Keeping Bugs Out Of Corrugated Metal Roof Attic With Purlins

Just trying to put the finishing touches on the plans for a very small 12x16 cabin and am unsure about the best way to install the metal roof.

Keeping bugs out of corrugated metal roof attic with purlins.

The whole point of the roofing felt is to handle the condensation the best way to fix the problem is to remove the roofing panels install plywood roof sheathing and then re attach the roofing panels. Traditionally we ve insulated the roof panel to try and keep the temperature on the panel from reaching the dew point. There seems to be two methods 1 purlins or 2 decking with felt. The better option is to install 1x4 purlins creating a 3 4 thick air space.

I am heavily leaning towards 2x4 purlins because the pitch is 12 12 and it will give me a ladder to walk on for ease of installation. Make sure that the insulation you are using is the same thickness so that the metal roof will fit better. 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 barn shop or other outbuilding you can attach your metal roof directly to the purlins.

And then you put down horizontal battens for the roof panel attachment. But that is a lot of work. Another possibility is to install closed cell spray foam on the underside of your metal. This provides a path to exit for any leaks thru the metal roof but provides little ventilation beneath the metal roofing.

We ll add a vapor barrier so the moist air does not flow up through the insulation and condense on the roof. Lay the first purlin at the ridge of the roof down to the chalk line beginning at either corner. The resulting vertically oriented chambers can then be ventilated by bringing fresh air in at the boom and exhausting it out at the top. Snap a chalk line horizontally across the roof two feet down from the top.

Ontario ca 91762 909 467 2016. This has very positive results as far as keeping heat out of the attic. One of the more popular methods of placing metal roofing on a home is to lay down purlins across the existing shingles. The problem with using.

Fasten the purlin with 16d common nails into each vertical rafter. In this case simply lay the insulation between the purlins. Insert two equally spaced nails into the rafter. But a preinstalled membrane may be even more effective at removing condensation.

In a residential application however condensation is a concern.