Top Rated Roof Underlayment for Rain and Snow Protection on the Market

A roof is one of the most important parts of any home. Built to protect you from the weather, its role in keeping you and your family safe and warm. It may sound like a roof is a pretty straightforward thing, but there’s more to it than first meets the eye. One of the elements of a roof that is often overlooked is referred to as roof underlayment.

Roofing underlayment is something that deserves so much more recognition for the amount of work it does to keep your roof functional. It’s a water-resistant or even waterproof barrier material. It’s installed right onto your roof deck, underneath all other roofing materials. The purpose of it is extra protection from the elements.

List & Comparison of the Best Roof Underlayments:

PhotoProductSizeExposure(UV)Details
Grace TV718355Grace TV71835536"x75'90 daysView on AmazonRead Our Review
INTERWRAP PSU30INTERWRAP PSU3036"x72'180 daysView on AmazonRead Our Review
Tyvek 40360Tyvek 403604'x250'90 daysView on AmazonRead Our Review
Grace 5003200Grace 500320036"x195'30 daysView on AmazonRead Our Review
Owens Corning 736642Owens Corning 73664242"x286'30 daysView on AmazonRead Our Review
RubberGard FSRG10X15-60RubberGard FSRG10X15-6010'x15'90 daysView on AmazonRead Our Review
Lottes Roofing 10-48-9591Lottes Roofing 10-48-959110'x15'28 daysView on AmazonRead Our Review
GAF 0970GAF 097048"x250'90 daysView on AmazonRead Our Review
Alpha Protech 48Alpha Protech 48"X250'48"x250'180 daysView on AmazonRead Our Review
LL-120 Series SuperLockLL-120 Series SuperLock4'x250'180 daysView on AmazonRead Our Review

How to choose the best roof underlayment?

You don’t have to be an expert or a builder to know all about roof underlayments. There are several important elements that come into play, and as long as you are mindful of them, you will be able to pick your roof underlayment without any help!

In order to make the task of learning easier, we have prepared a list of things for you to look out for.

Compatibility

This is a true necessity – before you pick something out, you need to shortlist the underlayments that will be suited to the rest of your roof. If you’re not quite familiar with the topic of underlayments yet, you may not be aware of the fact that the compatibility varies. Not all types of underlayments will fit each and every roof.

Traditional shingles

With this type of roof, it’s recommended that you use roofing felt. The best kind would be 15-pound roofing felt, which is known to provide excellent protection without sacrificing ventilation.

Metal roofs

If you have a metal roof, you’re better off using a roof underlayment with a synthetic layer that offers more heat resistance. This is due to the nature of metal roofing in general – it absorbs and traps much more heat than other materials.

Climate

The climate you live in is also a factor in picking the best roof underlayment. Places that are hot for the majority of the year or places with a lot of moisture are more conducive to synthetic underlayments. However, if you live in a colder location with frequent windstorms and snow, heavy-duty felt will offer a greater layer of protection.

Quality

Now that you know which type of underlayment will be best suited to your roof, you may be wondering what to consider in terms of quality. The truth is that manufacturers often claim their product to be the best of the best, but is it really?

The quality of underlayments largely depends on their durability, how well built they are, and a few other factors.

As we know that the task of picking the right option for your home may seem daunting or even overwhelming, we prepared a list of the top 10 best roof underlayments on the market right now. Read on to fully deck out your new roof!

Review of the Best Roof Underlayments:

πŸ₯‡ 1. Grace TV718355 Ice & Water Shield Roofing Underlayment

If you want something that will stand the test of time and will not crumble when repeatedly exposed to the elements, you should consider picking up this highly durable Grace Ice & Water Shield.

Features:

  • 36″ x 75″ roll
  • covers 225 square feet
  • supplied in 3 feet wide rolls
  • may be used on sloped roofs, asphalt shingles & more
  • membrane strips are also available

Do you live in an area that often experiences rain or is generally rather humid? When picking your ideal underlayment, you need to consider the fact that your roof is probably going to be dealing with a whole lot of moisture.

This self-adhered roofing underlayment features a luxury membrane composed of two materials that have waterproofing qualities: rubberized asphalt adhesive that is backed by a layer of coated high-density laminated polyethylene film. Both of these work together to ensure that no moisture ever slips through your roof.

