The two most common types of roof penetration flashing flat roof details are pipe boots and pitch pockets. Pipe boots are used to place constant compression on tubing or other pipes that vent out through the roof. Pipe boots are cut to size and finished off with a bead of water cut-off roofing caulk and a hose clamp to place a continuous amount of tension on the roof pipe boot. Pipe boots are excellent for pipes that are 1”-10” in diameter and may be used for dryer vents, plumbing vents, and furnace flue lines.

The second roof penetration product addresses unusual shaped objects that extend through the roof line. Pitch pockets are set in place and then filled with a high strength resin that hardens around the roof penetration. Pitch pockets are especially useful for wires, smaller gas lines, electric lines and HVAC copper condensation lines. Pitch pockets are required by every manufacturer to obtain a system warranty and it is recommended that all repairs be made in accordance with manufacturer’s specification details and the Ohio Building Code.

One of the most common problems with commercial roofing systems is the existing membrane attachment to the walls. Several details are necessary to ensure that a commercial roof parapet wall does not have problems and it is recommended that all universal manufacturer roof parapet details are followed to correct existing problems with the way that the roof attaches to the walls.

Commercial roofing sometimes uses internal roof drains that capture the water from on top of the roof and funnel it through a pipe inside the building down to the storm sewer. These commercial roof drains must be installed in accordance with manufacturer’s details. It is also extremely important that roof drains be kept clean and free of clogging debris that would cause water to back up and eliminate water’s ability to drain off of the roof. All drains must be sumped slightly lower than the field of the roof to encourage water to move toward them.

Most commercial roofs with four parapet walls have a roof scupper box to allow water to pass through walls into a collection box or conductor head at the top of a downspout. These are used sometimes as the primary method of evacuating water off of the roof but are also used as overflow devices in case the primary drainage system cannot keep up with the amount of water trying to be removed from the rooftop.

Most flat roofs in Columbus Ohio have a structural taper where the building rooftop is engineered to slope slightly to one direction allowing for drainage. It is critical that the edge of the roof be installed per manufacture’s specified details and it is equally important that the gutter system be regularly cleaned of debris that can clog the gutter.

Just as it sounds, the roofing membrane is laid out over the entire surface of the roof and the sides of each sheet are secured in place with special barbed plates or with seam batten strips. Mechanically fastened roofs are slightly less resistant to high wind speeds and are not as attractive as a fully adhered roof but they are among the most cost effective flat roof designs. The cost effectiveness is due to the fact that labor requirements are reduced during installation and no adhesive needs to be purchased. A mechanically fastened roof is an option over both a metal deck and a wooden roof deck and is the most popular system being utilized by architects in new construction in Columbus Ohio.

Tried and true, EPDM rubber roofing is nothing new. Rubber membrane roofs have been around for forty years and still have a strong hold on the low-slope, flat roofing market. These rubber roofing membranes typically require very little in the way of special tools for installation and are rated to last anywhere from 10-30 years. A rubber roof can be mechanically attached or fully adhered, and if installed properly can be a great choice due to their reasonable price and ease of installation.

Modified bitumen roofing has been around for a long time. The United States Treasury building and Facebook corporate headquarters both have modified bitumen roofs. Modified bitumen is a good option for a smaller, low sloped area that is visible because the surface covering is available in different colors. Modified bitumen roof systems can be either applied cold or blow torched together. Major advantages these membranes offer are that they are self-healing and resistant to small punctures. They are also an excellent roof choice for a restaurant because they do not break down easily when cooking grease splatters on the roof.

A flat PVC roof system installed by Cap City Restoration is a quality system. Sheets and penetrations are joined at the seams and melted or “welded” together with special hot air welders. PVC welds are four times the strength of the seams of traditional rubber roofing and are far more tolerant to ponding water. Several years ago, PVC membranes developed a bad reputation due to a problem with the plasticizer within the sheets, and many cracked and failed prematurely. Since then, PVC roofing has been reformulated and the problem has been resolved. PVC is the best choice for restaurant roofs as they are extremely resistant to cooking grease from fryer hoods that can splatter on the roof.

A TPO roofing system is the commercial roofing system preferred by Cap City Restoration. Like PVC roofing, TPO is a reinforced membrane with woven fibers that offer added rigidity as well as resistance to shrinkage. As with PVC membranes, the seams and penetrations are melted or “welded” together with special heat welders for details and the majority of the large seams are robotically fused together. These welds are four times the strength of the seams of traditional rubber roofing and are far more tolerant to ponding water. TPO roofing can last 10-30 years and our installers attest that TPO welds easier than PVC due to the fact that TPO has a lower melting temperature than PVC. Both TPO and PVC membranes can be mechanically attached or fully adhered.