Floor Joist Timber Floor Construction Methods

69 chapter 4 floor construction woodframe floor systems and concrete slab on grade floors are discussed in this chapter.

Floor joist timber floor construction methods.

Rather the reader is referred to the aisi standard for cold formed steel framing prescriptive method for one and two family dwellings aisi 2001 for guidance. 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. Unlike softwood joists timber i joists do not warp over time providing a quiet floor while open metal web joists can provide an easy means of installing services. Whether building a ground floor suspended timber floor or a first floor hollow floor we explain the different options and techniques that you can use in its construction.

We explain how hollow or suspended floors are made and what the key building regulations that affect them are. The latter options are more expensive but provide considerable benefits. The following table gives details of allowable spans and spacing between joists for the most common timber sizes used in floor construction. Although cold formed steel framing for floor systems also is permitted by the irc it is not covered here.

On top of that the natural drying process of the intermediate floor once heating has been applied might reduce moisture content from anywhere between 12 14 at the time of construction down to 8 10 when fully dried. Most new construction uses 2 by 8 lumber for joists although 2 by 6. Building and understanding a suspended or hollow timber floor. Solutions for first floors include traditional softwood joists timber i joists or open metal web joists.