Looking for a new roof? If so, you will find that there are many options available in the roofing industry. These options can range from multiple variations of asphalt shingle types to many variations of metal panels.
One of the many questions posed to a professional contractor is, “Can metal roofs be installed on shingles?” The simple answer is yes. The dichotomous nature of installing metal over an existing tile roof requires many steps. We will examine these steps in more detail to help determine if retrofitting an existing metal roof and asphalt shingle roof is an innovative idea.
There are several things to consider before deciding to install a metal panel roof over an existing asphalt shingle roof. The first thing to determine is whether the roof plywood or plank deck is secure and solid under the existing roof. Essentially, the roof deck must not be damaged by water entering the old roof through any holes or any other penetrations within the roof field. This will require a bit of research work before installing the new metal roof.
It is highly recommended to inspect all roof decks and frames from the roof side of the attic. Look for dark spots, moldy spots, water trails in plywood or roof decking, and cracked or split beams. This must be done very carefully, as a mistake can damage your roofs or cause significant injury to yourself. Once these things have been validated to be okay, the next step is to start preparing the roof.
New 1×4 lumber strips should be installed vertically and horizontally every 24 inches across the entire plane of the ceiling in the horizontal from bottom to top. It is highly recommended to use wood screws to secure the new 1 x 4 wood strips. Once this is complete and a holistic approach to the entire ceiling, it is time to install the ceiling panels. Note that all roof penetrations will need to be covered with flashing that will work with the metal panel chosen for the roof application.
In this step, the choice of metal panel is critical to the longevity of the life of the roof. There are metal panels that screw through that into the face of the metal that are just nothing more than a fancy barn tin. The problem with fancy tin barn panels is that the rubber grommets will eventually dry out and fail, thus creating a roof leak that can undermine the whole reason a metal roof was chosen to begin with.
An easy way to avoid bolt-on roofing material is to use a concealed closure metal panel. These types of panels are called standing metal seam. It is highly recommended when choosing a metal roof to think about longevity. Stated succinctly, a concealed closure panel is going to last the life of the metal with minimal chance of leakage, as well as failing roof penetrations over time.
