Do I Need To Cross My Floor Joists

The added depth of these two allows extra support and reduces bouncing.

Do i need to cross my floor joists.

A sister joist is a second joist that goes alongside the first one and stiffens the floor. For two of the three fixes we show solutions a and b you need access to the floor joists from below. Joists that have severe crowns need to be set aside or some of the crown needs to be trimmed off so the floor remains fairly flat once covered with plywood or oriented strand board. But larger is not always better when builders are constructing a home or adding a room addition.

Joists you may have thought adequate for your attic floor may not come close to being strong enough. This type of. Walking on joists before all accessories and floor decking are installed i joists are unstable and can roll over if walked on leading to injuries. Floor joist bridging is critical to the structural strength of a floor as shown in figure 1.

How joists support floors and ceilings joists the horizontal members that span two walls and or beams have to carry the weight of the walls people furniture appliances and other stuff we place on them. For more serious weaknesses you may need to shore up the floor joist structure with a cross beam and lally posts. Things you will need. You don t need any special skills or tools to stiffen your floors and all the materials are readily available at home centers.

If you purchase engineered floor joists that resemble steel i beams these have no crown in them. Proper bridging distributes the load on the floor to other joists and over time prevents floors from sagging and squeaking do to floor joists twisting and warping. 2 by 6 or 2 by 8 lumber. Yet it is not uncommon to find bridging not properly installed or missing all together.

The fixes we ll show work for both solid wood joists and wood i joists. 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. Don t allow your crew to walk on i joists or install subfloor sheathing until all hangers blocking panels and temporary safety bracing strapping are fully installed. When a load is applied to a joist the wood fibers along the bottom edge go into tension and those along the top go into compression fig.

The only caveat to this is that you need to make sure you have enough space to add another joist. 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. Working your way across the floor add the braces between adjacent joists one at a time at eight foot intervals. But there is a catch.