by Kenton Shepard and Nick Gromicko
The purpose of the series “Mastering Roof Inspections” is to teach home inspectors, as well as insurance and roofing professionals, how to recognize proper and improper conditions while inspecting steep-slope, residential roofs. This series covers roof framing, roofing materials, the attic, and the conditions that affect the roofing materials and components, including wind and hail.
Changing to a heavier roof-covering material can cause compression cracking in drywall because the added weight can cause additional settling in the home’s structural framing.
This condition can actually be dangerous if the roof framing is not adequate to support the additional weight. Although the most likely damage will be to interior or exterior wall coverings, as you see here, there’s also a potential for catastrophic failure of the roof structure, especially in older homes.
An example of this condition may be caused by changing from a lightweight covering, such as 20-year, 3-tab asphalt shingles, which may weigh 200 pounds per square, to a heavier material, such as heavy, multiple-layer asphalt shingles or tiles, which may weigh close to 500 pounds per square.
Look for the following clues:
The homes surrounding this one have asphalt shingles and shakes. The following images are examples of compression cracks found in this home.
This crack runs between a doorway and the underside of an open walkway.
This is in a closet at the wall-ceiling and ridge intersections.
This is along the wall-ceiling intersection.
Drywall compound has cracked along the edge of the drywall tape.
This is off the corner of a window.
Learn how to master a roof inspection from beginning to end by reading the entire InterNACHI series: Mastering Roof Inspections.
Take InterNACHI’s free, online Roofing Inspection Course
Mastering Roof Inspections
Roofing Underlayment Types
Inspecting Underlayment on Roofs
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