There are some definite advantages of using metal products over asphalt shingles.
The most important is wind uplift. Asphalt shingles may start with a 90 to 120 MPH rating, however once the oils in the asphalt start to dry out, the shingles no longer have the same rating. Most asphalt shingles only carry a 10 year rating on their shingles. Some of the insurance companies are asking people to replace their shingles when the wind rating is no good, or pay a higher rating on the insurance.
The next factor a lot of people appreciate about metal is that some metal systems have many colors available in “cool” colors. These are colors that have a pigment in the paint process that gives a reflective quality, and still retains the rating as being a “cool” color. Metal roofs with cool colors prevent around 30% of the radiant heat, and if you install them over cross battens, they prevent almost 45% of the radiant heat. They also do not retain heat the way other products do. Concrete tile is the worst. When someone does an infrared scan at night, it is easy to see the concrete tile roof because they retain heat so poorly. The metal is also easy to spot because they do not retain heat.
Metal tiles are available that look almost the same as tiles. The cost is about the same as concrete tiles, and they can be installed in many places that are not built for the weight of concrete. Care must be taken to use a system that the fasteners have the least amount exposure to the weather. Many systems fasten the tiles directly through the face of the tiles, and when the neoprene on the fastener goes bad in about 10 years, it is almost impossible to replace them without bending or kinking the face of the tiles.
Our preference for metal roofs is mechanically locked standing seam roof systems. We don’t care for the systems that have exposed fasteners that will require someone getting onto the roof and caulking the heads of, or replacing the fasteners. Many of the shingle, tile, or wood forms that are available in metal carry great warranties. However, if you walk on the system you will crush the metal because it does not lay flat on the deck. Once the metal is crushed, within a couple of years, the metal will break and leak. Steel and copper will take longer than aluminum, but in time they will split in that area also.
Mechanically locked seamed standing seam roofs if done properly will have no exposed fasteners. They will fold over the bottom edge metal to allow for expansion and contraction, and this method will not allow wind to lift at the bottom. The only fasteners that will penetrate the panel will be at the very top, which will prevent any slippage of the metal. These fasteners will be covered by the “Z” panel that the screws go through. The “Z” panel will then be used for the ridge cap that will be mechanically attached to the “Z” panels. The beauty of a properly installed mechanically locked standing seam roofing system is that the panels have clips on the sides of every panel that are attached and will allow the panels to expand and contract with a slip joint.
If the panels are fastened with fasteners that will not allow slippage, or if they are fastened through the face, within time the movement of the panels will cause the fasteners to pull out, and fail. If done properly, all penetrations will be installed in a manner that they will fold into the metal system. The beauty of a properly installed mechanically locked standing seam roofing system is that the panels have clips on the sides of every panel that are attached and will allow the panels to expand and contract with a slip joint.
All penetrations will be done in the same manner. They will fit right into the system. It is very common for someone to install a mechanically locked standing seam system, and then cut holes into the system for the pipes. They will then use a rubber closure butyl caulk to seal the pipes. This should be avoided whenever possible.
The major advantage Tampa Roofing has when installing metal roof systems is we have a completely computerized sheet metal shop that will allow us to custom fabricate any of the specialized detail flashings that every roof requires. As opposed to hand bending detail metals in the field. We also have a Quadrell metal forming machine that will machine roll all of the metals to specific sizes for the mechanically locked standing seam roofs at the job site. As opposed to field measure and ordered sizes from someone else.
Our metals are fabricated by us, for us. Our machine is certified and approved twice a year to meet all specifications for Florida product approval. Every job is tested and approved by an outside agency to meet specific qualifications for Florida product approval.
The beauty of metal tiles is that they carry a warranty similar to the asphalt shingle manufacturer’s lifetime warranties. You must use an approved applicator, but the warranty is great. However, additional care must be taken to make sure there is absolutely NO traffic on the roof. When the roof is installed, we have found it extremely important to do all of the finish work as you lay the field to prevent as much back work as possible. We have also found it very helpful to use sheets of plywood to help disperse the weight of anyone who has to walk on the finished roof.