What can a homeowner do to have their asphalt shingles last at least long enough to see their children through college, thereby avoiding the financial double whammy of tuition and having to pay for three pallets of roofing products?
Let’s start with the installer.
Besides getting references from their previous customers and your local building supply centre, look for a few minimum standards, like someone who has his own vehicle, and a trailer for handling scrapped materials. Plus, their pickup should have permanent lettering on the door, prominently displaying the company name or logo.
Avoid the guy whose accreditation required him properly levelling one of those 12”x18” magnetic mats on the driver’s side door. These guys are most easily recognized by a “Frank’s Roofing-free estimates” type of mat, stuck to the door panel of a vehicle that looks like it just escaped the wrecking yard cruncher.
Upon inspection of this fellow’s vehicle, it wouldn’t be surprising to find other magnetic-mat specialties, such as “Frank’s Pizza Delivery,”, or “Frank’s no-leak plumbing,” which to his credit, demonstrates a work ethic and versatility, but may be further proof of this fellow’s homeschooled level of accreditation.
Next, today’s Fiberglas shingles require stability, which means following a pretty straight forward set of directives regarding shingle installation, shingle underlayment, and attic ventilation.
There are basically two ways or manner of pose, regarding asphalt shingles. One is the regular four-nail per tab installation, where four nails are placed at the top of the shingle tab, with the bottom of the tab being held down by means of a sticky glue-strip (found under each shingle) that gets engaged by heat generated from the sun. The second method is the six-nail-per-tab/plastic cement installation strategy, used in high wind areas, or during cold-weather (below 0 C) installations.
Windy areas generate dust, with this dust getting underneath the shingle tabs as they’re being installed, adhering to sticky glue-strips. When the sticky strips get covered with dust, the shingle tabs forfeit the bottom sticking mechanism that prevents them from lifting up. Other than dust, cold temperatures will also prevent the sticky strips from properly engaging. The six top nails, as opposed to four, and the dabs of plastic cement placed under each shingle tab, are just extra insurance against shingle lift.
So, if looking out your window has you seeing open field, or river. Or, the frost on the window is preventing you from seeing clearly outdoors regardless, you would be wise to request installation manner No. 2 from your roofer.
Next, shingle underlayment.
Although the installation procedures for Fiberglas shingles do permit you to install your shingles over an existing shingle roof (to a max of three layers) and/or over a boarded roof of 1×6 planks, these are not good ideas.
An average roof requires about 60 bundles of shingles, which weighs about 4,200 pounds, equivalent to one 1986 Pontiac Parisienne, or the combined weight of the Montreal Canadiens playing personnel.
Your home requires one layer of shingles, with every layer underneath unnecessarily burdening your trusses with the equivalent of one automobile parked on your roof. So, removing your old shingles may cost you a few hundred bucks in dumping fees, but it’ll lessen the stress load on your trusses, allow you to fix or remedy any roof underlay issues, and make for a better install overall.
Boarded roofs were popular about 40-50 years ago when contractors were forming their own foundations with 1×6 spruce, then removing these planks once the cement dried and installing them on the roof, an efficient use of materials which worked fine as an underlay for the very flexible, organic (paper felt based) shingles of the day.
However, today’s fiberglass shingles are much more rigid, especially during the colder months, and will better survive the test of time if installed over plywood.
So, if you own a plank roof, be sure to install a 3/8-inch spruce plywood over the planking.
Next week: ventilating your attic.