The surface, made out of rubberized asphalt, is also backed with a foldless release paper. This protects its adhesive qualities. The release paper is very simple to remove during application. Once exposed, the rubberized asphalt will bond tightly to the deck of your roof.

If you choose this type of roof underlayment, you can expect a watertight seal that will keep you and your family safe in any kind of weather. This underlayment can be used for mechanically attached roof coverings (asphalt shingles, tile, cedar, slate), sloped roofs, or standing seam metal.

Last but not least, this roof underlayment does an amazing job at preventing leaks caused by ice dams, wind-driven rain & more. For those that want the ultimate comfort of knowing they will never have to deal with leaks, we recommend this roof underlayment.

Upsides:

  • Super durable
  • Rather long
  • Forms a watertight seal around the fasteners of your roof
  • Prevents leaks
  • Versatile – fits several types of roofs
  • Flexible but strong

πŸ₯‡ 2. INTERWRAP PSU30 Gutter-Guards Roof Underlayment

This heavy-duty roof underlayment will satisfy even the most demanding builder. For those that value reliability and durability above everything else, this is definitely one of the best picks on the market.

Features:

  • 45 mil thickness
  • 36″ width
  • 72 ft in length
  • gray
  • synthetic
  • heavy-duty

Durability is, and always will be, one of the deciding factors when it comes to roof underlayments. After all, what could be more important than ensuring the roof above your head is as strong and dependable as can possibly be?

As roof underlayments play such a pivotal part in the general quality of your home, and thus – your life, they cannot be taken lightly. INTERWRAP was clearly aware of that when they produced this ultra-durable type of underlayments.

They are a line of heavy-duty shop machines which promise (and deliver) years upon years of reliable performance. Made out of synthetic material, these roof underlayments will protect you both during and after their application.

These roof underlayments were created for straight run applications. They are easy to install and secure thanks to their ribbed surface that allows for an extra grip.

They have a reasonable 72 feet long that will cover a large area. If you are on the market for something durable, quick and easy to use, and something with a surprisingly long lifespan, you can’t go wrong with INTERWRAP.

Upsides:

  • Extremely durable
  • Ideal for straight run applications
  • Titanium series
  • A complete line of heavy-duty underlayments
  • Guranteed to deliver reliable performance
  • Easily installed

πŸ₯‡ 3. Tyvek 40360 Roof Underlayment

Reliability and top-quality are two important factors for any person who is buying roof underlayments. Tyvek knows that, and they poured that knowledge into the creation of these premium underlayments.

Features:

  • 4′ x 250′
  • one roll
  • compatible with asphalt shingles, cedar shingles and metal roofs

If you need underlayments that will go with asphalt, cedar or metal roofs, you will be pleased to know that you need to look no further. These underlayments come with a wide variety of features that make them stand out amongst a sea of others.
They can be used for repair, re-roofing or new construction. As such, whether you’re currently building a brand new home or repairing your current place, you can pick these up without hesitation.

Tyvek has a reputation for making reliable and trustworthy underlayments, and this is highlighted by the stellar reviews this product receives. These are underlayments that will protect your roof from the elements for years without fail.

One of the things you may not pay attention to when shopping is the installation. Sure that several underlayments shine when it comes to durability and overall quality, but why not also pick something that is easy to install?

Installation is made easier than ever thanks to the unique, embossed pattern etched into these underlayments. It grants supreme traction and grip while you’re walking on the roof to install them.

If you want to combine ease of use with reliability, we recommend you give this product a good amount of consideration.

Upsides:

  • One-of-a-kind embossed pattern for easy installation
  • Compatible with a variety of roofs
  • Top-notch underlayments
  • Can be used for re-roofing or new construction

πŸ₯‡ 4. Grace 5003200 Roof Underlayment

For those that live in sunny areas with a lot of heat, this underlayment is the ideal pick to protect your home from UV exposure.

Features:

  • 36″ x 195 square feet
  • comes in a roll
  • 25 mills thick
  • thick and durable
  • can stand a lot of UV exposure

Do you live in a sunny area? Whether your home is situated in a place that is hot all year round or you just experience warm summers, insulation from the heat is quite important.

As our roofs are fully exposed to the harmful UV rays, weather that is too hot can be straining for them. That is why, if you live in a place that is more often warm than cold, you should consider picking up this Grace roof underlayment.

