Vapor Permeable Roof Underlayment

Follow up simulations showed if time aged roof shingles deteriorated and water penetration occurred onto the underlayment substantially higher moisture accumulation in the osb occurred for the vapor permeable underlayment.

Vapor permeable roof underlayment.

The use of asphalt felts semi permeable products has long been the underlayment of choice. Promotes long term drying of roofing assembly through vapor diffusion. According to the manufacturer the roofing underlayment features the patent pending vapor permeable polymer composite technology vppct developed by vaproshield. Or just stick with asphalt felt underlayment if you want a vapor permeable product.

Used on steep slope roofs of 2 12 9 46 degrees or greater pitch. The underlayment continues to act as another layer of protection. Todays homes are larger and more detailed than in the past making it unlikely the job will be started and completed the same day. Underlayment works in two waves.

Slopeshield plus self adhered sa a vapor permeable roofing underlayment is designed for use on steep slope roofs of 2 12 or greater pitch. They are also generally more expensive. Is managed across these two different underlayment systems. Roof underlayment test compliance.

When all of your old shingles are removed the underlayment is rolled on to protect the exposed roof from elements until the new shingles can be applied. Any material with a perm rating of 10 or greater is highly permeable. Synthetics are manufactured with a vapor permeance that can be as high or higher than asphalt felt underlayment. The second period is after the new shingles have been applied.