Replies

1. GBA Editor
   Martin Holladay | Jul 18, 2017 04:23am | #1

   Jonas,
   First of all, I don't think the fact that the most common roofing in Paraguay is metal roofing is a "problem." Metal roofing is a great option, and there is nothing wrong with metal roofing installed over an unconditioned attic.

   You're right that the type of insulated metal panel than you linked to is rarely used for roofing in North America. If you choose to use it -- I imagine that it is an expensive option -- it means that you are creating a conditioned attic. I think that the trickiest part of the job (assuming you want to create a conditioned attic with these insulated panels) is creating an air barrier. The metal panels are corrugated, so it will be important to seal air leaks at the perimeter of your attic, and at the ridge. I'm not sure how you would do that, especially at the ridge, without spray polyurethane foam.

2. 
   user-6885983 | Jul 18, 2017 08:02am | #2

   Hello Martin,
   thanks for the quick response!

   I think I expressed myself wrongly, most common roofing options here are:
   - Traditional straw
   - Brick tiles
   - Tin roofs
   Normal construction method is a cathedral ceiling without any insulation.
   Humidity and Mold generated from bad foundation insulation and leaking roofs is 100% common and generally accepted as you live outdoors 75% of the year ;-)

   Asphalt shingles arent common could be imported from Brasil but are not my preferred option.

   Metal roofs I have found until now are through fastened and real thin material.

   The insulated metal panels can also be bought with a straight surface below, which for me seems to be the most positive thing about them, solving part of the ridge Problem.

   My point of view right now:
   - If I find a good quality "simple" straight metal roof (similiar to standing seam), creating a vented attic, where the air in and outlets a protected by mosquito nets, might be a good solution.
   - If I cant find a good quality "simple" straight metal roof, I would go with the insulated panels with straight surface and try to create an air sealed attic.

   Appreciate any comments,

   thanks ,

   Jonas

3. GBA Editor
   Martin Holladay | Jul 18, 2017 08:33am | #3

   Jonas,
   In a hot, humid climate, you don't want to vent an unconditioned attic. Just skip the vents.

   For more information, see All About Attic Venting.