Roofing Felt Importance

Moisture Barrier

• One of the most important functions of roofing felt is that it prevents moisture from leaking into the attic of the house. A roof is full of tiny cracks and holes, such as those around nails or between the rows of the shingles. If any moisture penetrates this initial layer of protection, the roofing felt provides the roof with another barrier that will wick away moisture so that it can't actually make an ingress into the home.

Sap Protection

• Shingles must last as long as possible to prevent moisture from getting into a home. However, if shingles are laid directly on a wood roof, the sap from the wood will shorten the lifespan of the shingles. Another value of roofing felt is that it provides a barrier between the wood and the shingles to prevent this problem.

Fire Rating

• Some roofing felt is designed to help protect the home from fire. Increasing the fire rating of the roof is always a good idea because anything that slows down the rate at which fire consumes a home allows family members more time to get to safety and allows firefighters to save what is possible of the home.

Picture Framing

• An effect called "picture framing" occurs when slight variations in the depth of the roof decking is visible through the shingles, which makes certain sections of the roof stand out and gives the roof an uneven appearance. To reduce the appearance of these types of unsightly lines, an underlayment of thick roofing felt should be used, which might not eliminate the problem entirely if the decking height differential is vast between adjacent panels, but it will reduce it.