I've read through several of the questions and replies about roof condensation issues, especially as associated with metal roofing. I am building a house (
Thank you, Todd.
My plan as it stands after more reading and professional advice is to build the rafter system for 10 inches of dense-pack cellulose insulation above the cathedral ceiling. I will sheet the roof on top of this rafter structure, then I will run 1x2 vertical strapping above on top of a moisture barrier on the sheeting and then 1x4 horizontal strapping (purlins) on 2' centers above that for the metal. This will provide ventilation for any condensation with vents at the soffits and ridge.
Darryl
Guest User
2007-10-29 08:26:14.000000
Most manufacturers of most metal roofing products recommend installation over decking and underlayment rather than over battens for residential applications.
Always make sure that your installation methods are in keeping with the manufacturer's instructions and specifications. That is critical.
Having a good vapor barrier and avoiding excessive moisture in the house is very helpful at avoiding condensation issues. However, ventilation is still safest.
You could vent above or below the sheathing.
Todd Miller
2007-10-27 19:55:19.000000
That is a solid plan. Make sure that the metal product you select is suitable for installation in this manner.