Don’t Let Roof Underlayment Be A Problem!

10A leaky roof can be quite a problem, especially when repair is not feasible due to bad weather. In cases, the only immediate solution is a bucket to catch the water dripping from the ceiling in an attempt to avoid it ruining a building’s interior. While this is a very frightening scenario, it can be easily avoided with proper underlayment.


Underlayment is a non-permeable sheet that is installed between the decking and the roof covering material. It is like a blanket used to cover a building and is secured by fasteners before the final roofing material is installed. It is also sometimes called roofing felt and comes in various sizes. Some newer varieties are easier to install because as adhesive can be applied to one side of the sheet eliminating the need for fasteners.

This crucial material is a roof’s second line of defense against outside elements and can keep weather such as rainwater, condensation, and even the outdoor temperature from infiltrating a building’s interior.


There are times when rain is accompanied by strong winds, which is when water can easily seep through the spaces between the shingles. Without underlayment, that water could flow through the decking and eventually soak the insulation, damaging any concealed structures beneath it in the process.

Avoiding Ice Dams

In the winter, heat from underlying areas melts ice on the top portion of a roof, causing water to run down the roof to lower sections that are still cold, re-freeze, and create a dam for future runoff. Then the shingles are not enough to provide necessary protection, allowing water to soak through and penetrate the interior.


Aside from waterproofing, the underlayment is also provides a certain level of thermal protection. Although older versions do not really have this quality, more manufacturers are incorporating it into products by using bubbled sheathing and sometimes by adding a reflective layer such as aluminum to one side of the sheet. This reflects heat back into the shingles, where it is distributed by the wind rather than into the living space.


There are a wide variety of underlayment materials from which to choose, with a decision usually based upon the predominant weather conditions of a particular area.

  • Asphalt Felt – This used to be the only type of material available for underlayment, combining bitumen, organic, and sometimes inorganic fiber pressed together to form a thick, flexible sheet that comes in 15 and 30 pound sheets. Extremely hot areas could cause the material to quickly turn brittle. It is also not ideal for places with a great deal of snow or rain as it has poorer water resistance than newer materials on the market; cost-wise, it is one of the cheapest materials available and may be a cost-effective option for homes located in a mild climate.
  • Synthetic – This type of underlayment usually consists of polypropylene or polyester. Although usually more expensive than conventional felt, it also lasts longer and is of better quality in terms of longevity, resistance to wear and tear, and waterproofing. Some manufacturers also incorporate other features such as self-adhering material to make installation easier without fasteners, eliminating any holes. It is also resistant to water seepage caused by damming, since all sheet edges are sealed.

Underlayment is a vital component in a roofing structure that cannot be omitted. It provides an extra layer of protection from extreme weather conditions. Deciding which type of underlayment to use can be determined by both cost and area climate concerns. Hopefully this article has provided some helpful information regarding the importance of underlayment and how to avoid any roofing problems with this valuable asset!

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Do you need to find a great College Station roofing firm? Call Schulte Roofing at 800-367-7663 to find experts who have been in business for a long time who can address the needs of all College Station area customers regarding a roof!