As part of every standard home inspection, your inspector should be providing you with a detailed analysis of the roofing system. Your inspector should observe and report on any defects found at the roof flashing and penetrations. Improper flashing and poorly sealed roofing penetrations are a leading cause of roof leaks. Your inspector should also take note of improper roof installation practices that do not conform to the manufacturers’ installation instructions. The roof of a home is a vital component. Every home owner should have a professional assessment of their potential new home prior to closing. Additionally, an itemized report should be compiled for you, accompanied by digital photographs.
Common Roof Defects
1. It is not uncommon at all to find numerous framing nails protruding from the roof’s surface during new home inspections. Some roofing companies are still nailing 2×4 “toe-boards” directly to the new roof during installation. When the boards are removed from the surface of the roof, the nails remain. This leaves minor damage to the roofing system. Quality roofing companies utilize a fall restraint harness system or proper roof jacks.
2. Another common defect observed during new home construction can be found at the ridge of the roof from the attic space. The broken decking in the image is caused by violating the span rating of the roof decking utilized. Because the ridge tends to be the most common means of travel on high sloped roofs, the decking is subject to damage. A quality roofing company would no better than this.
3. This image depicts early signs of water penetration. The flashing above was not properly sealed or fastened to the roof, which was allowing wind-driven rain to penetrate below the felt paper below. This particular defect was present on a newer home. The repair cost for this is much cheaper when identified in an early stage.
4. When the roofing system begins to fail, a common problem is the onset of water leakage. This particular roof was leaking at nearly every plumbing and vent penetration. The damage to this roof did not warrant complete re-decking, however; it does highlight the need for continued maintenance to your roofing system as the covering begins to age. If your roof is allowed to age unabated, the accelerated loss of roofing life will also adversely affect the components below.
5. This image depicts the convergence of two roof slopes that have formed a valley. It is important that a closed valley be properly bonded to prevent the buildup of debris below the shingles. As the debris is built up, naturally flowing water down the drainage plane will begin to have increased access to the felt paper below. This may lead to an eventual leak point for your roofing system that could easily have been avoided.
6. One of the more common areas of flashing failure is at the vertical transition between the chimney and the roofline. If this area is not properly sealed and flashed, the drainage of water down the vertical chimney wall will damage the substrate below the shingles. This particular home was severely damaged and a not-so-fleet-footed inspector would surely have met their demise. A proper flashing system at this location would have incorporated step flashing as well as properly installed counter-flashing.
7. Sometimes we need to slow down and go back to the basics. This image was for a new roof that was missing the required felt paper on an entire eave section. Felt paper has become a staple component of many a roofing system. The advantages of which are required by most manufacturers as well as building codes. In this particular instance, the product was bought and the labor paid for; but it was never installed. This was a case of a scrupulous contractor not fulfilling his end of the bargain, leaving the unsuspecting homeowner wholly unaware of the deed.
8. Another common, but avoidable defect can be observed in the image to the left. When installing fiber cement, wood, or stucco siding, it is important to leave a ~2″ gap between the siding and the roof. Over time, water will be pulled into the siding via capillary retraction. This will create staining and cause damage to the system. It will also increase the build up of mildew and moss on the northern plane of the roof.
9. The importance of gutter maintenance and valley cleansing is often overlooked. Valleys typically carry the burden of discharging water from multiple roof planes. If the velocity of water is impeded, the potential for water damage to the substrate below as well as the service life of the roofing system is affected. Furthermore, when there is a copious amount of organic debris on the roof, it is usually accompanied by too-close tree limbs. This combination can be costly in high wind speed areas.
Roof Inspection Checklist
- Determine the type and condition of your home’s roof covering material
- Evidence of water penetration from the roof surface and attic space
- evidence of previous repairs to the roof covering material, flashing details, skylights and other roof penetrations;
- Report deficiencies in roof fasteners where visible, adhesion of shingles,
- Observe condition of open and closed valleys
- Identify potential conditions that may lead to costly repairs or replacement as well as proper attic ventilation