Tar and Gravel BUR (Built-Up-Roof) Restoration
One of the popular roofing systems in Florida has been to lay ply sheets of asphaltic paper over various types of insulation using hot tar or cold-pitch tar and ballast the system with gravel. The tar and gravel method has proven to be one of the most durable roofing systems for commercial and industrial buildings exposed to the harsh Florida climate. Building owners have benefited from 20 or even 30 years of successful waterproofing from these systems, but Florida Building Code has recently prohibited the installation of tar and gravel roofs.
As tar and gravel roofs start to breakdown, customers face a decision: re-roof or restore? After a thorough roof evaluation, Commercial Energy Sytems can usually recommend restoration rather than replacement. The solution is a closed-cell polyurethane foam, followed by high-solid (96%) silicone elastomeric for additional waterproofing and UV protection.
Spray polyurethane foam provides superior waterproofing and insulation benefits. In addition, foam can be tapered to provide positive drainage in low, depressed areas and increase the building energy efficiency. Every 1″ of spray foam adds an R-value of 7. After the white silicone topcoat is applied over the spray foam, the installation provides a nearly 100% insulated roof for improved building energy efficiency and superior waterproofing. And all of this can be done without tearing open the roof, closing the business, or affecting routine business operations.
Process for Restoring a Tar and Gravel Roof
- Remove and haul away all the loose gravel.
- Power wash the roof, clean and dry.
- Make any necessary repairs to ensure a watertight system.
- Apply spray polyurethane closed-cell roofing foam and provide tapering to ensure positive drainage.
- Apply a topcoat spray of high solid (96%) commercial grade silicone elastomeric (white).
- The roof restoration procedure described above provides a 10, 15 or 20 year labor and material warranty with NO exclusions for ponding or standing water.
- This process also qualifies for cash rebates from local energy service providers such as Duke Energy ($.15/sq. ft.).