AboutBrad Zacharia Expertise All aspects of residential Roofing. This includes shingles and flat (low slope) roofs. I have knowledge in the installation as well as the design of roofs from an engineering standpoint.
Experience I have been doing roofing for 40 years. This was my father's business and I took it over in 1980.
Publications I have written responses to artcles that I felt needed a response to and those responses have been published in roofing trade magazines.
Education/Credentials BSEE Drexel University
www.ZachariaRoofing.com
Question QUESTION: If I get rubber, running it up the sidewall sheathing 18” (as roofer recommends) would keep the water out, but will look pretty crummy unless vinyl siding can be re-installed on top of the membrane, and then wouldn’t the starter strip or j-channel’s nails (at the bottom of the vinyl) have to penetrate the rubber membrane? If instead I get steel standing seam (roof slope is partly 2:12, partly 4:12, so maybe OK), how should this same junction be flashed?
Thanks very much for your help.
ANSWER: Yes, the siding would make holes in the rubber but the siding should itself be waterproof so why run the rubber underneath it in the first place. Siding keeps water out on walls and rubber keeps water out on roofs. What am I missing here?
Brad
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QUESTION: The roof doesn't slope away from the wall, but along the wall, thus the roof-wall junction seems like a vulnerable spot for water penetration (especially when snow piles up there). Running the rubber up onto the wall would deal with that, but would be ugly, unless the siding covers it up. But re-attaching the siding will puncture the rubber, and lead to leaks, says the rubber roofer. The metal roofer proposes a metal flashing strip slipped (barely) under the vinyl, screwed to the wall, and lapping over the side of the metal roof panel as it come down the slope. This would look nicer, but seems to rely heavily on the underlayment to keep water out. For either method, the question is how well a fastener penetration can be sealed.
Thanks.
Answer Run the rubber up the wall about 12". Then start your siding about 4" or more into the rubber. Yes, the siding will make holes in the rubber but the nails are behind the siding and water should never get to it. Water will run down the siding and off the bottom of the J-channel and onto the rubber. The water will never see a nail. The water from the snow will melt and run down- not up behind the siding. The water flow will be down by the roof line. Dong anything else there will leave you vulnerable with holes. Since this is a low slope roof it will not be easy to see the roof since it mostly faces the sky.
