Insert a nail every six inches along the perimeter of the felt and every foot on the inside to secure it to the plywood.
How to make a metal roof stop sweating.
Air circulation and ventilation stagnant indoor air is the perfect environment for condensation to occur.
The lower the pitch of a metal shed roof and also the deeper the corrugations the worse the problem of metal roof sweating.
Metal panels that have dripstop or rfoil are well equipped to handle the rigors of the elements.
This will provide flow through ventilation at the point where the hottest air rises to.
Having vents in all elevations of the shed is an effective way of minimising metal roof sweating.
You must have a vent at both ends not just one.
The roll of felt is spread out over the entire roof on top of the plywood and nailed down with roofing nails.
The use of ceiling and floor fans improve conditions for evaporation to occur.
If there is no high level ventilation already installed install a 15cm ventilation grille at the highest point at each end of the eaves.
The key to getting condensation to evaporate is air flow.