Roofing FAQ

Q:
I have one layer of shingles on my home which need to be replaced. Is it necessary to remove these shingles prior to the installation of a new roof?
A:
The building code permits you to go over existing shingles with a second layer, but it is not recommended. Although cost effective, faster and cleaner, the possible problems in leaving the original layer on the roof outweigh the benefits. Most roof decks constructed in the last 40 years are made of 3/8" plywood with truss supports centered at 24". Although adequate, this roof design does not support additional long term weight loads, (such as a second layer of shingles). The most common result is sagging between the trusses, creating a unattractive rolling effect. In some cases, the actual trusses may warp. As well, the gaps and air spaces between the two layers create a softer surface, which generally causes the shingles to age faster. The underlying shingles often reflect through the new layer, resulting in an unsightly appearance. Without removing the original layer of shingles the roof deck cannot be inspected for any repairable flaws or decay. Finally, a suitable underlayment cannot be applied to offer sufficient winter and storm protection. The removal of the shingles may add 25% to the overall cost of roof replacement, but the added life, superior performance and improved appearance of this application more that justifies the additional expense.  

Q:
What are 'Architectural Shingles' and why should I consider them for my home?
A:
Architectural shingles are an asphalt shingle that is manufactured to provide a thatched, 3-dimensional appearance, similar to traditional wood or slate shingles, but at a fraction of the cost. The process usually involves the lamination of one shingle over another resulting in a heavier, longer lasting product with more curb appeal than a traditional 3-tab shingle. Typical warranties on this product range from 30/40 years lifetime. Homeowners looking for added durability and/or increased resale value should seriously consider this low-cost upgrade.

Q:
Last winter our roof leaked due to excessive ice damming along the eaves, causing considerable interior damage. Why did this happen and how can we prevent this from reoccurring?
A:
Ice dams generally form after a heavy snowfall, followed by an extended period of freezing weather. Homes that are poorly insulated and/or under ventilated are more prone to this problem. Heat escaping from the house warms the attic space, particularly along the wall line, where the attic space is small. As the roof deck warms from the attic, snow melts and runs down the roof, refreezing over the unheated soffit area. This thawing/freezing effect causes ice to build up and roll into the eaves, eventually creating a dam to further melting snow, trapping water and forcing it under the shingles, creating an interior leak. SOLUTIONS a. Increasing the attic insulation decreases heat loss into the attic and minimizes the thaw/freeze cycle that forms the ice dam. b. Increase ventilation in both the soffit and the roof deck allows dry cool air to flow into the attic and hot moist air to escape, again preventing the thaw/freeze cycle. c. Roof underlayment can prevent leaks, if an ice dam still occurs. Edmunds recommends a peel and stick membrane, such as the IKO Stormtamer membrane on the bottom three feet, essentially sealing water out, plus a synthetic membrane over the remaining roof for added security. d. Heating cables, as a last resort, provide a bandaid solution by preventing ice from forming along the soffits and eaves. It should be noted that this product does not address the underlying problems. (i.e. poor insulation/ventilation).      

Q:
How do I know when it is time to replace my roof?
A:
If your roof is 10 years or older, look for these trouble signs: NOTE:Southern and western exposures usually age quicker, as do lower pitched roof areas. If unsure, Edmunds can provide a free assessment.