Federal Way Roofing: Article About Shingle Overlay Disadvantages
When homeowners look at an old shingle installation, the idea of simply covering it with new shingles seems like a smart choice. Two shingle layers would seem to greatly enhance roof leak protection, but this concept is not accurate. A Federal Way roofing professional can explain all the disadvantages to a shingle overlay project so that residents can choose a long-lasting new installation instead.
Overlaying old shingles with new materials gives rise to lifting issues. Because of surface anomalies across the old shingles, the new installation doesn't lay completely flat. As winds rise up, new shingles can get caught in strong breezes. Shingles could begin to lift and curl, causing potential water leaks into the home. Roofs without overlays remain flush with the roof deck for years of material stability.
When a brand-new shingle installation is in progress, roof weight isn't a big consideration because a single material layer is relatively light. Almost any roof can hold a single shingle layer, even with possible snow accumulating on it part of the year. However, overlaying shingles bring roof weight into real consideration. Older buildings may not hold the weight well, contributing to possible structural failure over time.
One of the most important parts of shingle projects is professional inspection of the roof deck.
The roofing experts at Chase NW of Federal Way WA can assist you with any questions regarding commercial roofing or roof inspection.
This deck is made primarily of plywood and support beams below. With all the shingles removed, any cracks or missing sections can be repaired. Even roof penetrations are checked at their connection points when the deck is exposed. When a shingle overlay is chosen, there is no chance to check the roof deck. A home goes without proper inspection and may succumb to more water leaks in the future.
Along with roof deck vulnerability, shingle overlays also prevent new underlayment from being installed. Also known as roofing felt, this underlayment breaks down over time as it rests between the deck and shingles. Professionals should roll out brand-new underlayment to protect the deck while providing another layer against moisture infiltration. Repairing a home from water damage is more costly than choosing a shingle removal and installation strategy.
Aside from all the practical reasons to avoid shingle overlay, homeowners should also note that the final product isn't as aesthetically pleasing. Extra shingle layers create a bulky appearance, especially at roof eaves where edges are most prominent. A smooth and precise new shingle installation is suited to a promised warranty of 20 to 30 years in most cases.