Hi All,
I need to install solar panels on roofs, on a regular basis. My problem is, I need to hit the rafters under the shingles (darn narrow). I haven’t been able to find a detector that works on roofs, or any other way to make this easier without dismantling the roof. Drilling a hole through the roof, near the rafter is not a good practice. Does anyone know of a device that “sees” rafters under shingles? Or any other techniques that work in this situation?
Thanks.
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Replies
Would this work? "The TriScannerâ„¢ Pro, with its three different settings, will find copper pipe as well as wood and metal studs to a depth of 1-1/2" and rebar to 3" in materials such as concrete, drywall and most floors. It also detects "hot" (unshielded) electrical wires."
http://www.leevalley.com/wood/page.aspx?c=1&p=32547&cat=1,43513,43540
The problem with most stud detectors, even the most sophisticated ones, is that they usually need a homogenouous material to work properly. With shingles, you have layers of materials with air in between the layers, and then nails in the plywood. All these throw off even the best detectors most of the time. Reliability is another issue that we've been facing. A certain detector may work at times, but not always, so it's still a hit-and-miss.
Thermograph?
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Never heard of something like this... Can you indicate a brand/model that you've had good experience with? Thanks for the suggestion, anyway.
look at professionalequipment.com
look for infrared thermometers tooThe thermograph is a pho0to map of heat but expensive. maybe worth it if you do this daily. The thermometers are handhelds with meter displays
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When you first mentioned "thermograph" I did a search which pointed me toward "infrared cameras" and infrared thermometers. The cameras are indeed expensive, a medium-featured around $10k, and a good one around $26k.
For my application I think that a simple infrared thermometer (around $100) is good enough. Funny thing is that I had such a thermometer all along, only never thought of using it for detecting rafters! Can't try it right away 'cause there's about a foot of snow on roofs in my area, but I'll give it a try in spring. I'm thinking that if the temperature differential (between rafter or no rafter) is not enough for the thermometer's resolution, to "help" it by placing an electric heater in the attic; this should magnify the difference, making it more accurate to pinpoint the added insulation provided by the rafter. What do you think, will this work?
Just practice to discover which tiem of day is most efficient for readingsNow that you've got what you're looking for, how's about filling us in on what you do and the future of the solar industry? It's good to have technicians and installers here from all the trades.
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Piffin,
I'll let you know how it went, after the big test. The solar industry? Big hopes, we want to put a unit on everyone's home. The future is all rosy, but then again we're all dreamers and biased. I'm in the "thermal solar", not the photo-voltaics. Less glamorous, much more efficient. I wouldn't consider it a trade in itself: it's like being a plumber but working on roofs.
now there's a paradox for me. A solarguy who is a plumber...I just have to look at plumbing to make it leak, but i spent over twenty years on roofs stopping leaks.
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Don't need a thermagraph. All you got to do is look at the roof early morning when the sun hits it and there's a light frost. The way some homes are poorly insulated the rafters will be where the frost first melts.
Poorboy thermo!
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Drive a nail through the deck from below, right next to a rafter. Patch hole when done.
You forgot to tell him to measure centers while he was in the attic. He could find the rest of them with his tape measure from the nail sticking up though the shinlges.
Dave
Well, I thought about it, but I didn't want to insult anybody's intelligence. I figured anybody who's paying attention would know that, and anybody who's not paying attention deserves to patch several dozen holes.
Gee..this thread is akin to putting on make up before going into prison...holes? what holes?
Spheramid Enterprises Architectural Woodworks
Watch out for the edges, it's really fast out there...
I actually need to hit the dead center of the rafters (only 1.5" thick)! As confirmed to me by experienced roofers, the rafters are not placed with swiss watch precision, plus you have rafters that bow. So the simple tape measure/ use your brain thing doesn't quite work. I know it's a weird problem to have, and there's not much experience out there with this: who other than solar people need to attach things to the roof (accurately). In addition, I don't specifically like the idea of poking holes in people's roofs just to see where the rafters are - I've used this method but I'm trying to find something better!
To increase you chances of hitting a rafter, and you have a general idea where you want to mount the hardware, why not sister a 2x4 tight to the sheathing? Doesn't have to be the total length, just long enough to ensure you cover the panel length. You've doubled your target area.
Just an idea.
I never met a tool I didn't like!
The idea is not bad, and is doable if I was to only install once. However I'm trying to increase productivity here. Think many homes, and think a project that requires hundreds of solar panels, each requiring about 8 anchor points. That's a lot of sistered rafters. I'm not pulling your leg, but seriously I'm looking for the BEST solution, not just any solution.
But that was the best. At least the best that I could come up with : )
Confusious says, to find the pearl, one must be prepared to sift through an ocean of oysters.
Actually, I haven't a clue if he said that or not, so I'm taking the credit.
I never met a tool I didn't like!
I'm prepared to sift through the oysters, especially if they're edible...
I haven't found a stud sensor that is very reliable especially through wood with nails.
If there is a ridge vent, you may be able to get a peek inside without making a major repair.
You may also be able to look up through soffit vents. Look for nails in the fascia, they are often on rafters. Sometimes you can lift the drip edge just enough to see either rafter tails or where the sheathing is nailed. You may get pretty close just by tapping with your hammer, you can feel the solid rafter compared to bouncing plywood.
An inch and a half is tough to hit dead center. Your mounting brackets must be wider than that. Can you use heavy molly bolts or expansion anchors just in case you miss? It isn't always easy to access an attic but you can add blocking if you can get up there.
Beat it to fit / Paint it to match
Thanks, Hammer. Yours is by far the best reply I got so far. You understood the difficulty. We've used both the hammering method (souds different above a rafter), and the nail near the rafter from the attic. The former is not especially accurate, and the latter is time consuming and less "elegant", i.e. you put an unnecessary hole into the roof. To compound the difficulty, there are rafters that are not exactly straight, so measuring is also not always giving good results.
I'll try your other suggetions...
Most of us can't hit a 2x even if we know where it is. Here is a picture of some fasteners and an installation tool. The tool is by Goldblatt #09970. You may find heavier fasteners at your local supplier, around here I use K.L. Jack or Reliable Fastener. I think the sheathing will be pulled off before the fastener fails, especially if you are close to a rafter. They come in a variety of neck lengths for different thicknesses.Beat it to fit Paint it to match
Just look for the peaks between the dips in the OSB. Or observe the frost pattern on a cold day.
If you were working with something like an asphalt shingle, not to brittle, and can get your putty knife under it and carefully bend it up.... drive three nails in together. Now, go into the attic(if theres access) and look for your three nails. Measur over to your nearest rafter. There. Don't know what you'd do with something like slate.