If you plan to replace your roof soon, then you may be
deciding whether roof shingles, stone tiles, or another roof material is right
for your home and family. However, you may not realize that your roofing
professional may present you with other roof component options, including the
roof underlayment type you desire. While not every roof needs an underlayment,
many do.
Read on to learn what roof underlayments are, your
underlayment options, and the unique advantages and disadvantages of each
underlayment type.
What Are Roof Underlayments?
Your roof consists of many components. Your roof frame
supports your entire roof, including the wooden boards called the roof decking
the lie on top of the frame. A roof underlayment typically lies on top of the
roof decking just beneath your main roof shingles or tiles.
While your roof shingles or tiles protect your home and
decking from the elements, a good roof underlayment further protects your roof
decking and frame from the outdoor elements, especially rain water. If a
shingle or roof tile comes loose or breaks and allows rain water to seep under
your roof shingles or tiles, then the right underlayment can protect your roof
decking and frame from water damage that can occur in the form of decay or wood
rot.
Types of Roof Underlayments
There are several types of roof underlayments on the market
today.
Asphalt-Saturated Felt
Asphalt-saturated felt is water-resistant, but not
waterproof. This roof underlayment is available in two thickness options,
including 15-pound felt and 30-pound felt - 30-pound felt is thicker and
stronger than 15- pound felt.
Asphalt-saturated felt is not as heat-resistant as some
other underlayment types, and after being exposed to high heat for a long
period of time, felt underlayment can begin to lose its integrity and
waterresistance. These qualities make asphalt-saturated felt a popular
roof underlayment type in cooler areas of the country not prone to severe
weather events.
Non-Bitumen Synthetic Underlayment
While there are numerous synthetic underlayments available
today, most are composed of either polypropylene or polyethylene, which
are plastic polymers. Synthetic underlayments are waterresistant, like roofing
felt, but they do not absorb water, which makes them more resistant to mildew
growth.
Synthetic underlayments are also lighter in weight than
asphalt-saturated felt and much more resistant to heat and UV rays. These
qualities make synthetic underlayments more popular in areas of the country
with hotter climates.
However, synthetic underlayments can be a bit pricier than
asphalt-saturated felt, because of the more modern designs of these
underlayments.
Rubberized Asphalt
Rubberized asphalt underlayment is a completely waterproof
membrane that is also very heat-resistant. Since rubberized asphalt
underlayments typically come with peel-and-stick backings, they are adhered
right to the roof decking and do not need to be nailed in place. This means
that no nail holes are created in the membrane that water can seep through.
These qualities make rubberized asphalt underlayments great
options in areas of the country prone to heavy rains and on roofs that have
developed leaks and water damage in the past.
Since rubberized asphalt underlayments can cost a bit more
than other roof underlayment options, this underlayment type can be placed only
on strategic areas of a roof that are more prone to water damage, such as in
roof valleys and on roof eaves, while the rest of the roof is covered in a more
affordable underlayment type to keep your new roof costs down while obtaining
the benefits of this completely waterproof underlayment type.
If you plan to replace your home roof soon, then realize
that once you choose the main roof material you would like, you may also be
asked to choose the roof underlayment type that you desire. Every roof
underlayment type has its unique advantages and disadvantages. Contact the
roofing experts at Cal Roofing Systems Inc. today to schedule new roof installation
today.
