We ll add a vapor barrier so the moist air does not flow up through the insulation and condense on the roof.
Pole barn metal roof underlayment.
The underlayment doesn t really impact condensation in your case the condensation will just occur on it rather than on the metal itself.
The problem with using.
This type of underlayment is critical to a quality roof installation.
Metal roof condensation.
I m looking at a pole barn with steel trusses made of 2 2.
Traditionally we ve insulated the roof panel to try and keep the temperature on the panel from reaching the dew point.
But a preinstalled membrane may be even more effective at removing condensation.
It will want to condense.
This building will have a shed roof that will be difficult to ventilate well so it seems that the breath ability of felt paper would be good and would be more likely to be installed properly by a pole barn contractor but i have heard that the felt is a poor choice for metal roofs because of the heat and expansion of the metal.
Make sure the product is designed to be used under metal.
Pole barn vapor barrier.
Metal roofs are notorious for the annoying drips that occur inside the building.
Underlayment and insulation.
Your risk is when warm moist air from inside hits the cool back side of the roof system.
Fire retardant poly barrier double bubble reflective insulation is a durable layer of polyethylene bubbles bonded to and.
R value up 6 8 down 15 2 horizontal 8 5.
Single bubble vapor barrier is designed to prevent such inside rain by keeping the metal from sweating.
When hot roof construction is done a roof with no ventilation a breathable underlayment is recommended.
It serves as a moisture barrier as well as a slip sheet.
I live in an hoa and we don t allow steel buildings roofs.
In a residential application however condensation is a concern.
In a barn shop or other outbuilding you can attach your metal roof directly to the purlins.
Once again this is used on cold roof construction.
In my case i planned to use osb on the sides and roof asphalt shingles up top and vinyl siding on the sides.
Insulation and ventilation are going to be keys for you.
Moisture can collect on the inside of your metal roof whenever warm moist air inside your building meets the cold metal of your roof.
