Install Metal Roofing Over Asphalt Shingles – The How To
To minimize the work and time, a lot of people are asking if they can directly install metal roofing over asphalt shingles. It is possible but there are important steps to follow. First, you have to determine if it is still possible to install the new roof over the old one. It is always best to refer to the manufacturer's instructions prior to doing this, but generally, the possibility to install metal roofing over asphalt shingles depends on the condition of the old shingles.
When inspecting the old asphalt shingles, you must carefully check conditions such as buckles, cracks, or cups. If these are present in the old shingle, you have to replace or remove the old one so that the new metal roofing will be installed over smooth and flat surfaces. It is also important to check the number of asphalt shingle layers on the roof. If there is more than one layer, you have to remove the shingles as some local building codes have weight constraints when it comes to the number of layers being covered.
According to the installation guide for metal roofing, it is also important to make sure that there is enough or proper ventilation before you install metal roofing over asphalt shingles. Most often, you need to put batten layers which are about 1x4 boards that will lay up the metal roof from the eave to the ridge with specific spacing to allow enough air to flow from the eaves up to the vent of the ridge. The spacing depends partly on the building codes in your town and partly on the recommendations of the metal roofing's manufacturer. To make the screwing of the metal roofing easier, make sure to place another battens layer on a specific horizontal spacing. This will give parallel lines of sold materials across the roof for the screwing of the new metal.
Tips on how to install metal roof also include keeping everything straight and square and keeping things in line with some of the basic building rules. To do this, you can use a roofers or builders square to mark the corner and measure out around 3 units across, then 4 units up to connect a diagonal line between the two ends of the lines. The longer each line, the more accurate result you can get. Once you get a perfect square, mark a line on the horizontal and vertical, so that you can have a guide for your initial panels. The second panel should lay on the edge of the first panel so that the two panels will interlock. You should also start the metal roofing on the edge/side away from the winds; this way, the seams will be overlapped in such a way that the rains and hard winds cannot blow water into the metal grooves, or worse tear off the roof or walls.
If you have not done this before, it might be hard to install metal roofing over asphalt shingles by yourself. Thus, it might be better to hire a professional roof installer to do this for you. However, if you have tried this before or consider yourself a fairly handy person, then you can do the task to save on the installation cost.
