Floor Trusses

Open web trusses are the ideal match with a sprinkler system, maximizing use of space and making installation easy.

This research report will focus on manufacturer or trade association deflection requirements for a number of floor topping/covering related products where deflection requirements may impact serviceability.

Lumber Design Values

No matter the species, component manufacturers (CMs) purchase and rely on the accuracy and reliability of many different lumber design properties, including: bending (Fb); shear parallel to grain (Fv), compression perpendicular to grain (Fc^), compression parallel to grain (Fc), tension parallel to grain (Ft), and modulus of elasticity (E and Emin).

What is the industry standard for ordering residential roof truss systems: Should the general contractor/builder field measure before ordering trusses or should he rely on the blueprint? Who is responsible for their accuracy – the plan service, the truss manufacturer, the builder/general contractor or the framing contractor?

I am researching building products for a new home and I wanted to use metal plate connected floor trusses. When I took my plans to the builder, they cautioned me against using these floor trusses. They stated that they were not engineered products, they do not carry any kind of warranty, and they do not know how long they last over time. My basement span is 30 ft., they said trusses could not span 30 ft. I really would like to use floor trusses, but now I am unsure. Could you offer any information?

Do you have any information on the use of in-floor radiant heat with 4x2 open-web floor trusses? Are there any adverse effects to the lumber as a result of moisture build up?

We recently received bids on a school project, which referenced UL P523. This assembly used light-gauge steel trusses. We noted on the drawing that we could accept an alternate design using wood trusses in lieu of light-gauge steel framing, if the alternate design could meet the fire ratings.

I am looking for some information regarding black surface mold on lumber. Does it alter the integrity of the lumber stress values? I have a client who wants to use “all dry” lumber for his construction but I do not know if this is really necessary.

We are having a house built and on a recent visit we brought along a friend who builds houses for a living. He noticed that the trusses were wet and a bit moldy. The wood seemed warped, brown, and had white splotches on it. We are worried that it would later make the roof uneven. How could we tell how long the trusses have been exposed to the elements? What options do we have from here? Do we request new trusses, or can these be repaired?

I am a building designer on a salt storage building project. I would like to use metal plate connected wood trusses in the design. What should I specify for the metal connector plates?