In a barn shop or other outbuilding you can attach your metal roof directly to the purlins.
Pole barn metal roof underlayment.
Once again this is used on cold roof construction.
Synthetic underlayment is a newer innovation that is taking over the metal roofing industry as a better more advanced replacement for felt underlayment.
Insulation and ventilation are going to be keys for you.
Metal roof condensation.
Single bubble vapor barrier is designed to prevent such inside rain by keeping the metal from sweating.
Pole barn vapor barrier.
The underlayment doesn t really impact condensation in your case the condensation will just occur on it rather than on the metal itself.
It serves as a moisture barrier as well as a slip sheet.
But a preinstalled membrane may be even more effective at removing condensation.
In my case i planned to use osb on the sides and roof asphalt shingles up top and vinyl siding on the sides.
This type of underlayment is critical to a quality roof installation.
Metal roofs are notorious for the annoying drips that occur inside the building.
Your risk is when warm moist air from inside hits the cool back side of the roof system.
Moisture can collect on the inside of your metal roof whenever warm moist air inside your building meets the cold metal of your roof.
In a residential application however condensation is a concern.
When hot roof construction is done a roof with no ventilation a breathable underlayment is recommended.
The problem with using.
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.
Synthetic underlayment is a roofing accessory created by weaving spinning together polypropylene or polyethylene and a polymer to form an all over protective barrier to put between the roofing material and the roof deck.
We ll add a vapor barrier so the moist air does not flow up through the insulation and condense on the roof.
I m building a pole barn but don t wish any moisture underlayment for corrugated metal 4 18 2005 within the corrugated roof discussion of the residential metal roofing forum.
It will want to condense.
Fire retardant poly barrier double bubble reflective insulation is a durable layer of polyethylene bubbles bonded to and.
Traditionally we ve insulated the roof panel to try and keep the temperature on the panel from reaching the dew point.
I m looking at a pole barn with steel trusses made of 2 2.
R value up 6 8 down 15 2 horizontal 8 5.
