Metal roofing how to..metal roofing details
Should I tear off the existing roof shingle ?
Ask yourself, has this roof been leaking for a while? If the answer is yes, then you could have some roof deck damage such as rotten boards or plywood that you may want to replace before installing a new metal roof. If you only have one layer of asphalt shingle and the deck seems to be in good shape than you can leave it in place and roof over top if you are planning to install an interlocking metal shingle roof. If you want to install standing seam roof, then you may want to do a full tear off, because asphalt shingle could cause unequal lines and dents in standing seam panels overtime.
The Tear Off :
The tear off is going to be the messiest and most physical part of all work especially if you have more than 1 layer of shingle. I have had the pleasure to strip as many as four layers of shingle on one of the roofs we worked on, and the best part was that there was no tar paper underneath, which caused asphalt to melt into and adhere to the roof deck. Needless to say it took forever to strip that roof, but it was worth it for the homeowner because, there was some serious roofing deck damage that needed to be addressed. Also, it is generally not recommended to have over two layers of roofing material on any roof and many States have regulations specifying the maximum number of roofing shingle layers that a roof may have.
If you have decided to do a tear off, you will need following tools and equipment :
- Stripping tool / shovel
- Good Pair of working Gloves
- Tarp of sufficient length
- Respirator or Face Cover if you are sensitive to exessive dust
- 5 to 7 strong, young men to do the work.
- YOU as the supervisor if you decide to undertake this mission yourself.
Most of our work is either new construction or a new metal roof over a single layer of shingles. When we encounter a roof with more than one layer of shingles, it is imperative that the old roofing be removed, even if the local code does NOT require removal. The additional weight of more than one layer of shingles PLUS the new metal roof makes the load of most framing too much to handle.
First, you must order the materials. We only use 26 gauge metal which is commercial grade metal. These panels are customized on the job and require EXACT measurements, so get a good tape and know how to read it. This process is similar to designing a jig saw puzzle yourself….you must keep good records of the lengths and have them written on your legal pad. We know what we are doing, so we combine several short runs of say 3 to 5 feet into one panel that is 20 feet in length. You, as a handy person, should omit this step. ONLY order the panels in the lengths the job demands.
OK, we have ordered the roofing panels from the plant…we included all flashings, screws, vent stacks, starter strips, ridge caps, and chimney flashing. This big truck arrives with all the materials, so we have to help unload the materials in the reverse order in which they were loaded. This requires ‘sorting’ of the different lengths according to your legal pad diagram. The worst thing that can happen is to install some panels in an area other than the one we anticipated.
New 1×4′s are mechanically attached to the underlying rafters. We know where they are cause we are professionals, you might have to get out your thinking cap and measure from the edge of the roof, marking 16 inches on CENTER…the first screw or nail you drive through the 1×4 will tell you if you are on a rafter or not. You MUST attach these strips into the RAFTERS…no excuses here. The strips are installed on 2 foot centers, with strips along the eaves, and around any vents to be flashed or chimney flashed. As part of this process, the ridge of the roof is opened up by cutting and removing an area comprising a minimum of 6″ so that we have a ridge vent allowing air to circulate and get out. This is one step that some contractors omit, yet it is one of the most energy saving step, so make sure you or your guys do this.
Once the strips are attached in the area to be roofed, we install the starter strips and the wall flashing strips…these will be ‘under’ the installed roofing panels. Get your first roofing panel to be installed along the edge of your roof area to be roofed. It is mandatory that this panel be installed perfectly…square and square…as the other panels will be installed off of this first panel. Here is a video showing you how to roof using metal roofing.
metal roofing how to
The panels are attached with color matching screws provided by the manufacturer. Additionally, on low slope roof systems ( systems with less than 3 in ‘drop’ every 12″ ), a thread of the sealing tape will be attached to the panels at the overlapping seams, this avoids any ‘run back’ during heavy rains or snow accumulation. Continue installing new metal panels, checking to be sure you are ‘square and square’…no crooked panels allowed. NONE!
Once you have the metal panels installed, you will go back and install any vent stacks and counter flashing on the roof. You are making an ‘umbrella’ for the home, so think in those terms and imagine how the rain will drain from the roof. Additionally, we install a matching color flashing strip on the front edge of the roof. This is a ‘just because’ since it doesn’t add to the water protection, yet improves the street appearance of the home.
check on youtube for additionally videos.
metal roofing how to
video on standing seam metal roofing