Ground Floor Joist Sizes

Floor joists are typically 2 by 8s 2 by 10s or 2 by 12s.

Ground floor joist sizes.

In general practice 2x8s 2x10s or 2x12s are used when framing a raised floor instead. Though joists may be any size that you desire using typical floor joist and beam specifications ensures that you can find hardware to fit the joists and that the floor provides adequate support for furniture and other items in a room. In the past 2x4s or 2x6s were sometimes used as floor joists. Joist span and spacing is set by your local building code.

This size is no longer acceptable when framing a structure. I asked my local building official how he checks a deck plan to make sure the joist size and spacing combination will meet requirements of the building code he goes to the 40 lb. All the figures are based on normal domestic floor loadings where the floor construction is typically 18 25mm floor boards sheets with up to 12 5mm thick plasterboard and skim underneath. While most residential construction uses 2x8 joists with 16 inch spacing there are many other factors you need to consider when determining the proper joist span length.

For conventional guardrail post installation bolted to the side of the framing larger framing will provide more strength in the rails. Live load floor joist span tables in chapter 7 of the state residential code based on the 2012 international residential code. When building a house or even a deck it is important to confirm you have the correct joist sizes spans and spacing before you get started. True floor joist span calculations can only be made by a structural engineer or contractor.

Some newer homes have manufactured i beam shaped joists. 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. For upper level decks 2x10 is recommended as the minimum size to use for strong guard post connections. Choosing the correct floor joist size depends on your building application joist spacing and several other factors these include the length of the span as well as the type and grade of the lumber being used.

Ceiling joists are usually 2 by 6s or sometimes 2 by 4s if it is an older home. 2x6 joists should only be used on ground level decks that do not require and will not provide for any guards. The weight of the timber floor itself consists of the timber joists the plasterboard ceiling underneath it except for suspended timber ground floors the floorboards and the nails or screws used to fix both of the aforementioned coverings. A floor s framework is made up mostly of wooden joists that run parallel to one another at regular intervals.

Floor joists or beams provide the below surface support for the wood subfloor of a room.