At some point in time, your home is going to need a new roof.
Whether the reasons for this expenditure are due to your present roofing showing signs of severe wear and tear, or simply because you ran out of pails this past weekend in a frantic attempt to control the drips leaking down from the ceiling, eventually, roofs need replacing.
Essentially, you’ll have two choices, them being steel or fiberglass asphalt shingles.
There are rubberized and composite type shingles out there, but they’re considerably more expensive, and are not so readily available locally. And, with this column being very much pro-local shopping, along with encouraging the pro-local hiring of tradespersons, we won’t be considering these products.
What about cedar shake roofing? Real, cedar shake shingles, whether they be hand-split (varying texture) or rough sawn (more uniform texture) look terrific, especially on a stone or colonial styled home. Unfortunately, and regardless of their traditional good looks, cedar shakes are probably not the best choice for our climate zone. Simply put, our climate is too wet, too cloudy, and we have far too many trees casting shadows over our roofs. So, with these cedar roofs rarely achieving even relative dryness, you can pretty well expect algae and mold growth within a year or two. Combine this with the three to four freeze and thaw sessions we experience over the course of a winter, and you’ve got all the reasons as to why putting a wood product on your roof is a bad idea.
If your budget has the wiggle room to accept the price of cedar shakes, then you should be considering a steel shingle. However, before choosing between steel and fiberglass shingles, let’s examine what’s underneath your existing roofing.
In the olden days, with ‘olden’ referring to the days of organic shingles, and otherwise recognized as the days when Canadian based teams won Stanley cups, shingles could be layered up to three thicknesses deep. Plus, it was very common to carefully remove the 1×6 planks of wood that served to form the foundation walls, once the concrete dried of course, then reuse this lumber as roof sheeting. When it came to steel roof application, the support, or underlay strategy back in those days had the installer simply installing lengths of 1×4 rough strapping at every 16 inches on-center over the roof trusses, and that was it.
Were these install strategies misguided or reckless? Not necessarily. They were simply justified practices in accordance with what was known and understood during those times, just like bloodletting was the treatment of choice in the 1700’s for those who had fallen ill with anything from laryngitis to an upset stomach.
Sometimes, even our most intelligent people get it wrong.
Today, we understand that both fiberglass asphalt shingles and steel roofing panels require stability. When things move, nails and screws will loosen. When that happens, the next Nor’easter wind will be forcing shingle tabs up, and peeling back your steel roofing panels like the skin on a ripe banana.
The answer to providing a stable roofing underlay is plywood. So, if you’re building a new home, addition, or garage, whether the finished roofing product is fiberglass shingles, or steel roofing, the underlay material must be plywood.
Can fiberglass shingles or steel roofing be installed over an existing shingled roof? Although this strategy will save you dumping fees, stacking one roof over another is going to cause a number of problems. One, the average roof requires about 65 bundles of shingles, which equals about 4600 pounds, or the weight of a 1965 Pontiac Parisienne. So, with every layer of shingles representing one 1965 Pontiac Parisienne left unnecessarily on your rooftop, you can see how this practice could eventually overwhelm an aging truss structure. Plus, a layer or two of shingles will have a certain sponginess to it, preventing the installer from effectively securing a new shingle tab, or tightening down the screws on steel roofing.
Next week, more on roofing.