[Greenbuilding] ***SPAM*** Re: ***SPAM*** Steel Roof Question

[Lynelle Hamilton]

Hi Peter,

MANY thanks for the references. The issue is the roof ventilation and 
that there is no air barrier. My contractor insisted that the purloines 
would provide venting.and that no barrier is needed. He's wrong on both 
counts, but refused to listen.. He's coming around to removing the steel 
panels and installing the air barrier at his cost, plus ensuring 
ventilation channels, but the articles you cite below will help.  He's 
generally a good guy (and has owned a roofing company that mostly did 
flat roofs and commercial) so I think genuinely believed that his 
install was OK. He is learning a rather expensive lesson, though.

Thanks again!

Lynelle

On 2024-01-09 6:30 p.m., Peter/Pam Martin wrote:
> Hi Lynelle,
>
> I am no expert but the contractor's advice appears untenable to me. I 
> think you are in climate zone 6. Is the roof vented or unvented? Where 
> is the roof air barrier? Is it continuous with the wall air barrier?
>
> Hopefully you may glean some information from the following articles:
>
> https://buildingscience.com/documents/insights/bsi-046-dam-ice-dam
>
> https://www.erdc.usace.army.mil/Portals/55/docs/CEERD-RV/CEERD-RR-H/BuildingTechnology/ResearchPapers/MP-02-5778,%20Guidelines%20for%20Ventilating%20Attics%20and%20Cathedral%20Ceilings%20to%20Avoid%20Icings%20at%20Their%20Eaves.pdf 
>
>
> https://buildingscience.com/documents/insights/bsi083-mea-culpa-roofs
>
> Other good articles to link to at https://buildingscience.com/
>
> All the best,
> Peter
>
> On 1/08/24 6:50 a.m., Lynelle Hamilton wrote:
>> Hope y'all are still out here!
>>
>> I have contracted with someone for an addition to my home. The 
>> addition has a second story with a cathedral roof. The contractor 
>> insisted that I did not need decking and ice/water dam on the 
>> rafters, so installed the purloines directly on them, then installed 
>> the steel roof.  I have installed 3 steel roofs, but never one this 
>> way, so questioned it.  He insists it's the correct method.
>>
>> To meet the Ontario Building code, he said we had to lay 2 layers of 
>> R14 insulation, then install  foil-covered foam board (foil both 
>> sides)on the inner side, seal and tape. I used Rockwook, plus RKO 
>> 3/4" board as per his specs. We have not yet installed drywall.
>>
>> There are at least 10 areas of trapped moisture in a 16x47 foot area. 
>> One is dripping onto the first floor
>>
>> We pulled the insulation from one area and found significant 
>> condensation on the cold steel roof, seeping through the Rockwool and 
>> running down the cold side of the foil covered foam board. The 
>> contractor says this is due to latent moisture in the insulation and 
>> that we've got propane heat in the basement. He says it will resolve 
>> in time.  I don't buy this.
>>
>> Any advice is appreciated.
>>
>> Lynelle Hamilton
>>
>>
>
>

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