If anything can stand the test of time in the heat of the undisturbed sun, it’s this product. They can stand up to 30 days of constant UV exposure – that is a long time!

The sun is not the only thing this underlayment will protect you from. It will make quick work of damage from other environmental causes such as the wind, rain or build-up of ice dams. Due to how versatile it is, it is recommended to be used under most roofing materials.

It can be used in a wide range of slopes, even the very lowest or highest designs. It’s worth knowing that it also has a layer of rubberized asphalt that will seal around roofing nails. A tight seal brings reliable protection from the elements at all times.

This underlayment is guaranteed not to dry out or crack and is also slip-resistant, making the installation a breeze. If your home is often exposed to extreme weather, definitely consider picking up this product.

Upsides:

  • Surprisingly thick
  • Extremely durable
  • It can withstand almost any weather condition
  • Reliable when faced with UV exposure – it can stand it for up to 30 days
  • Comes with a quick foldless release paper
  • Not prone to cracking or drying out

πŸ₯‡ 5. Owens Corning 736642 Roof Underlayment

Are you searching for roof underlayment that will work with your asphalt shingles? You’ve come to the right place. Owens Corning designed a product that is fully specialized in asphalt shingles.

Features:

  • 42-inch lightweight rolls
  • 286 square feet per roll
  • coverage per roll 9.29 squares
  • only for asphalt shingles

While at first glance the fact that this underlayment only works with asphalt shingles may seem like a downside, do not be fooled. Sometimes choosing a product that is designed specifically for just one use is beneficial.

Adapting it to just one type of roof allowed Owens Corning to fully bring out the potential of this underlayment. As such, as far as asphalt shingles go, it definitely is one of the best of the market.

The first thing you’ll notice upon picking up this product is, naturally, the installation process. The underlayment has an innovative Fusion Back Coating Technology that is combined with a non-woven surface. This makes for excellent walking conditions during the application and keeps you safe even on steep roofs.

If your area is no stranger to rain, you don’t have to worry with this roof underlayment. It comes with a set of excellent moisture repellent qualities which are topped off with extra protection against water infiltration.

Unlike some other products, you can expect this one to fully resist stretching around the fasteners, which only further improves the lifespan of this roof underlayment.

Upsides:

  • Innovative technology makes application easy even on steep roofs
  • Repels moisture & protects you from the elements
  • Stretch-resistant
  • Available in 42-inch lightweight rolls
  • Each roll contains 10 squares of underlayment

πŸ₯‡ 6. RubberGard FSRG10X15-60 Roof Underlayment

For those that prefer to purchase products that many others have tested & tried before them, we recommend this Firestone underlayment. It ranks among the most popular materials for new construction and re-roofing alike.

Features:

  • 10′ x 15′
  • 60 mil epdm roofing rubber
  • flexible material
  • provides design versatility
  • easy to install
  • ideal for DIY homeowners

The upside of purchasing this Firestone underlayment definitely lies in the fact that it’s super-flexible. It was made to accommodate even do-it-yourself homeowners and make installation as easy as possible.

Whether you’re a professional or an amateur fixer-upper, you can’t go wrong with this surprisingly flexible underlayment. If you’re the one to install it, you will be in awe of how versatile the material is. It is suited for low slope roofing applications, and it handles them very well.

It is very easy to contour to unusual shapes. This is something that cannot be said about all of its competitors, and it is definitely a highly valued quality when it comes to roof underlayments.

Once done with the installation process, you will surely admire the way this synthetic rubber compound underlayment protects you from moisture and heat. Made to withstand nearly anything, they even provide excellent resistance to UV radiation, ozone & more.

The membrane this was made of is almost always recyclable and it allows for superior thermal performance, which may, in turn, reduce energy consumption.

Upsides:

  • Flexible material
  • Perfect for new roofing and re-roofing
  • Easy to install – it can be installed by an eager homeowner without needing a whole crew
  • Protects you from the wind, hail, storm & more
  • Eco-friendly compared to many other products due to highly recyclable membrane

πŸ₯‡ 7. Lottes Roofing 10-48-9591 Roof Underlayment

Strength and durability are not all, even though this underlayment has plenty of both. If you want to truly sleep soundly, you may want to look into getting a product with a longer warranty, such as this one.

