole roof.

    Try to remove the old roof on a sunny day.Using ring shank 8d nails,.When installing the metal roof, you will use panels to secure the metal to the existing shingle roof.When the felt is secured you can start laying the metal shingles.

    What Is Underlayment

    The underlayment is the first thing that is installed when a new roof is being fitted. It goes above the roof deck and is installed before the shingles are put in place. Underlayment can prevent any rainwater from penetrating through into the roof deck. Roofers will install the underlayment quickly as soon as the roof deck has been put down because it also protects the deck before the shingles are installed.

    There are several things that roof fitters look for when they are selecting underlayment for a roof:

    Our experienced and professional team have dealt with all kinds of roof issues over the years and we are confident that we will be able to help you as well. We have many satisfied customers that are delighted with the beautiful roofs that we have provided. We deal with all aspects of roofing service including repair and replacement. We will come and carry out a free inspection of your roof so that we can talk to you about what your options are. All estimates that we give you are without obligation so if you do suspect that there is a problem with your roof then you have nothing to lose by giving us a call.

    You May Like: How Many Roof Vents Do I Need

    What Is Roofing Felt

    Roofing felt is made of natural or synthetic materials such as wood cellulose, recycled cloth, fiberglass, or polyester. The heavy-duty felt or paper is saturated or coated with bitumen. Bitumen is a waterproof mixture of coal-tar pitch or asphalt and other viscous and sticky organic liquids.

    Felt provides a breathable, water-resistant membrane that helps shed moisture that makes it past the shingles. It is available in rolls of 15 and 30-pounds per hundred square feet. Many manufacturers offer 10-year guarantees for felt. When protected by well-maintained shingles, the underlay will last between 20 and 30-years, or as long as the asphalt shingles.

    Roof felt is often called tar paper and is commonly used in similar ways, however, they are different. Tar paper is infused with tar, and roofing felt with a bituminous substance granted, a semantic difference as both are petroleum-based products.

    Synthetic Vs Felt Underlayment

    How To Install Roof Underlayment – Rhino Roof Synthetic Underlayment and Hitachi N3808AP Cap Nailer

    The felt underlayment is the most basic roofing underlayment. It is a fabric-like material made of polyester, wood cellulose, or fiberglass. The fabric has been soaked in asphalt to make it stronger and water-resistant.

    The two available weights per 100 square feet are 15 pounds and 30 pounds. Typically, a roofer will use the thinner felt on steeply pitched roofs, and the thicker felt on lower-sloped roofs.

    On the other hand, roofing felt is not the only choice. Roofing manufacturers now produce synthetic roofing underlayment products that dont use a fabric base.

    These synthetic materials have various advantages. They are significantly more water-resistant, and their surface is non-slip, helping roofers walk on them. They also have an adhesive backing, similar to a thick sticker, allowing them to stick to the roof without using staples for better water protection.

    Roofing felt is less expensive than synthetic underlayment. However, the latter offers better protection and is commonly used as part of better overall roofing systems. To be eligible for better shingle warranty protection from the manufacturer, you may need to opt for a synthetic underlayment.

    Don’t Miss: How Long Do New Roofs Last

    How To Attach Roofing Felt

    Tack or fasten roofing felt using stainless steel ¼ to ½ T50 staples or 7/8 to 1-1/2 hot-dipped galvanized or aluminum 12-gauge shank roofing nails with a 3/8 head diameter. Use the nails with or without plastic caps. The caps help prevent tearing and are helpful for keeping the felt in place if it is windy, or if there will be a delay laying the shingles.

    Fasteners should be about 8 apart in the bottom 3/4 of the paper. Staples are faster but lack the holding power of nails. However, a roofing air nailer or air plasti-cap nailer are almost as quick. It is important to note that local building and fire codes may require cap nails instead of staples, so check the fine print.

    Pros And Cons Of Roll Roofing

    Roll roofing can provide substantial benefits for the right person. Werner said it’s relatively inexpensive, can be cut to size and installs very quickly relative to other roofing materials. Due to the ease of and speed of installation, labor costs are low. It’s also easy to transport and is an excellent choice for roofs with a low incline.

    Unfortunately, roll roofing isn’t the most durable option. It has a short lifespan of anywhere from 5 to 15 years relatively low compared to other roofing materials. The lack of layers doesnt give it as much shielding defense as different types. It’s also not the most aesthetic roofing material, and its not the best choice if you want to improve the resale value of a home.

    You May Like: How Can I Tell If My Roof Is Leaking

    Can You Roof A House Yourself

    Make no bones about itroofing is hard work. Theres no hiding from the elements. You cant be afraid of heights and you need to be pretty fit. Before committing to this how to roof a house project, try this: Get out a ladder and climb up onto your roof. If you cant walk around on it comfortably, hire a pro. If you passed this first test, go to the lumberyard or home center and throw a bundle of shingles onto your shoulder. Imagine yourself carrying that load up a laddermany, many times.

    If youre still feeling positive about this how to roof a house at this point, why not give it a shot? You can skip a lot of heavy lifting by having your roofing supplier hoist the shingles onto the roof. Be sure you spread the load evenly across the length of the roofs peak. However, dont have the shingles delivered to the roof if you still have two layers of old shingles to tear offit could be too much weight for your trusses.

    After youve obtained a permit and safely stripped the roof clean, nail drip edge flashing flush along the eave.

    Cover the rest of the roof with No. 15 asphalt-saturated felt underlayment . Each layer overlaps the lower one by at least 2 in. Follow this step by nailing drip edge along rakes , on top of the underlayment. As you did with the flashing, always lap upper pieces over lower pieces. The felt keeps the roof deck dry before shingles go on, protects against wind-driven rain as shingles fail and increases fire resistance.


    Most Popular