[RE-wrenches] Mounting to metal roofs and thermal expansion

[jay peltz]

Hi Troy,

I don't know what to tell you, pretty scary to me to cut a big hole in  
the metal roof.

I'm curious about any links you have to those mounting systems?

thanks,
jay

peltz power
On Feb 7, 2009, at 11:24 AM, Troy Harvey wrote:

>
>> You don't screw the roofing pans down through the pan, they are all  
>> held down with some kind of clip system; there are no roof  
>> penetrations, as the hold down screws are under the roofing.
>
> I'm not talking about seam clamps at all. But using a boot flashed  
> stand-off foot.
>
> We looked at S-5! clamps, but they aren't rated for many types of  
> metal roofs. So we are going to use a Unirac stand-off foot lagged  
> through the pan into the roof, with a rubber boot flashing. However,  
> I'm concerned about the impact of fixing the roof in the middle of  
> the pan with the lags on the foot constraining thermal expansion  
> after seeing a European mounting foot system that they use a grinder  
> to cut a hole in the metal roof, lag to the sheathing directly and  
> use an overlapping rubber seal so the roof can move independently of  
> the mounting foot.
>
> Has anyone had problems with thermal expansion and mounting feet  
> lagged through the roofing pan?
>
>
> Troy Harvey
> ---------------------
> Heliocentric
> 801-453-9434
> taharvey at heliocentric.org
>