Commercial flat roofing
Maybe you have or haven’t noticed, but most commercial buildings have a flat roof. Your local grocery store, your children’s school, your bank, the post office, etc. Yes, some have a pitched roof, or a sloped roof, some even have a rounded roof for architectural impact. Most commercial buildings, however, have a flat roof. You may even notice a flat roof with a deck, like on an apartment building.
So, why do commercial buildings have a flat roof? It’s obviously not an architectural impact, rather ugly if the rest of the structure doesn’t have some sort of design about it. Commercial buildings have had flat roofs for many years because they are less expensive to install, they are cheaper and easier to maintain, and there is more useful space for the structure inside and outside with a flat roof.
What is the best material for a flat roof?
The most popular material used for flat roof covering is metal because of its durability, specifically aluminum. A flat metal roof has a lifespan of 30 to 35 years in ideal climate and environment conditions.
Metal is a reflective material, another bonus of a flat roof that lowers energy expenses because it reflects the UV rays. Typically, metal is in large sheets, but smaller sheets can be ordered for special fittings on a flat roof.
The downsize to a metal covered flat roof is when it must be replaced. When replacement is needed, it is required to remove all the old roof, regardless of what material was on it. A metal flat roof is prone to rust, another downside. When this happens, the above-mentioned replacement is necessary.
How long do flat roofs last?
There are several factors that can affect a flat roof life expectancy. From the quality of the workmanship to the quality of the building materials, from the climate and the environment to the maintenance and upkeep.
Because a flat roof does not have drainage like a pitched roof, it is prone to hold water. If the roofing material has any holes or tears, that water seeps through to the roof below the material. Therefore, it is important to have the roof inspected regularly to patch any holes or tears. The lifespan of the following popular flat roof materials is:
- BUR (Built Up Roof): A BUR flat roof is the most familiar and is constructed with heated asphalt and plywood layered together. The life expectancy of BUR flat roof is fifteen to twenty years.
- PVC: This flat roof material needs experienced and skilled labor to install the large sheets of this material correctly. Used as the main waterproofing component for flat roofs, it is hot welded to the pieces surrounding it and offers a lifespan of 30 years when maintained properly.
- EPDM: This material is a large rubber sticker that is carefully rolled onto a flat roof. It is difficult to install because of its size and because there can’t be any air pockets. This flat roof material has a life expectancy of 10 to 15 years.
- TPO: TPO is very much like EPDM and PVC with its durability and effectiveness. The life expectancy of TPO is seven to twenty years.
How often do flat roofs need replacing?
There are many benefits to a commercial roof having flat roofs. With proper maintenance, including regular inspection, they should last a minimum of 50 years. Over the past few decades, they have used several types of materials for commercial flat roofs, with the following three being the most common:
- EPDM – replacement averages every 25 to 30 years
- PVC – replacement averages every 20 years or longer
- TPO – replacement averages every 15 to 20 years
Do flat roofs leak more?
A flat roof does not shed water like a pitched roof. However, if installed properly, a flat roof should never leak if some maintenance as recommended by the builder and the roofing material manufacturer.
How do you waterproof a flat roof?
Water does not run off flat roofs as it does on sloped roofs, thus, it needs to be waterproofed, which is typically done with two applications of an elastomeric coating. This coating will also insulate whatever material is on the roof in addition to making it waterproof.
While the building maintenance team can do this, flat roof experts recommend having it done professionally. There are certain measures that need to be taken to walk on a flat roof, a process that commercial building contractors such as roofers, HVAC and plumbers know and understand that importance.
With that recommendation made, the steps required to apply a waterproofing material on a flat roof are:
- Measure the roof then multiply the length with the width to get the square footage. This will tell you it needs how much waterproof coating for your flat roof.
- Clean the flat roof surface with a broom or pressure washer to remove any dirt and dust. If a pressure washer is used, you must allow it to dry before applying the waterproofing material.
- Pour one gallon of the elastomeric flat roof coating on the roof and use a paint roller, spread evenly, starting in one corner and working around the roof backward. Avoid stepping on the coating and repeat after 24 hours of waiting.
Our flat roof is leaking what do I do?
The first thing you need to do is call a professional contractor experienced with flat roofs. Once you have made that contact, for an emergency temporary repair, follow these steps:
- Plastic Roof Cement: For a flat roof with EPDM single-ply, BUR or modified bitumen BUR system, create a temporary patch out of roofing fabric and plastic cement. You must clean off any loose debris and clear the damaged area of any gravel. Get the damaged area as dry as possible and then apply the cement. It should be several inches out from the damaged area using a mud knife or trowel. Next, apply the fabric and then another layer of the cement.
- Roofing Sealant and Roof Tape: This method works for BUR, EDPM single-ply, and PVC flat roof surfaces. The damaged area must be clean and dry, then wipe down with alcohol. Next, apply either polyurethane caulking or roofing tape to the area with damage.
- Duct tape: A PVC plastic sheeting flat roof can be quickly patched using common household duct tape.
Note that all 3 of these suggestions are for temporary repair only. You need to have a contractor with experience in a flat roof inspect the damage and the entire roof and make a permanent repair or resurface the roof.
Your commercial building is an expensive investment, the flat roof on that building is an investment for protecting that investment. Have the best flat roof material possible for your area’s climate and the environment will give you the longest lifespan and most ROI. Need a flat roof replacement in Fort Worth, TX? Call 817-349-0016 today!