Nynette Flooring August 11th, 2017 - 17:36:58
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.
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.
I encourage you being cautious about potential discoloring of the wood floor in direct proportion to the shape of the center rug piece over time. Discoloration will occur not as a result of the throw rug or center rug piece but as a result of sunlight beaming on the wooden floor in areas around the center rug piece. You see, underneath the center rug piece sunlight cannot get to the wood. So, the color of your wooden floor beneath the center rug piece would be lighter in color over time than the exposed areas. I recommend you use throw/scatter rugs instead of center piece or area rugs as these would be more readily removed, freshened or relocated to minimize a lengthy tenure in one location.
One drawback is that this type of floor requires special hanger systems designed for the joists, to enable them to be hung from each other or against beams/bearing walls. Manufactured joists are becoming a popular flooring system, for they are relatively cheap, reduce labour time and provide adequate support. However, builders need to familiarize themselves with its installations, for poor installation can cause severe structural damage to the joists. A good example is a three point, center bearing joist, left with the top chord uncut, which can potentially fail or pull apart, over the center bearing point.