Typical Floor Joist Size Uk
The floor joist span tables are based on the loadings given in the amended version of bs 6399 1 which is an imposed load of either a uniformly distributed load of 1 5 kn m or a concentrated load of 1 4 kn.
Typical floor joist size uk. Floor joists or beams provide the below surface support for the wood subfloor of a room. Common joist spacings are 12 inches 304 8 mm 16 inches 406 4 mm and 24 inches 609 6 mm. These tables can help calculate whether floor joists are strong enough to support themselves and the load they carry without the help of any walls underneath. Looking at this table you will see there is a choice in the size of floor joist 2 x 6 2 x 8 2 x 10 or 2 x 12 and there is a choice in the joist spacing 12 16 or 14.
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. This is simply the depth of joist required. The following table gives details of allowable spans and spacing between joists for the most common timber sizes used in floor construction. 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.
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. Usually refers to sawn carcassing that is ordinarily used for building and construction ie joists beams etc. 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.
Traditionally this material was sold in sawn sizes such as 4 x 2 or 47mm x 100mm now days the uk market is used to offering this material regularised ie it has smooth planed eased edges making it easier to work with and. 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. The table excerpt above is simply a sample and may not be valid for your region. Joist span and spacing is set by your local building code.
Surveyors and structural engineers use data from tables below to help calculate the size of timbers necessary to give adequate support to timber floors. A deeper joist can be beneficial when the engineered i joist is. All joists are bridged sample floor joist span table. The size of the i joist is affected by the length of the span and longer spans require thicker deeper i joists whereas smaller spans can use i joists that are thinner.
Joists are to have minimum end bearing of 40mm. The exact size necessary may be stipulated by the building code required for a particular structure.