Tom Parker, TCParker and Associates
Use of polyurethane roof tile adhesives continues to grow in the Florida market based on the superior uplift values that can be obtained and the fact that penetrations to the underlayment are minimized.
It is worthwhile noting that each manufacturer includes product specific instructions with each package and that these should be read and understood by all installers. Successful installation requires that product is prepared and applied per these instructions.
Each manufacturer has performed uplift testing with specific amounts of adhesive applied to each tile in a specific pattern. The design calculations for a tile roof are based on the published uplift numbers, therefore it is up to the installer to ensure the foam is applied properly.
Preparation: Begin with confirming that the products you choose have a Florida Product Approval or an NOA (Notice of Acceptance) via miamidade.gov/building. The Florida Product Approval or NOA number is typically listed on the package as well. Once confirmed, note that the products have a range of optimum temperature of storage and for application. Single component products typically
require shaking prior to use. Two component products require calibration prior to and during application. Consult manufacturers’ instruction manual for details.
Application: Each manufacturer provides detailed written instructions along with drawings detailing the exact placement of the material (paddy or bead location) and the quantity of material (paddy or bead dimensions). These may be different for different tile profiles. It is imperative that the required amount of material is placed on each tile to ensure the design uplift numbers are achieved. In some cases, the manufacturer provides the square inches of contact area required and makes recommendations to pull up a certain number of tiles to check the contact area. Ensuring good contact area is always a prudent practice.
The adhesives also have a specific “open time” or time until the foam “skins over” which must be observed to ensure good adhesion. If the foam begins to cure before the tile is placed, it is unlikely to yield the designed uplift numbers. When in doubt, remove the foam and re-apply. For the single component products, temperature and humidity have more of an impact as these are cured from moisture in the air. Two component adhesives are chemically cured and are less impacted by humidity. The manufacturers provide
a maximum time between application and placement of tile, typically one to four minutes.
Also recognize that there are specific bead/paddy sizes and placement for field tiles, eave tiles and hip and ridge tiles. In some cases, the amounts are dramatically different for each of these locations, so be sure to consult the manufacturers
specific instructions.
Based on the roof pitch, other fasteners may be needed in addition to the foam, again refer to the manufacturers' instructions.
Finally, the manufacturer’s instructions, a Florida Product Approval and Miami-Dade NOA call out that each installer needs to be trained and certified by a qualified trainer. All manufacturers provide this training, and in many cases product distributors have certified trainers as well who can certify installers.
Given that the Florida Product Approval or NOA indicates adhesive must be installed per the manufacturers’ instructions, all the above items need to be followed.
Polyurethane foam tile adhesives are a great way to provide the homeowner the most secure roof system possible. Given the history of weather events in Florida, it makes sense to have this offering available to your customers. Keep in mind that manufacturers, TRI and FRSA’s expertise is also available to help you ensure successful installation.
Tom Parker, owner of TCParker and Associates, is a Manufacturer’s Representative for Dow TILEBOND and other products. Tom worked at Dow for 33 years where he managed the spray foam business. He is trained as a chemical engineer and is a Registered Professional Engineer. More importantly, he grew up working in residential construction in the family building business.
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