Solving Ice Dam Problems

Utah Ski Resort Solves Ice Dam Woes

by Paul Batt, CertainTeed Corporation


From Western Roofing Sep/Oct ’11


The mountainous region of Northern Utah provides ideal conditions for skiers; cold air, heavy snows, clear blue skies, and plenty of picturesque slopes to speed down. The heavy snows can, however, be rough on homes and buildings, especially their roofs. Snow accumulation on roofs without adequate insulation or ventilation strategies can create ice dams, which over the years can lead to a variety of structural damages, such as roof leaks, wet and ineffective attic insulation, stained or cracked plaster or drywall, or rotting roof trusses. These were the kind of problems the nationally renowned Deer Valley Ski Resort in Park City, Utah, was experiencing with the roof of one of its ski lodges.

Last year, Deer Valley Ski Resort’s Royal Plaza Lodge, which houses corporate offices for the resort and offices for some of its primary shareholders and owners, was 25 years old and ready for a complete renovation of exterior finishes, which would include new siding, new windows, and a new roof. Ice dams were a constant winter-season problem and had gotten worse as the lodge grew older.

Ice dams are a common problem in ski country and are partially related to the architectural style of most ski lodges, according to Dave Stevens, director of building maintenance for Deer Valley Ski Resort. “We’ve put ourselves in this position by building all of these lodges with pitched roofs with multiple valleys,” Stevens says. “Unless you have a good roofing ventilation strategy, you’re going to have ongoing problems with ice dams.”

Deer Valley Ski Resort hired WPA Architecture, based in Provo, Utah, to design the renovation and Cambridge Builders and Roofing, of South Jordan, Utah, to install new roofing and siding. To address the ice dam problem, the team agreed on a cold roofing system, which ventilates the roof, keeping it cold and preventing warm interior air from melting accumulated snow and creating ice dams. The key component of this roofing system was CertainTeed® FlintBoard(TM) CV polyisocyanurate roof insulation.

CertainTeed FlintBoard CV is a rigid board insulation specifically designed for use over sloped, unventilated roof decks to provide thermally efficient insulation with uniform cross venting that promotes the air circulation required by many shingle manufacturers. The product is available in 4’ x 8’ panels that consist of a layer of 7/16’’ oriented strand board (OSB) and a layer of polyisocyanurate board with a ventilation space in between the two. This configuration allows heat to dissipate while providing a nailable surface and efficient insulation in a one-step process. The FlintBoard CV panels used on the Royal Plaza Lodge project had a 2’’ ventilation space for maximum cross ventilation.

Cambridge Builders and Roofing installed the insulation panels in the fall of 2009 over a non-vented wood roof deck. This was followed by a layer of CertainTeed WinterGuard Waterproofing Underlayment over the OSB side of the panels and approximately 120 squares of CertainTeed Presidential Shake(TM)TL luxury shingles. The new roof and the remaining portions of the exterior renovation were completed just in time to be tested by the oncoming winter season.

Royal Plaza Lodge’s cold roofing system easily passed the test of its first winter, while it also met Deer Valley Ski Resort’s aesthetic needs. “We had no ice dams last winter, so the CertainTeed cold roofing system is working well for us,” Stevens says. “And, the shingles give the roof a nice, colorful wood shake-style appearance. We’re very pleased.”