Nynette Flooring July 15th, 2017 - 19:24:38
In the case of long span truss work, bearing lengths of at least 3" are quite common. Trusses span greater distances than framed floor assemblies and can be designed to span the entire building, eliminating center load bearing supports. They are moderately more expensive than framed floor assemblies, but provide a remarkably strong floor with little deflection or "bounce" to it. Another advantage to this type of structural system, is that utility installations can be run between the webwork components. Never allow trades to cut or drill into the members of a truss, for they are manufactured precisely for the loading conditions they will undergo during the life of the building.
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.
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.
However if you go for a quality engineered wood flooring you can even gone as far as to boil a piece of our floor for 30 minutes and the board still will not de-laminate. The 15mm ply wood under core is what gives the flooring the strength and stability is has. Oak is a natural product and when used for flooring the board widths can change in size. This can cause gaps between boards or the floor to buckle and this movement is most commonly caused by the changing of humidity in the environment. Because of the stability of a quality engineered oak floor it is far less prone to this movement. This stability is also becoming of greater importance today due to the fact that an increasing number of properties are having under floor heating systems installed, which of course causes a frequent change in humidity. Having said this I would again like to reiterate that I am writing in regards to a quality, higher spec engineered oak flooring, and I can not talk for all engineered wood floors.