As with any roofing project safety is always first. You know you will be working on an elevated surface so be sure to think ahead on what type clothing you should wear, your footwear, the safe use of ladders and tools, and scope of the project to ensure issues such as power lines are not a danger.
When replacing a flat roof you begin by removing the old existing roofing material. Usually the best tool to use in removing the old material is a spade. The spade will allow you get underneath the old roofing material to pry it up. Once the old roofing material is loosened and pried up with the spade you should be able to lift off large sections of the material by hand. There may be several layers of roofing material that must be removed making the progress slow and laborious. On occasions the old roofing material may not come off in large sections but will call for patient chipping away of small pieces. Nonetheless it must all be removed until you have a clean smooth surface.
Once the old roofing material is removed from the roof surface, and any flashing or framework attached to the wall or perimeter surfaces is removed, you are ready to install the new flat roof. Flat roofs don’t generally last as long as traditional sloped roofs do and in the past were prone to water leaks. Although in recent years roofing material for flat roofs have significantly improved.
There are several types of roofing material that can be used on flat roofs. But it’s more than just the roofing material itself. It’s making sure each step from choosing the right materials to the framing, the sheathing and finally to the finished roof product is correct. And that includes the installation of each step. And remember a flat roof is never really “flat.” In order to keep water from pooling the roof should have an incline of at least 1/8 inch per foot.
Here are some types of Flat roofing materials and how they are installed. “Rubber Membrane” also known as EPDM is a lightweight rubber membrane installed over a drip batten with deck adhesive.
“Thermoplastic Polyolefin or TPO” is made from polypropylene and ethyl propylene rubbers. It is a single piece of membrane that is adhered or mechanically attached to the decking on the roof.
“PVC Membrane” is constructed of two layers of PVC roofing materials with polyester in between for added strength. The membrane can be installed 3 different ways; (1) laid loosely across the prepared surface of the roof and covered with washed river rock, or pavers (20 Fully- Adhered, or (3) Mechanically-Attached.
“Built-Up Roofs” are constructed by using hot tar and gravel. They usually have three or more layers of water proof sheets of tar and gravel for strength and durability.
“Modified Bitumen” is a single layer of adhesive roofing material installed by torching or self-adhering options.
There are other types of flat roofing materials like “Metal” and “Liquid Coating” as well.