How far apart are floor joists in a house?
Normally, floor joists are spaced 16 inches apart on center. This means from the center of one upright joist to the center of the next. Given that 2x8s are actually 1-¾ inches wide, it works out to be 14-¼ inches between each joist. With some structures, floor joists are required to be 12 or 24 inches apart on center.
In general terms, joists spaced 16 inches on center can span 1.5 times in feet their depth in inches. A 2x8 up to 12 feet; 2x10 to 15 feet and 2x12 to 18 feet. The larger the deck, the larger the joists.
- Ceiling joists are usually installed either 16 or 24 inches on center, which means roughly 16 or 24 inches apart. Once you've located the first one, the others are easier to find.
- Sistering joists means beefing them up with additional material. Doing so strengthens weak joists and can help straighten sagging joists. Framing lumber is the typical choice for sistering material, but engineered lumber products actually add more stiffness than dimensional lumber.
- Starting with your perimeter, mark the location of each deck post to locate the fitting position. In general, posts should be spaced no more than 8 feet apart. Some builders position them every 4 feet for a completely rigid frame. The maximum distance between footings is determined by the size of your joist material.
Max. Live Load 30 lbs/ft2 (1436 N/m2)
|Maximum Span (ft - in)|
|Nominal Size (inches)||Joist Spacing Center to Center (inches)||Lumber Grade|
|2 x 8||12||15' - 10"|
|16||14' - 5"|
|24||12' - 4"|
- The band joist and sill plate are the set of boards (in wood frame houses), or blocks (in a brick house) that sit on top of the foundation wall and run in a band around the house.
- The following terms define all of the important components of a typical deck.
- Beams or girders: Hefty framing members (usually 4x, 6x, or doubled or tripled 2x stock) attached horizontally to the posts to support the joists.
- Bridging: Short pieces of lumber between joists that strengthen the framing.
- Typical costs for vinyl or wood fascia boards and soffits range from $6 to $10 per linear foot, and the cost to fit out a simple single-level home is anything from $600 to $2,000. The price of aluminum fascia ranges from $8 to $20 or more, and the budget for a single-story home ranges from $800 to $6,000.
When supporting joists that span 12 feet with no overhang beyond the beam, a double ply beam can span in feet a value equal to its depth in inches. A double 2x12 beam can span 12 feet; a (2) 2x10 can span 10 feet and so on.
- The header spans an opening for a window or door, or a cut-out in the roof or floor for a skylight, chimney, or staircase. Typically at least twice the size of surrounding framing members, a header is often built up from two studs, joists, or rafters.
- Mark all the plates at once
- Measure the distance between the king studs (door width plus 5 in.).
- TIP: Mark and measure at the same time.
- Mark the cripple locations.
- Keep edges flush.
- Transfer the layout marks to the header.
- First, fasten the header to the king stud.
- Add the cripples before the double top plate.
- Typically a pre-hung door is measured in 30 inch and 36 inch sizes with additional sizes available in non-standard widths. The doors are also a standard 80 inches tall. Presuming the door is a 36 inch wide door, the dimensions of your opening should be 37 1/2 inch wide by 81 1/2 inch tall.
Updated: 6th October 2019