The home pictured above was designed by an architect and built by an engineer. To give you an idea of the care with which the house was built, the contractor used 2×10 rafters on 16″ centers (it’s rare to find houses with rafters any bigger than 2x6s)! It originally had 3-tab asphalt shingles on it. After roughly 15 years, the shingles were getting worn out. The homeowner decided to invest some money and get a lasting roof that would help accent the architectural flair of the house. Caldwell’s Roofing thinks it was a good decision. The horizontal lines of the siding, the geometry and symmetry of the home’s design, and the darker color of the paint job, play nicely with the straight, vertical lines of the bright new metal roofing.
Out with the Old – Removing the Shingles and Prepping the Decking Substrate
Removing shingles from a steep-slope roof is a dangerous task. Caldwell’s Roofing was careful to follow OSHA requirements of proper harnesses and anchor points, hardhats, as well as having a designated safety monitor while doing their work. They also took the shingles to a recycling location, where they will be reused in road-making.
Since 1/2″ OSB (“Oriented Strand Board”) had been used for the original decking of the property, the homeowner wanted to install some 1/2″ CDX plywood on top of the OSB to create a better substrate for the screws of the metal roofing to be fastened to. Although adding significantly to the price of the project, Caldwell’s Roofing thinks this also was a wise choice for the long term. CDX or other forms of plywood exhibit better retention of screws and are a better roof decking material in general, as stated by GAF, the NRCA, and other roofing organizations. After the decking was installed, GAF’s StormGuard underlayment product was rolled out and stuck onto the new decking. You can see all stages of this process going on in the picture below. The StormGuard is a bituminous product that withstands the high temperatures a metal roof sees and that helps to waterproof fasteners that go through it. In this way, it’s like a second layer of defense against water intrusion, even though standing seam metal roofing is already an incredibly water-proof roofing choice. Additionally, the underlayment served to protect the house while the metal roof was being installed, since metal roofing is a much slower installation than shingle roofing (this project took about 2 months from start to finish, but was a large house, with a steeply-pitched roof).
In with the New – Standing Seam Metal Roofing Installation
On this project, 26-gage, galvanized, “Steel-Lok” profile standing seam metal roofing was used. It was fastened with 1 1/2″-long pancake-head screws (except on the exposed eaves and rakes, where 1″ screws were used so as not to protrude through) through the punched out slots on the sides (“flanges”) of the panels. The beautiful thing about standing seam metal roofing (in contrast to other metal roofing profiles such as 5V-Crimp or Eagle Rib) is that the fasteners end up being hidden, both from view, and from water. What this means is that the roof is guaranteed to last longer and look better. In the photo below, a worker has installed a heat-resistant EPDM boot around a gas water heater exhaust pipe stack, and is cutting the metal boot to fit the profile of the metal roof so as to slide on top and “hide” the unsightly red color. EPDM boots are the material of choice for waterproofing your pipe penetrations on a roof when doing metal roofing, but they don’t look all that great (imagine a gear-shifter in a vehicle, and that’s about what they look like). Notwithstanding, they do a great job of keeping water out of a troublesome location, and they stand the elements fairly well.
There are more commercially-used standing seam metal roofing profiles that incorporate a hand or machine “seamer” to join one edge of a panel to the opposite edge of the next panel, but this particular profile “Steel-Lok” can be “clicked” together by mashing your foot on top of it, by pressing firmly with your hand, or by beating with the soft handle of a hammer. Believe it or not, running the panels is not all that difficult – it’s the preparation items like drip edge, and the flashing and finishing details (like ridge cap) that take the longest, proportionally. It’s tempting to take short-cuts on flashing areas, but those are going to be the weak points of a standing seam metal roof, and are the areas most critical to “get right.” This roof had two long (nearly 30′ each!) sidewall transitions. Caldwell’s Roofing cut the siding back roughly 6″ from the roof, installed sidewall flashing to reach under the existing siding, and then installed a rough-cut cedar 2×4 and caulked/painted it to give the new transition a finished look, as seen below.
The design of this property was basically 3 gable roofs with a couple of shed roofs on the body of the house. That meant there were 6 gable ends that needed to be addressed. Caldwell’s Roofing made the bent triangular gable covers to make sure any wind-driven rain that got in would be diverted back off the roof, rather than under the metal panels. Visible in the photo below is one such gable end cap, as well as the perimeter run of the mastic and Z-bar that must be in-place to attach the ridge cap to.
After installing the ridge cap and fastening them with stainless steel rivets, the roof was finished. Here are a couple of photos of the completed project.