How Long Does Roof Underlayment Last? Roofing Underlaid Guide

How Long Does Roof Underlayment Last? Roofing Underlaid Guide

Got an underlaid roof or thinking of getting one? You’re in the right place. Underlayed roofs are one of the most popular solutions in the industry, and for good reason. In this article, we’re going to look at a few of the issues associated with roof underlayment.

Most importantly, how long does a roof underlayment generally last? And if yours is coming to the end of usability, what can you do about it?The reality in the roofing industry is that the general lifespan of an underlayed roof can vary quite a lot. This will depend on the specific material used, how well it was installed, and your locations. We’re going to look at a few factors that could affect the durability of your underlayed roof along with what to do if there are any issues.

So let’s get started with how long does roof underlayment last

What is an underlayed roof?

Roof underlayment is a waterproof membrane that’s installed as a barrier underneath any other roofing material. While you might look for issues or problems with your slates or shingles, many roofing issues can occur because of problems with the underlayment.

Regardless of what your roof is finished with, it will normally have a layer of underlayment. This helps protect the roof against severe weather. There are generally three main types of underlayment, and these are

  • asphalt felt
  • synthetic underylayment
  • and rubberized asphalt underlayment.

These are either waterproof or water resistant.

Wondering what the difference between waterproof and water resistant is? you’re not alone. Waterproof means completely impervious to water whereas water-resistant means the material can resist water up to some degree, but maybe not prolonged and heavy water damage. Only rubberized asphalt is completely water-proof, so this might be the best choice in areas that get a lot of rain or other precipitation.

How does a standard roof underlayment last?

The general estimated lifespan of an underlayed roof is normally around 25 years. That’s the headline quote, but as we’ll soon see, this can vary a lot depending on a number of factors.

What can affect the duration of roof underlayment?

Not all roof underlayment is the same. Even within the same groups of material, there can still be some difference in quality. Generally, you get what you pay for in roofing and that means the more expensive materials will last longer.
As we already looked at, only one type of roof underlayment (rubberized asphalt) is completely waterproof. That means if you have an underlayment that’s made from the other two materials (asphalt felt and non-bitumen synthetic) it won’t last as long in extreme weather or when it has prolonged exposure to water.

There are a few other factors that can affect the lifespan of an underlayed roof, too. Aside from rain, other weather conditions like extreme heat can cause issues. The duration of your underlayment can depend a lot on the specific climate and weather conditions of the location of your home.

How well it was installed can also be a factor. While you’d hope to have a quality roofing specialist, they aren’t all that good. That’s why you need to take time and care choosing the right roof contractor in your local area.

If your membrane was installed in a rush, it might not have been put in place securely enough. Poorly installed or cheap flashing and joins could lead to further problems with your underlayment.

How to spot when your underlayed roof needs replacing or repairing

Spotting damage or issues with your underlayment can sometimes be easy – but it isn’t always. One common sign of a problem is a leak. Leaks can be for a number of reasons, and while you still might have issues with other layers like shingles – if the underlayed membrane was intact it wouldn’t be a problem. That means if water is coming through your roof, at the very least there’s a hole in your underlay.

To find the hole, simply follow the water stream upwards. This can be a bit harder with a flat roof where streams can form anywhere, but most pitched roofs will have a stream that flows in a direct manner.

Once you’ve found the leak, you can decide what to do next. Repatching is sometimes possible, but isn’t always the best option. In severe cases, you might have to relay whole sections of the roof, or even the entire membrane. We wrote a guide about how to find leaks so you can check it out.

How to repair an underlayed roof yourself

If you’ve only got a minor issue with your underlayment, you can patch it up yourself. Remember, working on roofs can be dangerous, so you need to be careful. Especially if you’re getting up on the roof and accessing it from the outside. Make sure you’ve got all the right safety equipment and supervision. If you’re unsure what to do at any point, leave the job and hire a professional.
For small tears and holes in the membrane, you can apply new patches and use industry-standard sealant to put it in place. This can increase the lifespan of your roof considerably, and solve any minor issues. However, repatching yourself isn’t always an option. If you’ve got multiple gaps and leaks you might need to hire a professional to relay the entire roof.

Instead of tearing off and replacing the whole roof, you will have the option to overlay. This can only be done once, but is much cheaper and easier. A quality roofing professional will be able to advise you the best way to continue.

How to find the right roof contractor

If your roof problems are too hard to fix yourself, you need a professional roofing contractor to take care of the job. There will be plenty of options in the area you live, but it’s still a decision you need to take carefully. Ask people you know if they can recommend anyone, and check reviews online. Always make sure you check their portfolio and even check finished jobs if you can. Don’t take shortcuts with your roof.

Spending a bit more and getting the best job possible could add years to its durability.