We are building a new home off a cliff that is 25 feet off the river. We are getting qotes that have different ways of installing the singles. Can you help us out with a few questions. How many feet do we need of "ice and watershield" from the bottom edge of the roof. Some say 6 feet and others say 3 feet. Where the gables are some are saying up to 9 feet. Should we have "felt paper" on the balance of the roof? Then we have the question of what type of vents do we need to use?
Answer:
A good system of shingling entails ice & water shield installed along the lower edge of each roof panel. This shield has to go up high enough to be at least nine inches past the exterior wall of the house or whatever structure there is under it (if this happens to be a 'low slope' roof, the ice and water shield goes up to within a couple inches of the peak). Black, 15-pound building felt is then installed horizontally on the remainder of the roof to within a couple of inches of the peak before shingles are applied. At the peak, there should be a baffled ridge vent running from gable to gable on straight runs and from the gable back to within a couple of feet of valleys if they exist. In the case of a cottage roof, this system will give you more efficient ventilation than any other. The valleys themselves should also be amply lined with ice & water shield under whatever metal flashings there may be. The chimney, if it needs attention, should be addressed before any of this starts. The twenty-year asphalt shingle is presently the most cost effective product on the market.
