What can the roof support?

[Benign Vanilla]

I am thinking of adding solar hot water heat to the house someday, and I was wondering how I go about determining what kind of weight my roof can support? The house is a truss frame construction. There is a set of horizontal joists for the sheetrock, then a set at about a 30 degree angle, and then another set at maybe an 80 degree angle. All of this is framed with

2x3's not 2x4's.

BV.

[DaveG]

Have a talk with your city or county or whoever issues building permits in your area. Our city has engineers on staff to assist with questions of this type. They helped me determine the load capacity of my deck, so I'm sure they'd have done similar on the roof if I'd have asked.

[Benign Vanilla]

Thanks.

BV.