by Michael Chotiner of The Home Depot
Roof assessments are among the most valuable observations a home inspector can provide for a prospective home buyer in the pre-purchase inspection report. Authoritative judgments about if and when a roof may need replacement can have a significant impact on price negotiations and/or the buyer’s planning.
The primary reasons for replacing a shingle roof include:
Age. Standard-weight 3-tab shingles that have been on a roof for 15 to 20 years may be due for replacement. Heavier laminated shingles generally have a somewhat longer service life.
The roof slope is not steep enough. Asphalt shingles are not recommended for roofs with slopes of less than 4:12 (the ratio of inches of incline to inches of run); they should be replaced with an appropriate membrane.
Generalized deterioration. A large number of shingles that show defects, such as cracking, curling, and/or eroded mineral surface, are likely to lead to roof failure.
Widespread cosmetic defects may be attributable to manufacturing defects if they're covered by the manufacturer’s warranty.
Failure may be attributable to improper or inadequate installation of the roof-covering materials (including the underlayment), such as leaking, and/or widespread, frequent shingle blow-off during high winds and storms.
Storm damage over wide areas is likely to lead to leaking and/or deterioration of the substrate.
Re-Roof or Repair?
It may make more sense to address leaks and localized cosmetic issues on a spot-repair basis if the roof isn’t too old and replacement costs aren’t adequately covered by the warranty. At the same time, a new roof may be a better financial option than annual repair bills as new problems continue to arise.
If the homeowner chooses re-roofing, a contractor may offer to provide a quote for replacing the gutters and downspouts along with their re-roofing proposal. These projects can go hand in hand, but they don’t necessarily have to.
What Homeowners Should Know About Gutters and Downspouts
As with roofing, the primary reason for replacing gutters and other drainage accessories is that they are damaged beyond repair. Another good reason is that the existing roof drainage system was not properly designed--for example, if the troughs and downspouts are too small for the volume of runoff from the roof.
Most roof drainage systems that have been on a home for more than a few years show signs of deterioration and/or deteriorating functionality. Common signs include:
twisted gutters (their profile is distorted);
popping gutter fasteners, sagging and twisted brackets, and gaps between the fascia and the back of troughs;
water frequently spills over the edges;
the pitch of gutters is not directing water to the downspouts;
leaking is occurring from gutter end caps and other joints;
there's leaking at the joints at downspouts;
the gutters are discolored;
their finish is damaged;
there is rust or other signs of oxidation; and
there's saturated, eroded or collapsing soil within 5 feet of foundation walls.
None of the issues listed above—either by themselves or in combination with others—is necessarily an indication for gutter replacement. The best ways to approach repairs and choosing who should perform them may depend on the material the gutters are fashioned from. And, of course, it’s prudent to do a little troubleshooting to determine the cause of any particular problem, if possible.
Specialists Recommended for Steel and Copper Gutter Installation
When the gutters in question are made from steel or copper—as they are on many older, upscale houses—it’s best to consult a sheet metal contractor with the experience, tools and equipment for making appropriate repairs and/or replacement of sections. Where steel gutters show rust spots, the rust can usually be neutralized and the gutter repainted, with little loss of strength or rigidity.
More Homeowner Tips
Sagging gutters are most often easily repaired by replacing the original fasteners with better ones. Gutter screws hold much better than smooth spikes, and various brackets can be added to beef up a weakened fastening system. A sagging gutter can usually be straightened and set back in place at an effective drainage pitch with improved fasteners, as long as the fascia is sound. Gutters age over time with humidity and temperature swings, just as a roof’s shingles do, so keep them clean and unclogged to reduce extra weight in them.
For conventional open troughs, clean leaves and other debris at least twice annually, in spring and in fall. Check and adjust the fasteners while you’re at it.
Certain brands of one-piece gutters with formed-in leaf guards have good track records. They come with a lifetime warranty and cost two to three times more than conventional gutters. This type must be installed by manufacturer-trained technicians and are not generally available through roofing contractors.
Sizing Gutters and Downspouts
Seepage inside basement walls, a depression in the soil directly below the gutter, and eroded or collapsing soil within 5 feet of the foundation walls can indicate issues that may require redesign or replacement of the roof drainage system.
Some of the causes include:
The gutters and downspouts may be too small to handle the volume of runoff from a broad, steeply pitched roof.
The downspouts may be incorrectly placed, or may be too few in number for the size of the roof.
The downspout outlets may not be extended far enough away from the foundation.
InterNACHI member Bud Coburn of Action Plus Home Inspections offers an informative tutorial on his website about how to properly size gutters and downspouts, as well as other aspects of a roof-drainage system design. Visit https://actionplushi.wordpress.com/2013/01/28/how-to-size-gutters-and-downspouts/ to read more.
If an inspector’s observations about roofing and roof drainage systems point toward replacement, the client may be interested in reading The Best Practices Guide to Residential Construction by Steven Bliss, which lists a number of questions to consider when evaluating a roof warranty:
Is the warranty prorated from the date of installation, or is there an introductory term of five to 10 years when the full value can be recovered?
How long is the warranty valid against wind damage, algae growth, or other issues?
Does the warranty cover a portion of the labor costs of tear-off, disposal and installation, or does it cover materials only?
Is the warranty transferable?
And perhaps most importantly: Does the manufacturer have a strong reputation for warranty service in the local area?
In addition to the terms of a manufacturer’s warranty, homeowners should evaluate their installer's warranty against defects in workmanship and adherence to code standards.