Nanine Flooring July 31st, 2017 - 18:02:25
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.
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.
Most commonly installed are interlocking sheathing panels. This type of sheathing is generally 5/8" thick, and manufactured as either plywood or aspenite (commonly referred to as "chipboard") in 4` x 8` sheets. The sheets come with the long edges designed to interlock with a tongue on one edge, and a grove on the opposing edge. They are installed by simply pushing or pounding the sheets together, and nailing or screwing them to the joist work, in the same manner as raw sheathing. It is often the cheapest to install.
If your price-point is not even in the same zip code, maybe it is in a different state, start shopping other options. For example if you are in the $1-2/sf range look at the deep discounters or laminate options. The FSC certified 12mm exterior birch plywood that we use to manufacturer the engineered flooring costs us that much alone, not counting all the other labor and materials.