Over 
Call for FREE ESTIMATE A lightweight metal roof can be placed over shingles, as long as each shingle has remained in fair condition.
Initial and preparatory steps
Roofers In San Mateo will have the shingle roof inspected. If it is not in good condition, then they will plan to deal with a replacement project that would entail removal of all the shingles, before installation of any new roofing.
Make sure that the inspector has some familiarity with the method for assessing the home’s ability to withstand the amount of weight in a metal rooftop. Not every home has the ability to withstand that amount of weight. It is best to do some research on your own, in order to learn about the building codes in your municipality. Are there any that put restrictions on the installation of a metal roof?
Consult a professional, in order to obtain an estimate for the cost of the planned project that includes replace any rotting rafters or beams.
Next steps
Cover the old roof with underlayment and put purloins on the old deck.Put edging around roof and screw the metal roofing to the purloins. Match the screws to the type of metal selected for the roofing. If the roofers are using aluminum, plan to shop for tight screws; those should get spaced widely apart.
Regardless of metal chosen, the roofer or DIY expert must work with panels. There could be solar panels, in combination with metal panels. Do not view the project as complete, until after both the flashings and ventilation have been installed. If new roof’s installation has provided homeowner with access to solar energy, then the chosen ventilation device could be one that made use of the sun’s energy.
Benefits enjoyed by homeowner that has arranged for completion of the steps listed above
• The lifetime of a metal roof exceeds to a marked extent the 30 year-lifetime of roofing that that contains shingles.
• No termite would show much interest in taking up residence in a home with a metal rooftop.
• The metal reflects the sun’s rays and keeps the family’s residence cool.
Linking preparatory actions and benefits
A metal roof’s lifetime might get reduced, if the homeowner had chosen to put new roofing over damaged or aging shingles. Obviously, a termite would have less interest in a rooftop structure that contained both shingles and metal. Still, the shingles’ condition could work to determine the roof’s appeal, in the eyes of a termite.
The presence of solar panels would reduce the square footage for the UV-reflecting metal surfaces. Yet, energy from the sun could be used to keep any cooling device working for a long time. In other words, the metal’s cooling effect would be supplemented. Consequently, the device’s prolonged usage would not force the homeowner to deal with some unpleasantly high bills.