Can I use I-joist for roof?

Can I use I-joist for roof?

Some builders use manufactured I-joists not only to support floors, ceilings, and flat roofs, but also in place of either sawn-lumber rafters or wood trusses to support pitched roofs.

How far can wood I-joist span?

With these factors, the lightest joist will have a maximum span of 17 feet, 8 inches. This is the most common as the typical span is 15 feet. The heaviest joist, along with the above factors, will span a maximum of 23 feet, 8 inches.

Are I joists stronger than timber?

Are I joists stronger than timber? I joists are specifically designed to offer strength in areas that dimensional lumber is incapable of. They can span greater distances, and are considered to be 50% stiffer than dimensional timber under traditional frame spacing.

What size joists do I need for a flat roof?

The joists should be sized using either the TRADA span tables or BS EN 1995. The sizing and spacing will depend upon the loads imposed on them and the required span. Wherever possible, joists should span the shortest distance. Common joists sizes are 200 x 50mm, 175 x 50mm, and 150 x 50mm.

What size lumber are roof rafters?

You can use either 2×6 or 2×4 rafters for roofs with a 3/12 pitch or greater, but it depends on the overall size of your shed. For roofs that won’t experience heavy snow loads, a gable roof can span up to 22′ with 2×4 rafters.

Do I joists need blocking?

Blocking panels are required at each end of floor joists not otherwise restrained from overturning by a band joist or rim board. Blocking panels are required between floor joists supporting load-bearing walls running perpendicular to the joists.

How much weight can an I-joist hold?

That means the joists can support a minimum of 40 pounds per square foot live load. Though, by consulting the 50 pounds per square foot live load/10 pounds per square foot dead load table, you can see the joists’ span would need to be reduced to 11 feet 11 inches to support heavier weight safely.

Are I-joists any good?

I-joists can be a great product for a new home project. Your carpenters will like them because they are lighter…which makes it possible for one person to install. And similar to the floor truss, I-joists can span greater distances than 2×12’s.

What timber should I use for flat roof?

In the majority of cases the covering will be plywood or OSB timber which is more commonly called Stirling board. When timbers are used in flat roofing they obviously need to be waterproofed so boards are normally laid across the joists and then a felt or rubber is used to cover the boards to make them waterproof.

What size joist do I need for roof?

Max. Live Load 20 lbs/ft2 (956 N/m2)

Maximum Span (ft – in)
Nominal Size (inches) Rafter Spacing, Center to Center, OC (inches) Lumber Grade
2 x 6 16 14′ – 11”
24 13′
2 x 8 12 21′ – 7”

How do I block an I-joist?

To make the blocks, I cut sections of I-joist 1½ inches smaller than the space between the joists, then nail a scrap of ¾-inch subfloor material to each end of the block [1]. This creates two large nailing fins. Calvin Cutts works from a ladder to install the blocks.