We explain how hollow or suspended floors are made and what the key building regulations that affect them are.
Floor joist timber floor construction methods.
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.
The following table gives details of allowable spans and spacing between joists for the most common timber sizes used in floor construction.
Building and understanding a suspended or hollow timber floor.
The latter options are more expensive but provide considerable benefits.
Purchase the type of lumber that matches the width of the existing joist.
Measure the width and length of the existing joist.
69 chapter 4 floor construction woodframe floor systems and concrete slab on grade floors are discussed in this chapter.
Most new construction uses 2 by 8 lumber for joists although 2 by 6.
Solutions for first floors include traditional softwood joists timber i joists or open metal web joists.
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.
Although cold formed steel framing for floor systems also is permitted by the irc it is not covered here.
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.