Are you planning on re-roofing your home this Spring, or sometime soon? Have you ever considered installing a new metal shingles roofing system on your home or garage by yourself? If so, read on to learn more.
Why go with Metal?
Why waste your time and money on the installation of common roofing shingles, when you can install steel shingles metal roof, a sustainable roofing alternative that, unlike asphalt shingles, is energy efficient, long lasting, and environmentally responsible. In this guide, I am going to show you how to prepare your roof’s deck, and provide instructions on how to do a basic metal roofing installation for your home.
Difficulty Level: Moderately Challenging
In order to complete metal roofing installation successfully you need to know how to use basic home improvement tools and a ladder safely, and that you have a certain level of experience with general home improvements.
Tools You will Need
- Sheet Metal Sheers
- Chalk line
- tool belt
- Roofing hammer
- tape measure
- 90 degree square
- color string
- metal roofing materials
- roofing underlayment
- Safe Ladder
- Personal Safety Harness
In this guide, I am going to demonstrate the basic principles involved in the installation of green metal roofing system made from metal, a green building material that can help you save over thirty percent on your energy costs. In order to show you the basic steps, I will show you how to install a metal shingle roofing system over a basic gable roof.
Metal Shingles Roof can be made from aluminum, steel, zinc, or copper. Regardless of what material your system is made out of, the installation techniques will be quite similar for metal shingle roofs.
In step one, we need to decide weather, we are going to tear-off our existing roof, or install metal shingle roofing system over the existing roof. If your existing roof has only one layer of asphalt shingles, and the roof’s deck is believed to be in a good condition, then we can roof over top. But, if there are two or more layers of roofing shingles, or if the condition of your roof’s deck is questionable, then you have to tear off your old roof, repair the roof deck, and install a breathable roofing underlayment before installing your new metal roofing system.
If your roof deck is made of boards rather than plywood, and there are some spaces in between the boards (You can inspect your roof deck from the attic), then you may have to install 3/4 inch plywood over the entire roof’s deck in order to cover any spaces in between the boards, and to avoid driving roofing nails that secure metal shingles to your roof deck, into an empty space in between the boards comprising your roof’s deck.
An underlayment plays a critical role of a roof underneath a metal roof. Installing a breathable
roof underlayment underneath your metal shingles roof, will allow any moisture that may form due condensation, to evaporate rather than it becoming “trapped” underneath the underlayment, and thereby causing your roof deck’s boards to rot. Certainly, we do not want that to happen, that’s why we will install a breathable type of roofing underlayment over your roof’s deck, or over the existing roof provided that there is only one layer of shingles.
Roofing underlayment has to be installed from the bottom-up with a six inch overlap over and after every row of underlayment. During the installation, your roofing underlayment has to be well stretched from side to side to ensure that it does not wrinkle, when you sit or walk on it. In other words, it is not enough to simply roll it from side to side and nail it in. There has to be some tension from side to side in your roofing underlayment.
Should I install Ice-and-Water over eaves and valleys of my roof?
If you happen to live in a northern climate with frequent snow fall, then you will need to install one row of Ice-and-Water over eaves, and in the valleys of your roof, if you have any. You can then continue installing your roofing underlayment with a 6 inch overlap over the preceding row.
Once our roof deck is fully covered with a breathable roof underlayment, it is time to install a drip edge/starter metal flashing. We will start out by installing a starter/drip edge flashing, by securing it to the eave of the roof deck with a metal roofing system manufacturer approved fasteners. For aluminum shingles, it would be ring shank nails made out of aluminum, while for steel shingles it would be galvanized steel nails.
The drip edge flashing is usually installed starting from a left gable, and progressing towards the right. It gets secured to the roof deck by appropriate fasteners every 12 inches on center.
Once your drip edge flashing is in place, it is time to install a gable flashing. We will start at the bottom corner of our gable, and we will align our gable flashing to the side of the gable of our roof overlapping the starter/drip edge flashing. Each successive gable flashing will overlap the one below by a minimum of 2 inches. Gable flashings can be inserted into each other, but it has to be inserted in such a way that a rainwater running down never gets underneath the system.
