Nynette Flooring August 07th, 2017 - 17:49:33
Truss floors are simply that. They are constructed from small dimensioned lumber, interconnected in a webwork pattern by the use of metal or wood plates. Occasionally, the trusses will be built on site, utilizing plywood plates to connect the webwork together. Generally they are installed 24" apart, either suspended on bearing walls or beams, or installed with plywood trim or rim joists around the perimeter. Strapping is installed on the bottom side, to prevent turning in place, which is a common ailment for deep truss components.
All joists must extend at least 1-1/2" on to a bearing assembly, of either a beam or full height wall, unless metal hangers are installed to provide proper bearing support against other structural components. Beams, which support the floor joists over greater spans, are constructed in the form of laminated joists often referred to as built up beams, or one piece solid load bearing beams, cut from logs or manufactured. Electricians and plumber may often cut or drill into the joist work to install utilities, and this is accepted, so long as they do not remove more material than what is required by codes. This type of floor system is usually the cheapest to install.
Raw sheathing comes in 4`x8` sheets, most often installed as 3/4" thick plywood panels. This type of sheathing is adequate for spanning joist work spaced up to 24" apart. The sheathing is lain with the joints staggered in such a matter, that no two edge joints line up with adjoining sheets. It is very easy to install, requiring the least amount of labour. The sheets are fastened with either 1-1/2" flooring screws, or 2-1/2" nails, spaced about 8" apart. Although not required, it is a good idea to provide backers or supports under the joints, between sheets which run perpendicular to the framed floor assembly.
With reclaimed material waste factor is a huge variable. How much effort does the manufacturer take to give you a 100% usable product? Poorly milled with very little defecting and culling done on a solid wood floor that costs $6/sf and has a 15% waste factor actually costs more than a similar product that is milled better costing $7/sf with a 2% waste factor. That extra wastes costs more in shipping and labor to defect. This is one of the hardest things to demonstrate to a customer that the face value costs doesn`t necessarily represent the actual raw material cost unless one is truly comparing identical quality and specified products.