Lateral Support For Floor Joists

Section r502 7 of the 2009 international residential code specifies that joists must be laterally supported by solid blocking that s not less than 2 inches thick and the full depth of.

Lateral support for floor joists. Where the subfloor support is provided by a foundation wall that is acting as a subfloor brace blocking must be continuous for a minimum of 1 8 m. For one it is designed to prevent floor joists from rolling over from lateral loads or shear such as in high winds or storms. 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. This beam supports the floor joists of the house s ground floor.

Note that the diagonal brace and l bracket details connect to poured concrete foundations which are common in my area. This article provides step by step instructions and pictures on how to make structural repairs by sistering floor joists alongside weak joists. But larger is not always better when builders are constructing a home or adding a room addition. 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.

As a bonus this l bracket provides vertical support in addition to lateral strength. For example in storm or high wind conditions rim board will help distribute horizontal loads more evenly to resist shear and transmit shear loads to the sill plate or along the axis of the joists. For ground floor joists along all lines of horizontal support bearers. Secondly it can also be used to transfer load from the wall above to the floor continue reading.

Materials for this anchor cost about 41 including the 20 bracket and the second joist. Lateral restraint straps at floor or roof level must not be retro fitted by plug and screwing the strap to the masonry. Locations where lateral support is required. Installation usually takes less than 30 minutes.

If you have sagging cracked or twisted joists which can happen in older houses this project will provide the extra support the floor needs. I m installing the first floor joists. I ll need to strap them to the parallel walls as per my regs below. Connecting the rim board to the joists provides lateral support to the joists and resistance against rotation.

The most common example can be seen in a basement or crawlspace where a large main beam runs down the center of the space and is supported every 8 feet or so with a column or concrete pier. Joists also may get support from beams located at or near the middle of the joist span. Use blocking in the gap between the joist rafter and the parallel wall at all lateral restraint strap positions as well as in between joist rafters for the length of strap required. Blocking when applied to an engineered floor system provides lateral support between floor joists and can serve different purposes.