Metal roofing has long been used in commercial and farming for protecting buildings but in the past 15 years or so metal roofing is finding its way into residential communities because it is easy to care for, has a long life and the added features of fire prevention and the ability to collect water from rainfall.
If you are interested in installing a standing seam metal roof system on your home we will cover some of the steps required to complete the job.
Remember that each manufacture has different recommendations and if you are purchasing one of the newer decorative design panned systems your install method may change dramatically.
Should you remove the old roof shingles?
This is one of the first considerations because tarring off your current roof can be a lengthy and difficult process. Although it is not really technical and is often completed with a garden fork and a lot of sweat it can get a little dangerous because it takes effort and you are up on a roof.
If your roof is not leaking and you only have one layer of shingles then leaving them on is not a problem. If you do have leaks or if you have more then one layer then removing shingles will be required and possibly repairing the deck with new half inch plywood.
If you are removing the shingles then you should put a water barrier membrane on the first six feet up from the gutters on the eves and in your valleys. Areas around fireplace chimneys should be sealed well and flashed with manufacturer recommended flashing.
Starting the Install
Fasteners are screws and clips that are provided by the manufacturer and have gaskets washers to seal holes. It is recommended you use them and don’t skimp.
Begin by installing your Eave Flashing where your gutters mount to your facia. It extends about six inches up onto the roof and includes a drip edge to allow water from the roof to run into your gutter.
Then install your gable flashing that runs up the side of your roof to the peak.
It is extremely important that your Gable And Eave flashing are installed square to each other and to the roof. Take proper measurements to make sure they are square and use a piece of roofing to make sure that the flashing does not bow while you are securing it to the roof.
Now you can begin installing your metal roofing sheets.
You should allow enough room at the peak to provide for a ridge vent and make sure the pieces extend slightly past the Eave flashing at your gutter so water will drip into your gutter.
All of your materials should be ordered to length but you can cut to make adjustments on site with a circular saw and a metal cutting blade. Using snips or a metal cutting break can work in some instances but you are likely to bend the roof sheets with a break.
Silicone or other sealers are not usually needed when installing the roof sheets. Instead of caulking the ends you use a rubber gasket strip called a Closure that is made specifically for the profile of your roof sheets.
When installing near valleys you install the valley flashing first and then extend the roof sheeting up to about 4 inches from the center of the valley to provide for movement. Do not screw into the ends instead let about 6 inches of the roof sheeting be free and start your first screw 6 to 9 inches from the valley.
Remember you must put a rubberized membrane down in your valley to protect from leaks.
Once you are done installing your roof sheeting you can install your roof ridge cap and your opposite side Gable Flashing.
If for some reason you need to lap joint a roofing sheet which you should not because they should be one piece long enough to cover the length of your roof pitch…. then you need to overlap about 10 inches with the upper most piece on top and use a special sealer / membrane. Don’t do this unless you have to.
This is not the most difficult job in the world but it can be extremely dangerous. Most codes require that roofers wear safety harnesses when they work but you never see this in the real world because most full time roofers have a skill for walking roofs. As a first timer even if you can walk joists you should really think strongly about getting a harness.
Cost will be a little more then shingle style but there are added benefits from steel roofing including your ability to gather rain water for use in your garden or home. Asphalt shingles pollute rain water and make it not suitable for consumption.