Features:

  • 10′ x 15′
  • 45 mil
  • TPO rubber
  • twice as thick as other underlayments, but lightweight
  • solid white on top side

The warranty is rarely the first thing you think of – nor should it be. The qualities of a product, roof underlayments included, should always outweigh the potential warranty. However, if you find yourself unable to decide between two similar models, it’s always good to take it into consideration.

In the case of Lottes, the warranty plays a part, but so do the general qualities of this top-notch underlayment.

When you place your order, you’ll receive a single sheet of 45 mill white TPO rubber and not EPDM Rubber. The underlayment is white on the top side, but solid gray on the backside. It also offers a lot of extra strength and durability that will have you sleeping soundly through each and every night in your home.

The TPO membrane has been reinforced with polyester fabric. This allows it to provide excellent wind uplift resistance. There’s also puncture resistance to consider, which this product protects you from as well.

For those that seek to install this product themselves, we can assure you – you can! The TPO formulation was actually developed to make room for extreme pliability and flexibility, not to mention the option to weld, during the installation. As such, it has never been easier.

With its 10 years of warranty, once you invest in this product, it’s going to last for years. As such, for those that want to maximize reliability while minimizing the time spent on installation, you can’t go wrong with this particular underlayment.

Upsides:

  • Supreme reliability
  • Long 10-year warranty
  • Innovative development provides extra pliability
  • Easily installed even by a DIY homeowner
  • Excellent wind uplift resistance
  • Puncture resistant
  • Reinforced with polyester fabric

πŸ₯‡ 8. GAF 0970 Roof Underlayment

Yet another underlayment that is known to be supremely easy to install, GAF provides a mixture of dependable protection and easy management for those that want to avoid trouble during application.

Features:

  • 48″ x 250 square feet
  • non-asphaltic polypropylene construction
  • lightweight
  • 10-square
  • durable
  • cooler surface than most asphalt felts

GAFadvertises this product as one that has enhanced walkability, and they are not wrong. The innovative surface of this roof underlayment provides increased traction, which makes for an easy application.

Other than the walkability factor, it’s also cooler to work on. Why is that? This is because of the medium-gray surface, which is up to 30 degrees cooler than your regular black asphalt felt. GAF tested it themselves with underlayments that were installed on plywood deck at 90 degrees Fahrenheit ambient temperature. Those underlayments were then exposed to direct sunlight and tested.

This underlayment is super lightweight and remarkably easy to work with. It’s clear that a lot of emphasis was placed on making this product easy to use even for people who want to install this themselves.

FeltBuster was made out of non-asphaltic polypropylene. This material promises great reliability, and compared to conventional felts, it will last longer. That’s because conventional felts can disintegrate over time, but this material is durable enough to weather any storm.

You can also expect this underlayment to lie flatter than regular felt – there should be no annoying wrinkles making application difficult and taking away from the look of your new roof.

Upsides:

  • Incredibly easy to install
  • Improved walkability
  • Lower temperatures than black asphalt felts
  • Very lightweight
  • Durable and reliable
  • Heavy-duty, tough synthetic construction
  • Tear-resistant
  • Does not absorb moisture

πŸ₯‡ 9. Alpha Protech 48″X250′ Roof Underlayment

Rex synthetic felt that can stand exposure to UV rays for up to 6 months is what you will get when you pick up this top-quality roof underlayment.

Features:

  • 48″ x 250 square feet
  • synthetic felt
  • class A fire rating

Durability and strength are two things you definitely want to find in your roof underlayment. There are other factors too, but these two are pretty much irreplaceable. As roof underlayment plays such a vital role in the comfort and protection of your household, it’s one of those things that you can’t really compromise on.

Alpha Protech truly deliver both in terms of strength and durability. This woven synthetic roof underlayment is high-strength, and it can save you up to 50% on the cost of labor and time expenditure.

This is one of the most slip-resistant underlayments in the industry, estimated to be about 20 times stronger than felt. It won’t tear off and you can be sure that it also won’t buckle when wet.

It’s extremely lightweight to the point of it being 10 times lighter per square while also being 20 times stronger than 30# felt. The rolls each include 10 squares, and despite their capacity, they still only weigh 28 lbs for an impressive 250 ft roll.

One of the best thing about this roof underlayment is that it’s ultra-resistant to UV. It can actually be exposed for up to 6 months. This is in part due to the fact that its light gray color reduces heat, granting a cooler working surface.

