Floor Joists Guidlelines

If your home is more than 20 years old your floor joists are most likely solid wood 2x8s 2x10s or 2x12s.

Floor joists guidlelines.

Common sense tells you that large floor joists can carry more load and spacing joists closer together also increases the load bearing capacity of a floor. 9 16 tji joists design properties 6 floor span and load tables 7 8 tips for preventing floor noise 8 allowable holes 9 cantilevers 10 11 roof span and load tables 12 13 framing. The extra two inches of vertical distance when a floor is framed with 2 x 10 joists rather than 2 x 12s can be quite important for example. If your home is more than 20 years old your floor joists are most likely solid wood 2x8s 2x10s or 2x12s.

The notching and boring rules of thumb for solid lumber are shown in fig. Section r502 10 of the international residential code states that header joists can be the same size as the floor joists when the header joist span isn t greater than 4 feet but if the header joist span is more than 4 feet you ll need to double the header joist and ensure that it s capable of. These joists may need reinforcin g to reduce bounciness sagging or excessive deflection in the floor or ceiling. If the cut outs are too large or in the wrong location the joist can be weakened and unable to support the load it was designed for.

Fire safe construction 3 floor performance and tj pro rating 4 5 section 1. Sometimes joists are notched at the end where they bear on a wall or sill. Follow the rules to keep your floor solid. Additional support for the floor joists is achieved by nailing the ends of the joists into headers.

That s the real reason you want to follow the notching and boring guidelines. Trus joist tji joist specifier s guide tj 4000 july 2019.