Bob's Blog

Purchasing a New Flat Commercial Roofing System


How many of us actually know anything about purchasing a new flat roofing system? Did you know that 85 percent of all flat roofing systems are installed with a commercial product called modified bitumen? Modified bitumen is produced in thicknesses of 3.5 to 5.0mm sheets 36“ wide by 33’ long. The system is most commonly applied with a torch. The bottom of the sheet is liquefied and applied over insulation and/or a felt-paper base-sheet.

Contractors bidding on projects regularly include in their contract that they are installing a 15-year material. The job is sold, and then the contractor delivers a 10 or 12-year modified bitumen material to the client. The client never knows or thinks to check.

These are the steps you can take to avoid this scenario.

1. Always ask for the itemized receipt upon delivery of the materials for your project. Always call the materials supplier and ask what the warranty is on the materials delivered. Check to make sure the brand name matches the material quoted in your contract.

2. Ask the contractor if he is a “Manufacturer’s Certified Installer” for the materials you are specifying. Asking this single question will revolutionize the industry. You will be stunned to find that practically no one bidding on the job is certified to install the materials.
Now, you ask yourself why? The manufacturer would love to know that every roofer installing their product is certified to do so. This, in essence, means, that the roofing contractor has had his work inspected regularly by the manufacturer and that the manufacturer of the materials validates that this contractor knows how to perform all of the detail work, as specified by the manufacturer.

If the materials are not installed per the manufacturer’s specifications, then the materials have no warranty. Therefore, if you do not hire a manufacturer’s certified installer, you have absolutely no protection and, most probably, a roof that was installed at a substandard quality level. Ask that the contractor supply you with the warranty documentation supplied by the manufacturer of the materials you have in your contract.

At the end of the project, ask the contractor to inspect your new roof and give you a written report or letter to substantiate that the roof has been completed per the manufacturer’s specifications.

I recommend that you add the following wording to your roofing job contract:‚Äč

The roofing system, including all flashings and details, at [client’s address] is completed per the manufacturer’s specifications.

I, [contractor’s name], will stand behind this warranty. In the event that [client’s name] roof experiences leaking, I will respond within 24 hours and correct any and all deficiencies in my workmanship. In the event that [contractor’s name] does not respond to [client’s name] call for service, I [client’s name] have the right to contact another contractor and make repairs to our new roof to stop further leaking. [Contractor’s name] will reimburse [client’s name] for any and all out-of-pocket expenses to rectify defects in his workmanship.

3. The manufacturer recommends that this new modified bitumen system be covered with a fibrated, silver asphalt base reflective coating. This is an asphalt base coating that has a silver pigment in it to block the sun’s UV rays from wearing out the material. This coating is to be applied at 75 sf. per gallon. Ask the contractor what the coverage is of the coating he will be applying. Most contractors do not know the answer.

Check to see that the contractor has delivered enough coating to apply to the roofing system properly. In almost all cases, the coating is applied too thinly and consequently does not last.

Finally, take lots of photos before, during and after completion of the job. As the saying goes, pictures are worth a thousand words. Download them to your computer and make three back-up copies on CD. For safety, put the back-up CD’s in three different locations. If you ever need them for insurance or legal purposes, or in the event that the building is sold, they will not only be available, but also invaluable.

This article was written by Robert J. Skertich, President, Construction Management Services Group, Inc.
It was published in the Wall Street Journal, the SF Chronicle, and the Chicago Tribune.