Upsides:

  • Impressive 50 year warranty
  • Resistant to UV
  • Can stand 6 months of exposure
  • Lightweight
  • Non-slip technology
  • High-strength
  • Class A fire rating

πŸ₯‡ 10. LL-120 Series SuperLock Roof Underlayment

If you live in a windy area, this underlayment was made for you. It can withstand strong wind and it has extra protection against tears and blow offs.

Features:

  • 4′ x 250′
  • 10x stronger than #15 felt
  • non-slip
  • anti-skid bottom coating
  • doesn’t absorb moisture

While most roof underlayments provide protection from the wind, some are more targeted than others, and this is one of them. If you know that your area experiences frequent strong winds, consider picking an underlayment that can withstand any weather.

Other than preventing blow-offs and tears, you can also count on this underlayment not to absorb moisture. It also won’t leach oil or become brittle in colder temperatures. All of these things combine to the safety of your home.

It contains post-industrial recycled polymers. If you are someone that cares about the environmental footprint they leave on the planet, you’ll be pleased to know that this underlayment is 100% recyclable.

It’s also remarkably easy to install, and most of all, safe. It features non-slip foot traction that keeps you secure even on steep roofs or during windy weather. It also has an anti-skid bottom coating. This helps to keep the underlayment from shifting or slipping.

Upsides:

  • 25-year warranty
  • Fully recyclable
  • Doesn’t absorb moisture, leach oil or become brittle
  • Suited to extremely windy weather
  • Non-slip foot traction
  • Anti-skid bottom

Info Section

We hope that our list of the top roof underlayments on the market was helpful to you. However, if you truly want to know what you’re buying, you probably still have some questions.

In order to help you understand all the different types of roof underlayment, we have prepared this Info Section. It’s going to cover everything you need to know prior to purchasing your new underlayment.

First of all, let’s talk about some of the different types of underlayment in a little more detail.

Titanium roof underlayment

This is a 15 mil synthetic roofing underlayment. It’s suited for use under shake, shingle & metal roofing. This type of underlayment will usually feature slip-resistant technologies and will not be completely smooth surfaced.

Synthetic roof underlayment vs felt underlayment

Traditional organic felt, also known as asphalt-saturated felt, is one of the top choices when it comes to the underlayment. The second top choice is known as synthetic felt.

How do you pick between the two?

First, let’s talk about what they are.

The use of organic felt was pretty much a given for most contractors for decades, and it still is today. This is mainly due to the fact that traditional felt has been around for longer. However, these days synthetic felt is definitely on the rise.

Traditional felts are:

  • Relatively low-cost
  • Readily available with the most popular materials
  • Well-known due to not being new
  • Easy to install

On the other hand, synthetic underlayment is:

  • Ultra-light
  • Very sturdy
  • Capable of resisting the elements more so than traditional felt
  • Often includes a UV coating
  • Doesn’t rot, crack or buckle
  • It is more expensive than traditional felt

The question of which one of the two will suit your roof best is up to you. It’s good to research both the options and choose what seems to work for your particular roof. Don’t be afraid to step out of your comfort zone and try something new with synthetic underlayment, though. It may be more expensive, but it also comes with many benefits.

Self-adhesive roof underlayment

This type of underlayment is designed to be placed under several types of steep-slope roofing materials. This includes asphalt shingles, tile or metal roofs. The self-adhesive factor means that the backing will seal directly to the deck, making this easy to install.

This type of underlayment is known to withstand the elements especially well and it provides great thermal stability.

Waterproof roof underlayment

Somewhat tied with the former is waterproof roof underlayment. Underlayments can either be water-resistant or waterproof. Both of these options will do fairly well at protecting your roofing, but if you live in an area that is especially wet, it’s good to go with waterproof.

Rubber roof underlayment

Contrary to popular belief, rubber roof underlayment is not a different version of rubber roofs. Rubberized asphalt underlayment is a protective material that goes underneath your external roof. Made out of recycled rubber mixed with asphalt, polyethylene and polyester, it is known for being strong and durable.

If you want some extra heat resistance, rubber is a good way to go. It’s also water-resistant and generally efficient at keeping your roof safe from all kinds of weather.

Tile roof underlayment

Back in the old days, many contractors used 30# felt underneath tile roofs. While this was an acceptable option, 30# felt has a tendency to prematurely deteriorate when exposed to the elements repeatedly. The result? A leaking roof.

