3 Ways Your Roofing Contractor Can Void Your Roof Warranty

Many homeowners get peace of mind knowing that they have a long warranty on the roofing products installed on their home. Most shingles now a days even come with a limited lifetime warranty instead of the old 30-year warranty. However, most homeowners don’t know that there are things a roofing contractor can do (or neglect to do) that will void the manufacturer warranty.

Improper Ventilation

Image: Damage done from improper ventilation

Your roofing contractor should know enough about attic ventilation to properly vent your attic. The requirement by the  Building Code (2009) is 1 square foot of ventilation for every 300 square feet of attic floor space. So if you have a home that is 1500 sq. ft. you will need approximately 5 sq. ft (720 sq. in.) of ventilation, split between intake and exhaust vents. Intake vents are usually in your soffits, while exhaust vents are at the top of the roof.

In the example above, you should have 15 roof louvers (can vents) with a NFA (net free area) of 50 sq. in. each. Alternatively you could go with a ridgevent like ShingleVent II (what we use), in which case you’d only need 40′ (or 10 pieces) of ridgeventing.

At New Heights Roofing we recommend increasing ventilation to 1:150 ratio from 1:300 since it will greatly increase the air flow in your attic, keeping your home cooler in the summer and helping to prevent ice dams in the winter. To do this without covering your roof with roof louvers, we recommend a concealed, continuous ridgevent like ShingleVent II.

If your home is not properly ventilated and your shingles fail early, they won’t be covered by the manufacturer’s lifetime warranty. Without proper ventilation your warranty will be reduced to 10 years, with no SureStart protection.

Installing Over Non-Approved Roof Decking

Damage found during sheating inspection

Image: Damage found during sheating inspection

Your roofing contractor should be able to tell you what type of decking your home has and if it is an approved deck to install shingles on. Examples of fully approved decking are plywood (minimum 3/8″), OSB (minimum 7/16″) and wood board sheathing (minimum 1″). If the wood board sheathing is large (1×6, 1×8, 1×10, or 1×12) it may cause buckling in the shingles so extra precautions should be taken. It may be necessary to install new 4′x8′ sheets of plywood to provide a solid, smooth surface to attach shingles to.

Loadmaster and Homasote roof decking are “permission-required” decks and must be installed according to manufacturer instructions and may require special fasteners to meet the warranty requirements. Other roof decks like Cementitious wood fiber board, gypsum, and insulation boards are not approved and require an approved decking be installed over them. These decks are not common among residential homes.

If there is existing water damage, dry rot, or any other damage done to your sheathing the shingles installed on top of it will not be covered by the manufacturer warranty. An example of this is an undiscovered leak where the wood is not repaired before reroof. If that piece of plywood fails in the future, the shingles installed over it will not be covered by the warranty.

Another way a roofing contractor may void your warranty is by not prepping the roof decking properly after tearing off an existing roof. If there are existing nails sticking up that poke through the shingles, the damage will not be covered by the manufacturer warranty.

To prevent any of these scenarios, we recommend tearing off all existing roofing material (including the old felt paper) so we can get a good look at the roof deck and inspect it thoroughly for damage. We also take our time and scour the roof deck for existing nails that were left behind and either pound them into the decking or remove them completely. New Heights Roofing takes every extra precaution to be sure our customers will never have a problem with their roof in the years ahead.

Improper Fastening

Proper fastening of shingles is vital

Image: Proper fastening of shingles is vital

Improper fastening is one of the most common causes of shingle failure, and is not covered by the manufacturer warranty. Companies with a great warranty like CertainTeed offer a 110 mph wind warranty (can be upgraded to 130 mph by using proper starter and ridge cap) for the first 15 years of shingle life.

However, if your shingles blow off due to improper fastening, it will be up to you to go after your roofing contractor or pay for the repair out of pocket. There are several ways that fastening will void your shingle warranty:

  1. Over-driven nails tear through the shingle and make it very easy for the shingle to be pulled off by gusts of wind.
  2. Under-driven nails will hold up the shingle above, preventing it from properly sealing down to the shingle below. This can let dust in which will prevent the sealant from ever activating, and also allows wind to catch the shingle and pull it off.
  3. Nails that are driven crooked into the shingle cut into the shingle on one side of the nail, while the other side holds up the shingle above. These two things combined makes for a perfect opportunity for shingles to catch the wind and fly off your roof.
  4. Nails that are too short. Nails must be long enough to penetrate through the shingle and all the way through the sheathing. If the roof decking is thick, nails must penetrate up to 3/4″ into the wood.
  5. Not enough nails – Each type of shingle requires a certain number of nails to be used per shingle, the average is 4 nails placed evenly.
  6. Improper placement of fasteners – Each type of shingle also has a “nail line” where nails are required to be placed to achieve the designed performance. If the nail line is missed, then blow-offs are much more likely to occur and are not covered by the manufacturer warranty.

One of the biggest causes of the above mistakes happening is roofing contractors that are rushing to get the job done. Using a pneumatic nailer too quickly can cause the installer to improperly fasten shingles and not even realize it.

Because of these things, we at New Heights Roofing always take our time to ensure every shingle is installed according to specification. Staples are never used, only approved, galvanized, wide-head roofing nails. We also install each shingle with 6 nails instead of the required 4 (commonly referred to as “storm nailing”). This will ensure that blow-offs are never a problem for our customers.¬†We never rush or take shortcuts to finish a job faster. We believe our customers want a higher quality installation they won’t have to worry about, rather than their roof being finished a day or two sooner.

As you can see there are lots of little things that can happen that can potentially void your shingle warranty and not give you the protection you may think you’re getting. That’s why we always recommend hiring a company you trust rather than the lowest bidder. If you’re not sure about the contractor’s ability to install everything 100% correctly, don’t hire them. Your roof is a vital part of your home, don’t be afraid to invest a little more to find a reputable contractor that will do the job right (the first time).

If you have questions about your roof and would like a free inspection, call 1-855-ROOF-ART today to get one scheduled.

If you need a roofer in Post Falls or the surrounding areas, let us come visit and answer all your questions.

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