Tropical Storms Emphasize Ongoing Maintenance Needs
by Richard K. Olson, president & technical director, Tile Roofing Industry Alliance
(Editor’s Note: Richard K. Olson is president and technical director for the Tile Roofing Industry Alliance. The association represents industry professionals involved in the manufacturing and installation of concrete and clay tile roofs in the United States and Canada, and works with national, state, and local building officials to develop installation techniques, codes, and standards for better roofing systems. Olson can be reached at firstname.lastname@example.org.)
Tropical Storm Hilary created serious damage in Southern California and the Southwest, and brought record-breaking rainfall. For the roof design industry, it will create a market for roof evaluation and development of better ongoing maintenance programs for building owners. What are the key areas that might be included?
Tributary Water Designs
With the growth of more complicated multiple plane roof designs, we are seeing issues arise from the lack of proper consideration for how upslope tributary water is being addressed. One challenge is the amount of upslope water being re-directed downslope through flashings or gutters that utilize lower roof planes for water flow. Trying to size the downspouts and gutters to meet anticipated water flow will prevent water from backing upslope and entering through the coursing of the roof claddings.
Another challenge is the location and designs of the various flashings. When roof penetrations such as skylights, chimneys, or roof accessories are low on the roof plane, there will be additional tributary water. Increasing the size of the flashing behind or adding a cricket will help water flow around the obstruction.
Where roof plains intersect walls, the use of higher flashings and z-bar can protect the siding and stucco. For tile systems, the use of a proper roof to wall pan metal will allow water to flow downslope away from the siding. Where walls extend beyond the roof edge, the pan metals should have a kickout at the end of the roof edge to keep the water from flowing onto the extended wall areas.
Proper valley flashing designs are important to help direct the water downslope. The use of a multi-rib flashing can improve the amount of water the valley can handle. For concrete and clay tiles installed on wood battens, the use of a batten extender into the valley metal helps reduce water damming.
Solar & Accessories
With the increased use of solar systems on roof assemblies, the design professional can help identify the proper location for the panels and wiring to integrate with the roof cladding materials to ensure a fully functional roof assembly. Where drop deck areas under the panels are used, there will need to be considerations for how to properly flash the transition from the existing assembly to the drop area and back up to the surface of the cladding or off the roof. The side transitions should be treated as a roof to wall to allow the drop area to be an independent roof.
Steep-slope roof claddings require the use of some form of code-recognized underlayment. The underlayment acts as the secondary water barrier and is important to the long-term life of the roof assembly. Yearly inspection can help identify any issues with the underlayment that might need addressed or repaired.
Examination of the roof cladding surface for wear, breaks, delamination, vegetation, or dirt build up is required. Vegetation is a serious concern in fire-prone areas and should be removed yearly in areas that allow such build up.
Examination of current code requirements and status of the current roof for the selected materials is required. For roofing tile, this is easily accomplished as the tiles act as independent units and in areas not subjected to code required wind designs will have only the perimeter tiles fastened, when on battens. For direct deck they will have one fastener per tile.
Ensure flashings at eaves, penetrations, walls, and sidings are not compromised or have debris build up. Check for proper sealing of stack pipe and use of deck and top flashing for roofing tile installations.
Hip & Ridge Attachments
In some areas, non-shrinking mortar or foam are used for our concrete and clay roofing tiles. Yearly inspection can identify any normal maintenance that might be needed, such as painting to avoid UV exposure.
Ensure they are clean and clear of obstructions and check for wear in the metal and any possible damming opportunities that might be present. Consider tributary water effects that might be present and repairs that should be done.
For concrete and clay roof tile, the use of an eave metal is required to help align the first course of tiles. Where raised fascia is used, the attachment of an anti-ponding metal is recommended to prevent water build up.
Solar & Accessories
Inspect for proper attachment, sealing, and wiring conduit issues that may be present. Design professionals can help in the installation instructions and call outs on designs for the solar manufacturer to use.