These days, builders and contractors opt to use at the very least 40# felt underneath a tile roof. This type of felt is made out of a combination of asphalt and rubber, offering superior protection to the organic 30# felt.

Slate roof underlayment

Slate roofs require underlayment too, and some of them call for a double layer when the home is in an area where hard rain is quite common. This type of roofing benefits from several different types of underlayment.

If you have a slate roof, consider picking up some 30# felt. It could be asphalt-saturated or rubberized asphalt with internal reinforcement.

Ice and water roof underlayment

Did you know that there is a specific type of underlayment designed just to protect your home from ice and water? It is sometimes referred to as ice and water shield or ice and snow shield.

This type of underlayment membrane protects the vulnerable areas on your roof from ice or water damage. It’s made out of polymer-modified bitumen and it’s known to be ultra-durable.

Asphalt shingle roof underlayment

If your asphalt shingle roof is unvented and you live in a hot and/or humid area, you will require a vapor barrier that will separate asphalt shingles and the roof deck.

Some people opt to install an ice and water roof underlayment with their asphalt shingles – just for extra protection.

Polypropylene roof underlayment

This is a synthetic type of underlayment. As such, it may cost a bit more than organic felt, but it will provide extra durability and strength in return.

Many contractors in this day and age turn towards synthetic felt when it comes to the underlayment. We recommend researching it thoroughly, as it is a premium-quality product that comes with a variety of perks.

Flat roof underlayment

Flat roofs require underlayment too. For this type of roofing as well as low-sloped roofing, many contractors opt to go with rubber roof underlayment. It prevents severe damages and may end up saving you thousands of dollars in complete roof replacements.

Steel roof underlayment

On a steep-slope metal (steel) roof, you will often find non-perforated, asphalt-impregnated felt underlayment. This includes both organic felt and synthetic felt depending on the situation and the needs of a particular roofing situation.

The above covers the most common types of roofing as well as underlayment. You may be looking to think a little bit outside the box and wanting to try something new with synthetic felt. On the other hand, your roof may call for a traditional felt solution. Whichever one you pick, always remember that underlayment is a crucial element of any roof.

Roof Underlayment Q&A

By this point, you’re likely familiar with underlayment. You may have even chosen your favorite type. But do you know how to install it?

Some people opt to go down the DIY route and install their roofing themselves or with a small team. While definitely not for everyone, it is a viable option if you feel comfortable with what it entails. For those that want to give it a shot, we have prepared this Q&A section to guide you through the process.

How to install roof underlayment?

Before you start the installation of any type of roofing, you will need to comply with various safety standards. Some of them are covered below, but you will also need to read up on the particular standards in your part of the world.

Safety tips

While many roof underlayments are easy to install in this day and age, you have to remember you’re still going to need to climb your roof. There are many risks involved. As such, if you feel unsafe, it’s definitely better to spend money on a skilled contractor who will do it for you.

When working on a roof, you should always have fall protection devices on hand. This includes appropriate personal safety equipment and non-slip shoes designed for roof traction.

Before walking on the underlayment, you have to fasten it securely to the roof deck with 1-inc plastic nails. In general, if you’re forced to stand on underlayment, you should be extra careful – especially right after the installation.

If your roof is steep, you will need to use roof jacks, work supports or platforms to make sure your footing is safe and steady. Remember that these devices need to be securely fastened to the deck substructure.

Observe the locations of the power lines on your property and be extra careful when climbing a ladder. You should not come in contact with the power lines at all.

Make sure to remove debris daily from your job site and inspect the underlayment you’ve already installed to ensure no damage was done during the time it was exposed.

Lastly, be wary of the weather. Do not work too hard. Never work on the roof during high wind, rain, ice, snow, lightning storms or even high temperatures. Your health needs to come first.

With all these warnings out of the way, here’s a quick guide on how to install synthetic underlayment.

