More Than Just Designing An Upgrade
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.)
On steep-slope roofing, the topic of accessories seems to mentally equate as being sold on upgraded systems at additional costs for your roofing projects. While accessories can add slight costs, they are more than just a product, as they can save you money over the life of the roof in increased performance and reduced maintenance. While building codes address the minimums, these accessories have demonstrated over time the improved performance when integrated into steep-slope roof designs. Here are some accessories worth considering on your next design.
Raised or Elevated Batten Systems
The additional height from a raised/elevated batten will increase the amount of natural above sheathing ventilation, which reduces the heat influx into the attic system. These elevated systems allow any water that might breach the cladding to easily exit the roof system downslope. Traditional batten systems are designed to have gaps every four feet but can still allow water to be trapped against the batten that in some climates can reduce the life of the underlayment where the silt/dirt might be present for long periods of time upslope of the batten. These elevated battens provide greater water flow in the valley and flashing metals that can help reduce future maintenance costs due to the buildup of foreign materials or restriction of water flow. The use of the raised batten system ensures that the valley and wall metals will perform as designed.
When single batten installations are used, the addition of a batten extender will allow water to properly flow in the valleys, while holding up the roof cladding. This accessory should also be considered when designing retrofit or maintenance of roof assemblies. These products are made from plastic or other manmade materials that are designed for the conditions they will experience over the life of the roof.
For steep-slope roof cladding products, there are a host of code-approved flashings to help transition water flow or prevent water from breaching the roof system. Over the last 20 years, there has been significant advancement and a transition to more flexible and self-adhering options for roof flashings in the marketplace. For many decades, the use of soft lead was the benchmark for flexible flashings for profiled claddings and is still allowed in the codes today. The use of lead on roofing projects has been a concern since 1993, when OSHA released information on the exposure to lead.
The use of self-adhering flashings can improve sealing at roof penetrations, hips, ridges, side, and headwall applications. Through improved sealing to the cladding, there will be the reduced opportunity for water penetration during exposure to wind driven rains. These products can be used for traditional flashing points, areas where weather protection are required, and for roof transitions. Most of these options provide UV resistance, weather resistance to heat and cold, and allow painting to match the color of the roof. They do not require any additional fasteners and can be applied on wet or dry surfaces.
Designers often are faced with the need to restrict wind-driven moisture at the openings. There are now pre-bagged mortars that are easier to mix and non-shrinking by design. These alternative mortar options can reduce the breakdown or loss of bond to the roof claddings from shrinkage. There are also flexible mortars that come prepackaged and even pre-colored that will have the ability to stretch during expansion. By incorporating these products in roof designs, architects can reduce the long-term maintenance and increase the roof performance. In many cases the slight increase in the design for installation will be offset by a greater long-term life cycle cost reduction from decreased maintenance and call backs by your roofing professional. The upcoming WSRCA show in September will be a great way to connect with many of the manufacturers to discuss the merits of these products on your next design.