[RE-wrenches] L feet no flashing in shingle roof

[Chris Mason]

I've never had that luxury, generally the underside is visible and can't be
changed. We get through but it's a pain.

On Wed, Jul 4, 2012 at 8:36 PM, benn kilburn <benn at daystarsolar.ca> wrote:

> Chris,
> I'm pretty sure that what David means by "blocking" is if the roof has
> rafters (peak to eave) rather than purlins (horizontal) then, IF you can
> access the underside of the roof, you properly install 'blocking' (2x4,
> 2x6, 2x8) against the underside of the roof sheathing, perpendicular to the
> rafters.  Then you can drill your bolt anywhere along the blocking which
> then eliminates the restriction of having to attach to a rafter every
> 16-24".  Keep in mind that there are proper methods of doing this to make
> sure the blocking is properly attached to the rafters, otherwise any uplift
> pressure from the array is only supported by the roof material and not the
> structure (rafters/purlins)
>
> Then again, access to the underside of the roof is not always available or
> is restrictive, so this is an important factor to figure out before you
> land on site with your roof attachments and racking, ready to go.
>
> Cheers,
> benn
>
> DayStar Renewable Energy Inc.
> www.daystarsolar.ca
> 780-906-7807
> Construction Electrician Solar Photovoltaic Systems Certified
> Certificate # 0007S
> HAVE A SUNNY DAY
>
> On 04/07/12 5:23 PM, "Chris Mason" <cometenergysystems at gmail.com> wrote:
>
> I use corrugated mounting bridges - that's the problem. If the center of
> the beam falls in the trough, the corrugated bridge is useless.
> I am not sure how blocking would help. Corrugated is a pain.
>
>
>
> On Wed, Jul 4, 2012 at 12:11 PM, David Brearley <
> david.brearley at solarprofessional.com> wrote:
>
>> In some cases, you can install blocking to get up on the ridge
>> consistently. One alternative to hangar bolts is to use corrugated mounting
>> bridges from DPW Solar or something similar from another company.
>>
>> Sorry I can't link to the PDF. Google: "corrugated mounting bridges"
>>
>> Since exposed-fastener metal roofs already have a bunch of holes in them,
>> you're not voiding the roof warranty by punching more holes in the ridge.
>> (I don't think these roofs even meet the NRCA definition of a "roof
>> assembly" because of the exposed penetrations.) Penetrations in the valleys
>> on a roof are problematic for obvious reasons.
>>
>>
>> On Jul 4, 2012, at 6:01 AM, Chris Mason wrote:
>>
>> > All of this refers to shingle roofs, which we don't see much of. We
>> mostly deal with concrete and corrugated steel/galvalume, the latter being
>> a nightmare. Does anyone have good ideas for dealing with corrugated?
>> There's no way to flash it, the blocks are fine when you hit a beam on the
>> ridge but half the time your penetration has to be on the trough of the
>> corrugated steel.
>> > Other than lots of goop, I don't know how else to seal it.
>>
>
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-- 
Chris Mason
President, Comet Systems Ltd
www.cometenergysystems.com
Cell: 264.235.5670
Skype: netconcepts
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