Can You Use Plastic Sheeting As a Shingle Underlay?

When replacing your roof one of the first decisions you have to make is what type underlayment is right for you. Of several choices, high quality professional plastic sheeting is one of the best options for the job.

Advantages

Using plastic underlay offers several advantages to the builder. The first and perhaps, most attractive, is that it is virtually waterproof and wicks away moisture more efficiently than other materials. The second major advantage to using a plastic underlay is its durability. Since it is composed of interlocking polymers it outlasts typical tar paper, according to David Toht in his book, "Smart Guide: Roofing: Step-by-Step Projects."

Disadvantages

Two drawbacks might discourage one using plastic underlay. The first is cost. A high-quality plastic underlay designed specifically for roofs often costs 60 percent more than tar felt, notes Daniel Atcheson, in his book "Roofing Construction and Estimating." The second disadvantage is plastic underlay's relative inflexibility. Because of this, it is more prone to tearing during installation or an intense wind storm.

Alternatives

Many people who decide against plastic underlayment for their roofs choose organic felt instead. Organic felt offers the builder more flexibility as well as a substantial savings in cost.

References

• Roofing Step by Step Projects
• Roofing Construction and Estimating