Now, it is time to install our first metal roofing shingle. When installing metal shingles, it is usually recommended to start with half of a shingle, or 3 quarters of a shingle length depending on the system design and manufacturer’s specifications. Some metal shingles roofing systems such as the one by Tamko Metal Works, have small indents on the back of each shingle that indicate where and when to make a cut, and for which particular row of shingles, so that your metal shingles are laid out and installed in a correct pattern.
Refer to the pictures of metal shingles being installed below to get an idea. Note that a metal shingle has an interlocking design. We lock our first shingle into both gable and starter flashing. We will have to use metal sheers to make a small cut in the bottom left corner of the shingle to allow gable flashing protrude through the bottom of our first shingle. All we have to do is make a small cut in the lock of a metal shingle about six inches away from the left side of the shingle, and bend that small portion of the lock tightly to the shingle itself.
Thus, it will be as if the first six inches of the lock were never there. The rest of the locking mechanisms of the shingle get locked into both the gable flashing on the side, and at the starter / drip edge flashing, at the eave / bottom. Once our first shingle is installed, we secure it with nails or special screws in accordance with metal roofing system manufacturer’s specifications.
Now that our first shingle is installed and locked into gable and starter flashing, it is time to cast some straight lines in order to ensure that all metal shingles are installed in a correctly aligned fashion according to vertical and horizontal alignment lines.
We will use a special tool called “square” and a level in order to cast the lines, and then we will use colored strings as our visual guidelines of the straight lines that we can adhere-to when installing successive rows of metal roofing shingles.
Steel shingles should be installed using a so-called row-and-column diagonal installation methodology, which makes it easy to add and secure metal shingles working your way up from preceding / lower rows of shingles upwards along a diagonal.
When we reach an opposite, or a far side of a gable, we have to cut off a part of a shingle so that it will fit and lock into the gable. Use carpenter’s pen to indicate where a shingle needs to be cut in order to insert it into the gable flashing.
At this point you have reached a ridge of the roof. Now, you may choose to install a ridge vent before installing ridge caps that come with the system. You will want to install a ridge vent, only when and if you also have soffit vents in your roof. If you do not, then installing a ridge vent will be useless, and you will get a better ventilation of your attic by installing gable vents, or system specific passive vents, instead.
Should you choose to install the ridge vent, make sure that you lay it out nicely, and secure it with the ridge cap that gets installed over the ridge vent as you go along. I recommend using some straight line guides to ensure that your ridge vent and system specific ridge caps are installed in a straight line.
Ridge Caps are installed by nailing it down on each side, and inserting next piece into the preceding ridge cap.
At this point you are all done, congratulations!
I have intentionally left out chimney and skylight flashing in order to keep the instructions easy to follow.
Here is a picture of the chimney flashing to give you an idea how it is done. This step is quite complicated and I recommend hiring a pro to show you how it should be done. You will also need to use caulk and “water stop” when installing chimney metal flashing.
We have covered the basic steps to install metal roofing yourself, and at this point you should at least have a basic idea of what is going on. Now, may wonder how to get metal roofing materials, and what kind. You will want to buy Energy star rated materials that qualify for green building tax credits. I recommend using steel shingles roof system that can be obtained at a professional roofing supply warehouse for contractors.
Tips, Facts, and Warnings
Metal is an Eco-friendly roofing material that can offer as much as forty percent in energy savings, lasts two to three times longer than conventional roof, weighs significantly less than asphalt, helps to pay for itself over time, provides energy efficient tax credits, and helps to appraise the value of your property.
When a new metal roof is installed correctly, it eliminates the need for any on-going, costly roof maintenance and repairs.
Safety is the key. Make sure your ladders are properly secured at the top and at the bottom. Wear a safety harness, and make sure that you know how to properly use your fall arrest equipment. Never work alone. Install your safety anchors into the studs of the roof, and not just into the plywood. Use quality screws, rather than some cheap nails that will pull out should you take a fall.