Hello
I have a metal roof in a barn that is going to be converted into an apartment. Currently, there is no form of condensation protection on it. I plan to remove it and install proper roofing felt underneath, re-batten, and then put the metal back again with new fresh screws with rubber gaskets...
I'm considering using MONARPERM 900 from Icopal or Tyvek Supro Grid as the underlay roof to then apply counter battens and slightly thicker battens, finally placing the metal roof again. There's no need for an air gap against the insulation, which in this case is spray-applied cellulose fiber.
Does anyone have experience with something similar or anything to add/comment on?
The alternative is of course wind deflectors/fabric, air gap, roof sheathing, roofing felt, battens, and the metal again....
The roof is about 180 square meters with a 34-degree slope.
Also trying to figure out what is cheapest, besides being the fastest. I haven't found prices/suppliers for Tyvek. I believe the Icopal variant costs about 60 SEK per square meter.
More info at: http://www.icopal.se/upload/Product...72A5006AE285/Icopal_broschyr_Monarperm900.pdf
and
http://www.profile.dk/www/Pub1695.asp
I have a metal roof in a barn that is going to be converted into an apartment. Currently, there is no form of condensation protection on it. I plan to remove it and install proper roofing felt underneath, re-batten, and then put the metal back again with new fresh screws with rubber gaskets...
I'm considering using MONARPERM 900 from Icopal or Tyvek Supro Grid as the underlay roof to then apply counter battens and slightly thicker battens, finally placing the metal roof again. There's no need for an air gap against the insulation, which in this case is spray-applied cellulose fiber.
Does anyone have experience with something similar or anything to add/comment on?
The alternative is of course wind deflectors/fabric, air gap, roof sheathing, roofing felt, battens, and the metal again....
The roof is about 180 square meters with a 34-degree slope.
Also trying to figure out what is cheapest, besides being the fastest. I haven't found prices/suppliers for Tyvek. I believe the Icopal variant costs about 60 SEK per square meter.
More info at: http://www.icopal.se/upload/Product...72A5006AE285/Icopal_broschyr_Monarperm900.pdf
and
http://www.profile.dk/www/Pub1695.asp
Last edited:
Addition from http://www.byggfaktadocu.se/10/pdcnewsitem/00/95/06/index_10.html
"- The roofs have avoided moisture damage thanks to the DuPont Tyvek Supro Grid underlay's diffusion-open properties, which allow drying outwards!"
SP, the Swedish National Testing and Research Institute, conducted moisture measurements on March 7, 2000, in three roofs on buildings in Norway. All houses were fully insulated between the roof beams and with DuPont Tyvek Supro Grid as the underlay. DuPont Tyvek Supro Grid is a diffusion-open underlay that allows the roof beams to be fully insulated all the way up to the underlay, excluding outside-ventilated air gaps.
Now, seven years later, SP has conducted a follow-up on the previous study, and their conclusion is:
"- Despite the houses having overpressure, significant moisture addition, and deficiencies/leaks where humid indoor air could leak out into the roof structure, no indications of moisture damage were found.
Additionally, the measurements were taken during an unusually humid outdoor period, which also explains the high moisture values in the battens and counter battens. Generally speaking, moisture damage can be expected in roofs with the above-noted deficiencies. Our assessment is that the roofs have avoided moisture damage thanks to the diffusion-open properties of the underlay, which allow drying outwards."
"- The roofs have avoided moisture damage thanks to the DuPont Tyvek Supro Grid underlay's diffusion-open properties, which allow drying outwards!"
SP, the Swedish National Testing and Research Institute, conducted moisture measurements on March 7, 2000, in three roofs on buildings in Norway. All houses were fully insulated between the roof beams and with DuPont Tyvek Supro Grid as the underlay. DuPont Tyvek Supro Grid is a diffusion-open underlay that allows the roof beams to be fully insulated all the way up to the underlay, excluding outside-ventilated air gaps.
Now, seven years later, SP has conducted a follow-up on the previous study, and their conclusion is:
"- Despite the houses having overpressure, significant moisture addition, and deficiencies/leaks where humid indoor air could leak out into the roof structure, no indications of moisture damage were found.
Additionally, the measurements were taken during an unusually humid outdoor period, which also explains the high moisture values in the battens and counter battens. Generally speaking, moisture damage can be expected in roofs with the above-noted deficiencies. Our assessment is that the roofs have avoided moisture damage thanks to the diffusion-open properties of the underlay, which allow drying outwards."
I can also add that I am talking about a roof without an air gap...
finally, he adds a slightly later study from 07.
http://www.profile.dk/filer/faltrapport_underlagstak.pdf
As mentioned - no one with any experience of diffusion-open underlay roof without an air gap. (preferably with ekofiber and metal as well)
http://www.profile.dk/filer/faltrapport_underlagstak.pdf
As mentioned - no one with any experience of diffusion-open underlay roof without an air gap. (preferably with ekofiber and metal as well)
Beijer has Tyvek to some extent, but I have found a house company that is closing down and has a stock of Tyvek Supro Grid that they are selling at cost price....
If you also want to buy, email me: andreas@motesfabriken.se
If you also want to buy, email me: andreas@motesfabriken.se
However, I need to find a suitable vapor barrier for the inside that matches Tyvek Supron in terms of the 1:5 ratio in vapor resistance... Tyvek has its own so it might be a bit of Beijer anyway.
Master, where are you in the Mälar region? I'm building outside Enköping.
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