Most homeowners don’t know much about the condition or composition of the roof above their heads, unless there’s a leak and they need it repaired. But armed with some basic knowledge, a prepared homeowner can know what to expect when reviewing quotes from contractors for a roof replacement. Many roofing contractors will provide plenty of answers to roofing FAQs on their website. But here are some additional tips for what to expect from your asphalt shingle roof replacement or new roofing installation, including price range, warranty, and components of a complete roofing system that should be replaced and installed anew.
First, the Components of a Complete Asphalt Shingle Roofing System
Much more goes into a roof than just the outermost layer of asphalt shingles. A roof is actually a system of many different barriers that all work together to protect your home from water and weather. First is the roofdeck, which is composed of plywood or OSB (oriented strand board) sheathing. This needs to be dry and free of rot in order for the roofing structure to be considered intact, and a roof replacement scope of work should include any necessary repairs to the plywood/OSB roof decking.
Next comes underlayment: either common roofing felt paper or newer synthetic versions. This paper acts as a vapor barrier to protect your roof deck from any water that may penetrate the layer of shingles. Some roofers say it is not needed, but it is a good idea to provide this extra protection because plywood and OSB sheathing are not supposed to get wet. When it does, it will swell and become disformed, and eventually rot.
Valleys and eaves are particularly prone to ice and snow buildup as well as increased water runoff, so these vulnerable areas are best protected by additional underlayments. A polymer-modified bitumen underlayment in addition to common roofing felt or synthetic paper is often installed in the valleys and eaves, under the shingles, to help protect against ice and water buildup. Fittingly, this product is called “Ice-and-Water shield”, with different manufacturers using different brand names.
Many flashing systems ought to be included in a full roof replacement scope of work. Some roofers will often skip replacing the existing flashing, in order to cut corners and save on costs. You should check your quote to make sure that your contractor is planning on replacing chimney-flashing, step- and counter-flashing where the roof meets any walls, vent pipe boots and jacks, etc. The most common type of flashing is known as “drip edge”, which is a thin F-shaped piece of metal that is installed, obviously, around the edge of the roof and helps control the flow of water into your gutter systems. A full roof replacement should include all new flashings, because one failed piece of flashing can ruin the entire new roof.
Your ridge vent and shingle-over-ridge cap system is also very important. Depending on how your home is built, there is often a vent cut in the “peak” or ridge of your roof in order to facilitate air ventilation. An improperly ventilated attic can cause warping and buckling of your roof deck sheathing, which will ultimately cause the roof to fail prematurely, not to mention it will look awful when your roof starts to become wavy and uneven. Some homes have eave vents or gable vents in addition to or instead of a ridge vent. Make sure your roofing contractor knows what is needed for your particular home and will install the appropriate ventilation. If your home is like most, this will include a vinyl or aluminum ridge vent with asphalt shingle ridge caps that cover it for an enhanced aesthetic look.
Pricing Your Asphalt Shingle Roof Replacement Service
Most full roofing system installations will cost anywhere from $300 to $500 per square. A roofing square is 100 square feet, so that is $3 to $5 per square foot. This should include the complete tear-off and demolition labor, haul and dump fees, installation of all components, and an architectural asphalt shingle with a limited lifetime warranty. Manufacturers that offer lifetime warranties include IKO, CertainTeed, GAF, Owens Corning, and more.
Lifetime Warranty for Architectural Asphalt Shingle Roofing Products
GAF roofing manufacturers are the leading marketers of the “lifetime roofing system”. It’s sort of a marketing gimmick in the sense that it really only means that you are warrantied against manufacturer defects that cause roofing failures and leaks. These are so uncommon that it is very unlikely that any roofing problems you face will be covered under this warranty. If something goes wrong with your roof, it is much more likely that your home has suffered some sort of storm damage that can be covered by insurance. If not that, then perhaps your roof was not installed properly. This is why the most important decision you can make in terms of warranty and coverage is to hire a reputable roofing contractor who will stand behind their work for years, and even decades, to come. A good roofer will install a roof correctly and you therefore should not have any problems with your roof for at least 20 or 30 years after installation.