Metal roofs are frequently specified by engineers, architects, and contractors because they are lightweight, durable, and relatively easy and inexpensive to install. However, they have one major weakness, leaks, which often develop along the seams of metal roofs due to rust, corrosion, deterioration of fasteners, poor joint design, or structural settling. Fortunately, Tillotson Enterprises can help you compensate for these problems.
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Metal Coating System Comparisons
Metal roofs wear out over time due to a number of things which can lead to water in the building. The neoprene washers on the screws or nails wear out, and the screw holes become oblong due to the expansion and contraction of the metal. The mastic that is put between the sheets along the seams will eventually get hard and crack. Skylights and seals around penetrations such as vent pipes are also a common cause of failures.
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Cons Some contractors use cheap coatings which will not last. Some coatings get brittle with age, turn chalky; or get hard and crack over time. Some contractors try to cut corners by not using fabric for reinforcement on the seams. Due to product or application errors, the coating doesn’t stand the amount of elasticity required, and cracks appear on the seams which causes system failure.
Pros This system does not add any additional holes in the roof. It is anywhere from one third to half the cost of other alternative roof systems (single ply, new metal roof, spray foam). This system is lightweight and the white top coat makes the interior of the building 10-15 degrees cooler. The MR system stops leaks! This may sound funny but we have repaired some new metal roofs which were leaking even before they were completed. The MR system solved their problems! The installations of a MR system will not interrupt the purpose of the building being roofed.
A new metal roof doesn’t come with a “leak free” warranty with many contractors. The roof may come with a 20-year warranty on the building but read the fine print, this is not for a leak free roof. They will come out for about a year and put caulk on seams, etc. to show effort to stop leaks until you finally get tired of calling or they say their obligation is up. With the Tillotson MR system you can get a 10-15 year “leak free” warranty on material and workmanship. The roof system can be written off in one year in taxes as “maintenance and repair”; and does not depreciate out like a new metal roof, single ply; or foam roof needs to be.
Metal over Metal This is where a new metal roof is placed over the old metal roof called (retrofit) or the old metal roof is torn off and a new one put in its place. This is fairly self-explanatory. There is, however, some misconceptions about this process. When we started roofing over 20 years ago, the type of roofs that we applied the MR system on were about 20-30 years old. In the last several years the age of the metal roofs has drastically decreased to 10 years old to not even finished. Yes, you read correctly, not even finished. Today’s material and labor in constructing buildings is not of the same standard as buildings constructed 20-30 years ago. I believe that our industry suffers from a lack of experience and pride of workmanship. Another problem is that all the screws today are put in by electric drills which may not be set property causing screws to be over-tightened. All together, this makes for less than quality work. Don’t get me wrong, there are still good roofs put on by good crews, but I don’t think you can assume a leak free roof every time. The roof may come with a 20-year warranty on the building but please read the fine print.
Tar (BUR) Tar roofs have been popular from the beginning of the commercial and industrial roof systems age. Again, in my opinion these types of roofs are dated technology. These kinds of roofs were being put on before man ever walked on the moon and, basically, the process has not changed. Actually, this process is not even as good today as 30-40 years ago. The tar used today does not have as long of a lifespan as the tar used years ago, due to EPA regulations. Another problem is that today’s worker will not labor under the conditions necessary to perform the work needed to accomplish this type of job. On a 90 degree day in the summer working on a black surface around hot tar, it is very possible that the roof temperature can reach 150-170 degrees. These systems, which used to last 20 years, are now only lasting 10 years. Once they wear out you tear them off and replace them with a new one. They are black, not white and are not energy efficient. Rock is put in the tar on these systems for two reasons: to protect the roof from the weather and to re-heal itself from when the tar gets hard in cold weather and then warms up and re-melts and flows back together again. Due to EPA regulations, tar does not have the ability to get hard and re-melt over and over like it used to.
Torch down This roof system is often associated with stories of roof contractors burning down buildings. This system is an attempt to modernize the tar industry. Tar and rubber emulsion are combined and then blended together to make a hybrid roof system. This is accomplished by taking the sheet provided by the factory and heating it to the point of melting with blow torches which glues the sheet to the roof. Three major problems occur with this process. The first of these is obvious, wherever you have fire on a roof the fire can get out of control and potentially spread faster than anticipated. Next the seams tend to be a weak spot of this system causing roof failure. And finally, the sheet does not always become hot enough to properly adhere to the roof, which causes bubbles.