Osb Over Existing Sheet Metal Roof

Avoid putting osb on wet roof trusses.

Osb over existing sheet metal roof.

Today a shiplap roof is usually 60 years old. In the case above the shear forces in the last 12 foot bay at each end of the roof have had osb placed between the roof purlins and the steel roofing. 3 install 1x4 purlins down over the shingles before installing the metal roof the third way to install a metal roof over shingles is by applying 1x4 purlins over the shingle roof. Avoid butting osb panels tightly.

This is by far the most common way to install a metal roof. Metal roofing roofing answers roofing installation roofing materials oriented strand board commonly referred to as osb is a type of engineered lumber similar to particle board formed by adding adhesives and then compressing layers of wood strands. Let s take a look at the most common types of metal roofs for houses. After the 1960s the predominant residential roofing substrate became 1 2 cdx plywood.

Whether you are looking to install a metal roof on a shed or a house it s important to know the difference in the various types of metal roofs available. Why re sheet over shiplap. As long as the plywood under the shingle roof is in good condition this way can provide many benefits. Table 2304 7 3 gives the 7 16.

When the steel roofing can t carry the load other shear carrying materials such as 7 16 osb may be added to the assembly. Osb comes in 4 by 8 foot sheets as does plywood but the manufacturing process allows the production of longer and wider ones. Is osb acceptable as roof decking for metal roofing. Leave a 3 mm 1 8 inch gap between the osb panels to allow for expansion.

Stagger the panels over the roof with 2 supports between. Over time shiplap fir wood resin dissipates causing the boards to shrink crack form knot holes and become extremely brittle. Open spaces form between the once tightly fitted. An affordable option and easier to lay than shingles tin is the most commonly used type of metal roofing.

From the 2012 ibc international building code table 2304 6 1 over framing spaced 24 inches on center 7 16 osb fastened with 8d common nails six inches on center at the edges and in the field will support a maximum design wind speed vult of 110 mph miles per hour in exposure b or 90 mph in exposure c.