Floor Joist And Wall Framing

The exact number of floor joists you ll need will depend on the size of the floor.

Floor joist and wall framing.

The exterior walls of a house are usually the main load bearing walls but some interior walls may also bear loads. If the joists run perpendicular to the wall an adjustment should not be necessary. As a general rule floor joists should be spaced 16 inches 41 cm apart for maximum stability. 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.

Normal spacing is 16 inches on center from center to center though some floors may have joists on 12 inch or 24 inch centers. Double plating is most common on load bearing walls unless the roof rafters or trusses and floor joists stack directly over the studs in the wall then a single top plate can be used. If the joists are parallel to the new wall adjust the layout so that the wall is directly under a joist. This article teaches you how to build a floor for a house on a concrete foundation.

Tilt the wall on its bottom plate and lift the wall upright. True floor joist span calculations can only be made by a structural engineer or contractor. This framing system can also be used for framing storage shed floors this floor framing system is typical over basements and crawl spaces. 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.

This sample table gives minimum floor joist sizes for joists spaced at 16 inches and 24 inches on center o c for 2 grade lumber with 10 pounds per square foot of dead load and 40 pounds of live load which is typical of normal residential construction. Floor joists spaced on regular intervals span the areas between supports such as walls foundations girders and beams. Joists are spaced at regular intervals much like the studs in a wall frame. Large openings in the wall are made for windows and doors.

Joist spans and spacing are determined by engineering that is published by the manufacturer. Framing a floor using i joists. The top plate can be either single or double. They are covered with subflooring panels of plywood or oriented strandboard osb to complete the floor s structural assembly and create the solid continuous platform on which you install tile carpet or other finish flooring.

Draw and label your framing plan to scale and double check each of your measurements to make sure they suit the structure s size and support requirements. Joist spans sections r502 3 1 1 and r502 3 1 2 of the international residential code include tables that list acceptable spans for floor joists.