Flat Roof Information
Flat Roof Systems: The point of any roof, including flat ones, is to keep your property or home dry and safe. Your investment is protected by a good roof from the heat of the sun, snow, rain, and other outside elements in St. Petersburg. However, built into the design of many of the market’s current technologies used in flat roofs are some major drawbacks. Truthfully, the majority of these flat roofs fail in their main purpose shortly after installation.
There are many flat roofing choices and every roofing contractor assures you that they provide the best product. However, how can you tell when you are getting a good deal and which one should you choose? Here is a summary of the most popular of the choices for flat roofing needs. After reading, you can make a decision about which type will work best for you.
Among many residential building and home improvement contractors and architects, there is a common misconception that problems are built into a flat roof. In actuality, flat roofs cost less than sloped/pitched roofs, they are easier to build, and they are quite convenient once installed. For example, if your building is very large, a flat roof is your best choice. Additional engineering is a requirement if you want to build a pitched roof that will remain reliable due to the additional structural weight.
Large HVAC equipment can be readily installed on a flat roof. If a different roofing choice were made, this equipment would have to be located on the ground. Flat roofs also work well as penthouses, patios, and as a roof top deck. Among organizations and companies in St. Petersburg, Florida that are environmentally conscious, green roofs are becoming more popular.
When the environmental benefits and the cost of constructions are compared, sloped roofs come in at a distinct second when compared to flat roofs, due to the asphalt shingles that are oil based on the sloped roofs. Every 12 to 15 years, these shingles wind up in our land fills and they continue to be steadily manufactured.
The Disadvantages And Limitations Of Flat Roofs
There are a some downsides associated with flat roofs. A primary one is that snow and water remain on the roof because it has no slope. With proper drainage, the water can be removed, but the snow will stay there until it melts away. This fact means that architects/engineers must use building components designed to take a higher structural load. Flat roof installations have been haunted for more than a century by ponding water. Ponding water is responsible for causing leaks and prior to the creation of single ply membranes, there was to economical and effective way to prevent this. During the initial stages of design and construction, the problem had to be dealt with. Even with the installation of multiple drains and a slight pitch, more than 75% of all flat roof leaks were caused by ponding water.
Currently, the solution to this problem of ponding water uses a slight roof pitch, such as the use of tapered insulation within space metal buildings to direct the flow of water to drains. Small amounts of ponding water no longer cause a problem since IB PVC/CPA roofing was created with its hot-air welded seams. Structural damage to your building or house can be caused by large quantities of ponding water, so an adequate drainage system is still required.
Flat Roof Types: Modern Types And Roofing Technologies That Are Now Outdated
1 Multiple Ply Roofs (Outdated): Some of these roofs were built more than 100 years ago.
2 BUR (Build-Up Roof)
3 Gravel And Tar
4 Bitumen, Modified
5 Rolled Asphalt: sometimes uses tar paper as base ply, usually installed as a single ply.
6 Single Ply Membranes (Modern): new to the market within the last thirty years.
7 PVC Roofing (IB Roof): The reason that only IB roofs are installed by our company is that this IB PVC roofing membrane is one of the best completely fat and low-slope roofing products available on the market. In many different climates, it has been proven to perform free of leaks and has gained a spotless reputation during the 30 years of its existence. The building’s exterior, interior, and all of its contents are protected by IB roofs from the tropical paradise that is Hawaii to the frigid north lands of Alaska. Since 1978, there has not been a single failure. The original design is still in use today and your roof will remain completely water tight due to the use of hot air welded seams.
8 Epdm Rubber Roof: With no special equipment required for installation and its extremely low price, this flat roofing material is popular among contractors. However, adhesive breaks down in 5 to 7 years and since the seams are glued together, these roofs are likely to leak. In addition, far too many flat roof contractors don’t gain the proper training and knowledge before installing them in the residential roofing market. (In the commercial market, this is not so much of a problem.) Because of this, on roofs that are still fairly new, we regularly receive calls to service rubber roof problems caused by poor workmanship.
9 TPO Roofing: At first glance, this single ply thermoplastic roofing membrane looks like PVC roofs. However, there are many problems with these roofs, as you will find once you start looking. The majority of the problems occur during manufacture when important ingredients are skipped. Three generations of this product have had to be scrapped.
10 Sprayed Foam Roofing (SFR, not single ply)
Outdated and inferior technologies for flat roofing
On older buildings, these are very common, although these systems are also installed on many newer buildings as well. However, on commercial buildings, they are rarely used today. Many roofers continue to install them on small commercial and residential roofs so they continue to be produced. This can be credited to a lack of knowledge about better solutions among roofers as well as the low cost of the material. It is a sorry thing to find skilled roofers offering their customers such an inferior product. Without going into great detail, I will briefly describe them because it makes me sad to hear roofers say that they think torch-down is the best.
Torch Down/Tar And Gravel/BUR: Using either a torch (open flame!) on your roof or applied with a mop after tar has been preheated and taken to your roof (hot mopped), layers of ply soaked with this hot tar is applied to your roof to get a multiple-ply roof. On top of this sandwich, gravel is applied to protect the roof from the devastating ultraviolet rays from the sun and foot traffic. There are many variations to the procedures described above.
Modified Bitumen: The method is similar to the torch method described above. However, bitumen is quite a different type of material than tar. Modified bitumen is more flexible and strong because elastomers and rubber are added to the formula.
Rolled Asphalt: Crushed stones are glued on top of tar paper that is saturated with asphalt. An overlapping pattern is used to install the rolls. It is applied using a cold mop and attached to the deck of the roof using nails. Tar is used to seal the overlapping seams.
Flat roofs have some problems associated with them
The fact that they are flat is the first problem. Water has nowhere to run to from these roofs. In order to eliminate the problem of water accumulation, proper drainage must be added. After every rain on an older roof that has not been leveled, water puddles appear and remain until they evaporate. This is known as ponding or standing water. Most roofing systems have no way to deal with ponding water. in fact, if water ponds on the roof, the warranty is voided out by most roofing systems manufacturers. Other major problems include holes made for things such as drains, roof hatches, chimneys, exhaust or vent pipes, and skylights. However, the seams remain the single biggest flat roof problem since these are where leaks most commonly occur.
On every type of flat roof, you will find a seam (except for small roofs which only require a single sheet of membrane for roofing) which requires some type of adhesive to put them together. Due to changes in the weather, the adhesive breaks. (In the New England area, in a single day the temperature can change by many degrees.) Condensation also affects the adhesive used on the seams. During the summer and winter months, the condensation, which sits underneath the roof covering, expands. However, when water freezes during the winter time, it dramatically expands and can break the seam. Our roads experience the same type of phenomenon. Those potholes are a result of the same processes. Water expands as it heats up during the summer. On the surface of the roof, you can sometimes see bubbles. This is due to the membrane being lifted by the water vapor. Finally, the quality of the adhesive and the workmanship are major factors to consider. The process is different for other roofing systems, but the same shortcomings are shared by many of them: The need to use liquid resin, hot tar, glue or other adhesives. Roof penetrations need adhesives to provide flash, but the adhesive used is rarely as big a problem as the quality of the workmanship.
Ecobuilt Roofing | Building Contractors
St. Petersburg Flat Roofs Installer
(855) 547 2454