[RE-wrenches] anchoring racks to concrete roof

[Ken Schaal]

Hi Jay

I have experience with similar structures. Is this a Monolithic Dome?   Key 
Dome?

In any case, with 2.5 " of concrete, it almost certainly has welded wire or 
rebar or both embedded, so you have lots of strength. Just need to get lucky 
when you drill holes to miss the metal. No need to go deeper than 2", if the 
previous is so. You're on the right track with epoxy filled so you maintain 
water tightness.
What is the coating on the exterior concrete?

Ken at commonwealthsolar.com


----- Original Message ----- 
From: "jay peltz" <jay at asis.com>
To: <karl at northwindre.com>; "RE-wrenches" 
<re-wrenches at lists.re-wrenches.org>
Sent: Wednesday, February 11, 2009 10:36 AM
Subject: Re: [RE-wrenches] anchoring racks to concrete roof


> Hi Guys,
>
> This mount install is not on a flat roof, well a few hundred sq feet  are, 
> but mostly on some tilt.
> Also they do get hurricanes there, so not sure how well the ballasted 
> work in that high of wind.
>
> As to the construction, not of my choice anyway.  I've never see in  here 
> in the US but in MX or Baja at least its common.
> Quicker than standard blocks and lots of insulation in the middle.
>
> So I think I really looking at in concrete anchors, and am leaning 
> towards epoxy style.
>
> Thanks,
>
> jay
> On Feb 11, 2009, at 6:11 AM, Karl Schwingel wrote:
>
>> Hi Jay,
>>
>> not having any experience with these roofs (what a weird way to  build a 
>> roof) if you're doing a flat or near flat mount, I'd look at  the 
>> currrent issue of Solar professional magazine.  lots on flat  roof 
>> mounts.
>> Ballasted is probably going to be your best bet.
>>
>> if a high tilt (hot water system? )  I'd recommend either core  drilling 
>> thru the concrete/foam sandwich and bolting a pipe leg to  the bar truss 
>> underneath.   then have a roofer (roofer of record if  you can find them) 
>> or a roofer with experience with that roofing  system flash the pipe 
>> legs.
>> I'm mostly hot water, and so deal with higher tilts and wind loads  than 
>> most of you lucky PV guys.
>>
>> Karl
>>
>>
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