Greenovision consults on re-roofing project
In addition to designing new homes, additions, and remodels, Greenovision Home Design offers third party hourly consultation on home-related construction projects and home energy improvement. Mark Pelletier’s contracting, construction, and design experience allows us to offer practical and efficient advice with affordability in mind.
In the fall of 2015, Greenovision offered consultation on the re-roofing project of a summer cabin (not a Greenovision design). The cabin and original asphalt shingle roofing were 20 years old and the roof was leaking at the transition between the two different roof pitches (where the main roof met the roof over the porch). Because of the low pitch of the porch roof and the friction of the asphalt shingles, snow and ice were building up on the roof transition during the winter and were not properly sliding from the roof. Spring freeze/thaw cycles were causing water to creep under the shingles and leak through the porch roof. Additionally, moss was growing on the shady porch roof, which pried up the shingles and allowed for water infiltration.
The homeowner was initially thinking that perhaps a new roof of a steeper pitch should be framed over the existing porch roof to allow the snow to shed better from the roof. Then, new asphalt shingles would be nailed to the new roof. We suggested, however, that a better approach would be to re-roof with standing seam metal roofing. A metal roof would achieve many things: 1) Snow and ice would easily shed from the porch roof, even at its low pitch; 2) A new roof would not have to framed over the existing porch roof, saving costs on construction labor and materials; 3) Moss would not continue to grow over the asphalt shingles; and 4) The metal roof would last over 50 years, which saves money and materials, as opposed to re-roofing with asphalt shingles every 20 years.
When we spoke with the metal roof subcontractor over the phone, he suggested that the metal panels could be applied over the existing asphalt shingles without removing them. Since the homeowner was going through the expense of the project, we suggested the project be done correctly now so that the new roof would last as long as possible. Therefore, we requested that the roofer remove the existing singles and tar paper before re-roofing with a new water barrier and the metal roofing. That way, any possible rot in the plywood would be exposed and repaired before the metal was laid down, plus the weight of of the roof would be reduced by removing the shingles.
In spring of 2016, when the re-roofing project commenced, everyone involved in the project was very happy that the asphalt shingles were removed because it was discovered that the entire porch roof was rotten and the roofers were falling through in some spots. Every piece of plywood over the porch had to be replaced with new OSB. If the asphalt and rotten plywood hadn’t been removed, the moisture and mildew would have been trapped under the new metal roofing and the rot would have eventually crept into the interior of the porch, exacerbating the original problem. In the end, the homeowner is glad to have a new roof that doesn’t leak and will last over 50 years and feels that the cost of the project was money well spent. We at Greenovision feel that the new color and material of the roof really helps to beautify the summer cabin and we love the result.
If you are embarking on a home-related project and have questions or need advice, please email us to schedule a consultation. We offer practical advice on methods and materials, as well as longevity, affordability, sustainability, and energy-efficiency.