A roof inspection checklist for owners and buyers

The National Roofing Contractors Association (NRCA) recommends that homeowners inspect their roofs at least twice a year, preferably in spring and fall, and again after severe weather such as a hailstorm. On a steep roof the inspection can usually be done from the ground or from a ladder at the roof’s edge. NRCA does not recommend that homeowners walk on a roof unless they have the experience and equipment to do it safely, and it recommends hiring an experienced roofing contractor for any repairs the inspection turns up.

From the ground

NRCA describes a maintenance inspection as a careful look at the roof and the surfaces that meet it, such as sidewalls and chimneys, noting anything abnormal or deteriorating. These are the items its guidance and the National Park Service’s slate brief point to:

• On an asphalt shingle roof, shingles that curl or split. NRCA calls these evidence of deterioration.
• Dislodged or missing shingle tabs, which NRCA says should be repaired to keep the roof weathertight.
• On slate, tile, wood or metal roofs, cracked, broken or missing pieces.
• Slates sliding out of position. The Park Service brief says this can mean the nails holding them have corroded while the slates themselves are sound.
• Leaves and other debris in valleys, gutters and roof drains, where NRCA says debris collects and limits drainage.
• Flashing at chimneys, walls, valleys and skylights. The brief calls flashings the weakest point in any roof and says even a small pinhole can let in a large amount of water.

From the attic

The Park Service brief suggests checking rafters and roof sheathing from the attic for moisture stains and pushing an awl into the wood to find rot. It warns that very old slates that have started to delaminate hold moisture and can rot the wood next to them even when there is no visible leak.

Not every wet spot is a leak. The brief says moisture condensing in an attic that is not properly ventilated can produce what it calls false leaks. Conshohocken’s re-roofing addendum sets the borough’s minimum attic ventilation at 1 square foot of net free vent area for every 150 square feet of attic, or 1 for every 300 when at least half the vent area is high in the attic, at least 3 feet above the eave vents, with the rest at the eaves, or when the ceiling has a vapor barrier on its warm side.

After a storm

NRCA suggests an extra inspection after severe weather. The weather guide gives the local record of hail reports and high wind gusts. After a hailstorm, look from the ground for the items on the list above. For insurance after storm damage, see the guide to storm damage claims.

What a home inspection covers

Pennsylvania’s Home Inspection Law, Chapter 75 of Title 68, defines a home inspection as a noninvasive visual examination of a house’s systems and components, designed to find material defects, done for a fee in connection with a sale. The law says an examination of a single system, such as a roof, is not a home inspection under its terms.

The law sets several protections for buyers:

• When a sales agreement gives the buyer the right to an inspection, the inspection has to be done by a full member in good standing of a national home inspection association, or by a licensed engineer or architect, or under the supervision of a full member who signs the report.
• The written report must describe any material defects and include any recommendation to bring in experts to judge the extent of a defect and what should be done about it.
• An inspector, or the inspector’s employer, may not charge to repair a house it has inspected within the previous 12 months, with exceptions for radon and wood-destroying insects.
• An inspector must carry errors and omissions and general liability insurance of at least $100,000 per occurrence and $500,000 in total.
• A lawsuit over a home inspection report must be filed within one year after the report is delivered.

The law also says courts judging an inspector’s care should consider the standards of practice of national home inspector associations. InterNACHI, the International Association of Certified Home Inspectors, publishes standards of practice for its members. For the roof, its standard says the inspector shall inspect from ground level or from the eaves:

• the roof covering;
• the gutters and downspouts;
• vents, flashing, skylights, the chimney and other penetrations; and
• the general structure of the roof, from readily accessible panels, doors or stairs.

The inspector must describe the type of roof covering and report any observed signs of active leaks as needing correction. InterNACHI’s standard says the inspector is not required to walk on the roof, predict how long it will last, remove snow or debris that blocks the view, run a water test, warrant the roof or confirm that the roofing was fastened and installed properly. It also says a component near or past the end of its normal life is not, by itself, a material defect.

What to settle before you buy or replace

An inspection report that flags the roof leaves several points for a roofer to answer. Conshohocken’s re-roofing addendum asks about most of them, and its form works as a checklist for any house in the area:

The guide to roofing materials gives service-life estimates to compare against the roof’s age, and the guide to the housing stock covers how to look for a past re-roofing permit in Conshohocken.