Roof Boards Spacing

So the space between rafters can be greater without reducing the maximum span.

Roof boards spacing.

Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run. For example in the rafter span table below the highlighted cell in the 40 live load table indicates that 2 x 8 southern yellow pine joists that have a grade of 2 that are spaced 24 apart can have a maximum span of 10 feet 3 inches 10 3 if designing for a live load of 40 lbs ft 2. If the wood structural panels are tightly butted there is no room for expansion and buckling can occur. Apa recommends a 1 8 inch space between panel edge and end joints.

The last board won t look good if it s skinny or cut at an angle. Deck boards should be spaced well apart 1 8 is the minimum and i would go wider usually 3 8. Adjust the spacing between deck boards gradually over the next 10 rows of decking until the distance to the house is equal. How many nails per board in roof sheathing.

Plywood and oriented strand board osb like all wood products will expand or shrink slightly with changes in moisture content. Without that gap you get stuff accumulating between the boards that you can t easily clean out. The type of nails you ll need to use during the sheathing process depends on the roof material thickness. This is a centerline measurement from the center of the board so about three quarters of an inch from the side of the board on its narrowest face.

You want to use 12 inch spacing on smaller pergolas where the weight of many rafters close together won t cause the beam to sag or on pergolas 14 feet in width and under. When to use 12 inch spacing. There are typically 12 16 or. Roof sheathing basics the skeleton of a roof is formed with rafters or trusses generally spaced 16 inches or 24 inches apart from the center of one rafter to the center of the next.

The same concept holds true for roof trusses. Julia i don t know if code applies but in my opinion your deck problems are the result of an inexperienced carpenter. To stabilize the rafters support the roofing material and hold the entire roof together roof sheathing is installed. Adjust spacing between deck boards measure to the house at both ends and in the center when you get within about 5 ft.