Floor Joist Timber Floor Construction Methods

Building and understanding a suspended or hollow timber floor.

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. Solutions for first floors include traditional softwood joists timber i joists or open metal web joists. The method and type of fixings used to secure the floor deck to the top of the joists also needs to be considered. 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.

Purchase the type of lumber that matches the width of the existing joist. Most new construction uses 2 by 8 lumber for joists although 2 by 6. Measure the width and length of the existing joist. The following table gives details of allowable spans and spacing between joists for the most common timber sizes used in floor construction.

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. 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. The latter options are more expensive but provide considerable benefits. 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.