About Mark Sundberg Expertise Architecture, structure, construction.
Experience 27 years licensed architect, work in 12 states. Currently working in Hawaii. Over 1000 buildings designed or worked on in a significant role
3 years quality control officer for Navy construction projects.
Education/Credentials Bachelor of Architecture, Cal Poly, San Luis Obispo, CA. 1977.
I have a metal flat roof (1 1/4" per foot slope). The metal looks like it 12" by 18 or 24" sections fastened together. Hard to tell from the number cover coatings painted onto it. The last several being that aluminum roof coating. I can see all the location of joints through the coating. Needs to be re roofed. Started leaking this winter and I sealed the areas with roof cement.
Also the previous owner, some 20 years ago, drywalled the ceiling after stuffing it with fiberglass insulation. No ventilation but no signs of moisture. The roof is on an 20' by 12' bedroom addition added 80 years ago.
I was told to just put roll roofing over the existing roof. I worry about moisture building and being trapped under the roll roofing. Any economical solution ideas? Image attached- you can see the outline of the metal roofing
Thank you.
Answer Hi Mike,
Yeah, those older style metal roofs, comprised of small panels, are not all that good these days, though when they were installed when people took the time to do it right and soldered the joints well, they were pretty good. Just like I've been in old barns with 80 year old cedar shake roofs you can see daylight through, but not a drop of water comes through, even in heavy downpours.
I would suggest following the advice given, to go with a good basic roll roofing, though I wouldn't suggest overlaying on the existing roof. It will be economical and if carefully installed, will give you good service. Make sure you follow the manufacturer's instructions to the letter.
As for the attic space, is this just the space between the rafter/joists or are there separate roof and ceiling joists? If the former, well, you can try to get some ventilation in by drilling some holes in the blocking on both ends of each space, if they are on the outside walls, and install some of the round louvered vents. It may not help loads but it will be something.
If it's the latter, with a bonafide attic space, you may want to consider a turbine vent as well.
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