Installing A Metal Roof Directly To Plywood

Sweep the plywood clean of all dirt and debris with a push broom.

Installing a metal roof directly to plywood.

Do need to rack the house with sheathing on walls or cross bracing. Add the metal panels. Install the roofing screws vertically along each rib in the panel. Epdm roofing installation faq.

I was planning on putting plywood over the rafters and cross the rafters with a 2 x4 every 16 to secure the metal roof to. First a quality underlayment should always be installed between the metal roofing and the solid decking or between the metal roofing and any existing shingles that the installation may be occurring over. On top of this underlayment goes a slip which protects the material from tearing as the metal roof expands and contracts with changing weather. To watch the entire series from the beginning click here.

Installing the metal roofing over 1x4 s allows the ability to also install additional insulation under the metal roof that can t be done the other two ways. But it seems the condensation will affect the 2x4 strapping. Place the first screw. To secure it measure it roll it out over the plywood cut it to the dimensions of the roof with a roofing or utility knife and finally hammer it securely to the plywood with 1 2 inch roofing nails.

In reading online it seems wise to install a vapor barrier over the plywood to prevent condensation from getting adsorbed into the plywood from the steel roof. Be sure the larger edge is laid so that the small edge of the next panel will overlap it. Inspect the plywood for damaged areas. Add purlins on top of this for venting and drainage then add horizontal purlins to mount the metal roof to.

When using plywood nail it directly to the purlins and screw the metal roofing panels through the plywood into the purlins as instructed by the manufacturer. Remove all unused vents pipes and protrusions. In this installation the vapor barrier is installed on the side of the insulation nearest the interior of the building. Take care the first piece is aligned precisely perpendicular square to the edge.

If a proper roof inspection isn t done the 1x4 s could be installed over rotten plywood which means the screws could pull out. Take your first sheet of metal and place it on the roof so that it overhangs the edge at least 3 4 in 1 9 cm. Always begin working at the point with the longest peak to eave distance. How to apply metal roofing over plywood step 1.