Moisture Control

Moisture Content Equilibrium And Truss Movement

Question: 

How long does it take the moisture content to stabilize in a wood truss? I live in southern California. Also, how much deflection should be expected in a scissors truss over a partition wall?

Trusses Exposed To The Elements

Question: 

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?

Allowable Mold Levels For Indoor Air Quality

Question: 

Some questions have been raised regarding the levels of mold in the lumber used in one of our truss projects. The issue of indoor air quality is up and coming. Do you have any information regarding standard allowable values? And how can we test for these contaminants?

Health Hazards Of Mold On Lumber

Question: 

What are the health hazards of black fungus on Douglas-Fir lumber?

Gypsum Joint Ridging and Cracking

Drywall cracking and ridging are typical problems seen in ceilings and walls of homes. Sometimes, both of these issues appear at the same location, with cracking appearing in wetter months and ridging in drier months. This problem has become more widespread as homeowners insist on larger rooms and open floor plans that have large clear span areas. This Research Report evaluates local environment changes that play a significant role in every gypsum ridging and cracking case.

Designing for Damp Conditions

A truss designer who recognizes conditions that require a reduction in lumber or plate design properties can help ensure trusses perform as the building designer intends.

Using Trusses in Corrosive Environments

  • Standard metal connector plates are suitable for use in lumber with moisture content of 19 percent or less and in building applications with no exposure to corrosive substances.
  • Connector plates used in trusses exposed to high humidity or caustic chemicals may need to be treated to prevent corrosion.
  • A variety of protective coatings can be applied to truss places in situations where special protection is necessary.