  1. Remember that it has to be installed above properly ventilated attic spaces. This is because it is considered to be a vapor barrier.
  2. Remove and replace any defective roof sheeting to keep the roof deck smooth, clean and dry prior to the installation.
  3. Start by installing the drip edge at the roof eave edges.
  4. Lay the synthetic roof underlayment horizontally, parallel to eave.
  5. The printed anti-slip side has to be facing up.
  6. Start at the bottom of the lowest roof eave. Allow yourself around a 1.5″ underlayment overhang.
  7. The lap allowance for a 3:12 pitch or greater should be a minimum of 4″ horizontal and 12″ vertical. For a 1.5:12 pitch to <3:12, horizontal overlap should be a 6″ at the least and 20″ vertical.
  8. You should only be using 1″ diameter plastic cap roofing nails. Nail down squarely into the deck. The purpose of that is to secure caps flush to the underlayment.
  9. Fasten the area in the middle of the roll (a minimum of 24″).
  10. Overlap the vertical roll end by 12″ or 20″. This depends on the pitch.
  11. Use plastic roofing cement on seams or joints.
  12. Apply a single length of underlayment roll vertically & centrally over hips and down valleys.
  13. Seal with adhesive sealant or tape.
  14. Install the final flashing material.
  15. Lastly, make sure you’ve followed local building codes and adjust accordingly.

How to install roofing felt?

To install roofing felt takes much more than just to nail the shingles onto it. It’s a rather complex process, but we’re here to guide you through the installation of roofing felt.

  1. Nail the metal drip-edge flashing. This bends over the roof and down the facing board on all roof edges.
  2. Fasten the drip edge on eaves. Use galvanized nails and a hammer for this and do it about 12″ apart.
  3. Do not put drip edges on angled gable ends until after you’ve laid all the felt.
  4. Begin laying the roof felt at one bottom corner.
  5. Tack it in place at the corner, then roll out about 10 feet of feeling and fasten it with staples.
  6. Put fasteners at least every 8 inches. Remember to leave the top portion of the paper loose.
  7. Add a second layer of felt 2 or 3 inches and fasten it. It should secure the top of the felt underneath.
  8. Continue along the roof. When you reach the endo f the roof, trim the remaining felt flush at the end.
  9. Overlap the end of a roll by about 4″ with the start of a new one.
  10. Fit the felt around vent pipes or other things that are in the way.
  11. Work your way up the roof.

How to install roof felt and drip edge?

The above method should help you install the roof felt. However, a drip edge is another story. It should be installed along the eaves prior to adding underlayment. Once the underlayment is laid down, you can place the drip edge along the gable end.

After all the underlayment is applied, place the roof drip edge flashing all the way along the gable ends on your roof. The aim is to cover the ends of your ice-and-water shields or felt paper underlayment with the drip edge.

How to install tile roof underlayment?

A tiled roof is a specific kind of roof that requires a specialized approach. While it is naturally water-repellent, roofing underlayment is an additional water barrier. As a leak is among the last things you want to happen, it’s a good addition to your home.

  1. Start by unrolling all the underlayment all along the length of any valleys on the roof where the sections join.
  2. Cut it with a utility knife.
  3. Center it over the valley.
  4. Nail it with corrosion-resistant nails long enough to go through at least ΒΎ inch.
  5. Space the nails about 12 inches apart.
  6. Next, unroll about 5 feet of underlayment onto your roof horizontally. One long edge should be even with the bottom edge of your roof.
  7. Do what you already did – fasten it and secure it.
  8. Continue to unroll the underlayment in 5-foot sections and then nail it carefully.
  9. Once you’ve finished up the first row, measure 4″ from the top side of the underlayment and mark it.
  10. Connect your marks.
  11. Align a 5-foot length of underlayment and nail it in place.
  12. Rinse and repeat until you’ve covered the entire roof.

Do you install a drip edge before tar paper?

In most cases, you will put down the ice and water shield first and then the drip edge will come after. However, this is also a bit of a case-by-case basis. If you’re unsure, we recommend contacting the shop in which you bought your supplies.

Conclusion

The importance of roof underlayment cannot be overstated. Useful in all parts of the world, this extra addition to your roof works tirelessly to keep you safe for years and years. Some of these underlayments have a 50-year warranty – that should give you a good idea on how long you can expect them to last.

Whether you’ve chosen to go with synthetic or organic, you can’t go wrong with the 10 roof underlayments we have talked about in this article. Pick one today and work on keeping your home and your family safe from leaks all year round for years on end.

About the author

Jessica Nickson

Jessica Nickson is a keen home and garden innovator with over 25 years of hands-on experience in, home improvement, landscape gardening and all things appliance related to making life easier and more interesting. You can contact her via e-mail - jessica.nickson.hd@gmail.com.

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