What is Roofing Underlayment?

what-is-roofing-underlaymentAs long as it doesn’t leak and looks reasonably attractive, the average homeowner probably doesn’t give their roof much thought. Still, the roof – and not just the shingles but, more importantly, the underlayment – is an integral part of a homes engineering and construction and must be maintained regularly, if it is to properly do its job. Here are a few of the most important things to know about the underlayment of your roof:

What is roofing underlayment?

While the shingles on a roof usually get all the credit for deflecting the wind and the rain and the snow, it is the underlayment that actually allows them to do so. In particular, the underlayment is the support structure of 4′ x 8′ plywood sheets to which the shingles are attached and any additional materials laid between that structure and the singles. In addition, this underlayment also supports the various flashing, vents, soffits and rakes that keep water from infiltrating under the shingles and into your home.

Does every roof need it?

As noted, the underlayment supports the shingles and the associated items that protect the entire structure from the elements. It is also an integral part of the structural support of the entire building. In fact, it actually holds the walls together unlike the floor that adds no real structural strength – contrary to a popular misconception. So, the answer to the original question posed is a resounding, “Yes!”

Types of underlayment?

The basic components of a roof underlayment are the sheathing, the felt and any specialty protective materials. The sheathing is simply the wood underneath to which everything else is attached. The felt is a material laid on the sheathing so that the shingles do not slide while being installed or at any time afterward. The specialty materials – usually incorrectly called the underlayment by most industry professionals – encompass such things as solar reflective materials, insulators and roof liners that provide extra protection from the wind and the rain.

How does a homeowner maintain it?

Just like any part of the exterior of your home a semi-annual inspection is the best way to identify immediate and potential problems. A reputable roofing repair company will do this task and provide a quote for the necessary repairs for free. It is essential that the inspectors examine the entire perimeter of the roof line, investigate for leaks in the attic as well as “walk the roof” – that is, actually climb onto the roof and feel for soft spots in the underlayment.

How to proceed

There is simply no other option than to have someone – you, a friend or a professional roofer – climb onto your roof once or twice a year and inspect for water infiltration, wind damage and general deterioration. Any potential issues should be addressed as soon as possible as Mother Nature is quite a harsh mistress when it comes to dealing with substandard materials. In short, you can pay a little to fix it now or a lot more to fix it later.