Metal Roofing Directly Over Plywood

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.

Metal roofing directly over plywood.

Also there are numerous better underlayment products as mentioned above including grace products and a host of others all better than felt. Video of the day. The metal will be attached to at least 3 4 purlin and 1 2 plywood instead of just 1 2 plywood which should make the overall roofing system stronger. See the image below.

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. Align the first metal roofing panel so that it overlaps the edging by 1 2 to 3 4 of an inch and is square to the roof line. This product is generally used in hot roof low slope applications with aluminum roofing. Complete and separate roofing systems such as standing seam metal roof systems that are designed to transmit the roof loads directly the buildings structural systems and that do not rely on existing roofs and roof coverings for support shall not require the removal of existing roof coverings.

See the image below. But probably the best benefit that comes from using purlins is the air gap it creates between the metal roof and the existing shingle roof. Yes metal roofs are placed directly to the plywood over icynene insulated roof sheathing thats how i always had it done and warranteed. Energy efficient and available in a variety of colors that will add value to your home metal roofing is a wise choice for homeowners.

To learn more about installing the correct underlayments for your metal roof project or to get a quote feel free to contact us here. The plywood should be clean and free of raised nail heads to provide a uniform deck structure for the metal. 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. Be sure the larger edge is laid so that the small edge of the next panel will overlap it.

I have removed all the old shingles from the roof boards not plywood the roof is in great shape and have installed an ice shield over the roof. Install the roofing screws vertically along each rib in the panel. In this installation the vapor barrier is installed on the side of the insulation nearest the interior of the building.