Lazy Daze Owners' Group

Solar Panels - correction

January 22, 2001, 09:09:25 am

Yahoo Message Number: 1727

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I earlier posted that the only concern that came to mind regarding a problem with installing solar panels to the wood skin under the aluminum was the differing expansion rates of the materials. This statement was shortsighted and basically incomplete. At the time I originally considered installing PV panels, I looked at the issue more closely, and there IS a far more important issue.

Lazy Daze roof and wall construction basically sandwiches a wood stud framework between thin sheets of plywood, this structure providing strength and a high degree of torsional rigidity in all planes. The fasteners, whether screws or nails, that hold the sheets to the studs, are designed and placed to maximize lifetime contact between the two, and to provide a large part of the shear strength of the structure. They are not designed to withstand longterm forces pulling on them axially, i.e. attempting to pull the wood sheets off the studs.

Using the sheets as attachment points for supporting accessories on the roof, as with solar panels, will have some tendency to do just this. Although the panels are lightweight, they do have some mass, and can be subject to lifting forces when driving, so this is a concern. Over time, it is possible that with some such installations, the underlying panel's attachment to the studs will be loosened sufficiently to allow a small amount of increased flexing of the roof, giving rise to sqeaks.

That said, I took this into consideration when siting our panels. Given our previously crowded roof, there were not a lot of options anyway, but mounted between the air conditioner and evaporative cooler, two items bolted solidly through the wood sheets and into the supporting framework - I have no concern that loosening of the wood sheets is an issue for us.

I suggest that anyone contemplating adding solar panels decide for themselves whether they are comfortable with a 'non-Lazy Daze' installation, else have the factory do the job and guarantee the result. I would still never consider any installation which fastens them only to the aluminum skin unless the factory will warranty it.

Steve

SOLAR PANELS

Reply #2 – January 23, 2001, 12:14:04 am

Yahoo Message Number: 1754

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Solar panels will have only a fraction of their rated output on a cloudy day. Even a small shadow on part of a panel will have a similar effect. If mounted flat on the roof, output also drops dramatically if the angle of the sun above the horizon is low. I doubt if Sitka is a good candidate.

Steve