5 Things You Don’t Know About Metal Roofing (or “tin rufs” to some of us)
I have seen people ripped off by traveling workers offering a hail proof metal roof for the same price, or cheaper than their asphalt shingles. They will screw down these metal panels directly over the asphalt shingles, or over some batten boards that have been fastened over the shingles. And the reasoning behind otherwise intelligent homeowners convincing themselves that this is a good idea is: the price is “too good to pass up” and “metal roofs are hail resistant”.
These days, since Oklahoma has the 2nd loosest consumer protection when it comes to the roofing industry, many “contractors” are broadening their horizons into alternative roofing materials, i.e. metal roofing. After all, how hard can it be to screw down some metal panels? They don’t bother to educate themselves first, or get certified with the products (especially in Oklahoma or Texas where they are not required to). The only way for a homeowner to protect their home is to know a few things about these metal roofs, before letting a novice metal installer butcher their roof. After all, the roof costs 10% of the home’s value and is supposed to keep the rain out of the other 90% of it.
1. R-panel roofing should never be installed on a residential home. It is the wrong type of roof for a living space. If you ask any roof shingle installer, “is it ok to drive nails over the shingles and have them exposed?”, they will all say “NO WAY! That will eventually cause a leak.” So, why then would it be ok to have metal panels with hundreds of exposed fasteners? If the fasteners are a little too loose, they will leak. If they are a little too tight, they will leak. If they are driven a little off angle,
People say that they want a metal roof because it is hail resistant (pay special attention to #2&5), but if we are honest with ourselves, we will admit that R-panel is the cheapest type of metal roofing, and that is why it is attractive.
2. Thickness affects price. Metal roofing is measured by the gauge. The lower the gauge number, the thicker the metal (I know it seems backward, but I didn’t invent the standard). The most common roof gauges are 29, 26, and 24. And 29-gauge is what the unscrupulous roof scammers are peddling at their “amazingly low price”. Now, to add some perspective: a soda can is a 37 gauge and a car hood is around a 20 gauge. Why would you buy a metal roof just slightly thicker than a Dr. Pepper can (with a bunch of screws sticking out of it)? And what makes anyone believe that 1.5” hail can damage the hood of a car, but not a metal roof made of a thinner gauge metal?
3. Lower wind resistance! People in Oklahoma are sick of hail, and hail damaged roofs, and I get that, but the number one cause of roof damage is WIND. I repeat, wind damage is the number one enemy of your roof system. Oklahomans are just so used to the high winds that it doesn’t register as a big deal.
Last year my wife and I took a trip to New York, and the first conversation we had with a New Yorker was with the cabdriver on the ride from the airport. “Where are you from”, and “how’s the weather there”, seems to be the standard small talk. After we described tornado sirens, shelters, and the 90 mile per hour windstorm that Edmond and North OKC recently had, he thought we were out of our minds for living in the mid-west. Looking back, I thought he was a big sissy, but it dawned on me that we are just used to it.
My point is, most metal roofing panels are rated for up to 90mph winds, that’s it. A properly installed dimensional shingle roof is 130mph. Why would someone take such a downgrade? Because they are fed bad information, that’s why.
A word of caution from my experience, when wind damages a properly installed dimensional shingle roof, it will usually flip a few tabs (at around 110-130mph). When wind damages an R-panel roof, it will rip off the entire panels (at around 85-105mph, and it take even less force if the panels are installed straight over shingles). That will equal another insurance claim, which most people are trying to avoid by getting a metal roof.
4. Expansion and contraction. When incompetent roofers install a cheap, higher gauge, metal roof with exposed fasteners, they will always forget to account for expansion and contraction of the metal. The actual movement of the roof panels as they heat up and cool off is quite minimal in lengths less than 25-30 feet, but multiply the minor push-pull effect on the exposed fasteners over 3, 5, or 7 years and your family might as well start a death pool for you roof.
5. Functional damage. While it is true that most metal panels have qualified for the Class 4 rating from Underwriters Laboratories “UL 2218” test standard for “Impact Resistance of Roofing Materials”. This only proves that the middle of the panel did not break when a 2” steel ball was dropped on it from about 20’ in the air. The problem with this arises when the hail hits a one of the many metal seams, or one of the hundreds of exposed fasteners, then functional damage to the roof will occur, and a small opening or crease will be created allowing moisture to invade under the roof system; and those leaks are very hard to pinpoint. That will equal another insurance claim, which most people are trying to avoid by getting a metal roof.
In my opinion, based on my experience, Standing seam panels, or metal shingles are the only way to go when considering metal roofing for your home. Click here to read a previous article on Stone Coated Steel Roof Panels. Stay tuned for our take on Standing Seem Roofing for your home.