Category Archives: Wood

An Oversight Makes a Rafter More Susceptible to Fracture

Posted by in Construction & Shortcuts, Roof, Structural Analysis, Wood | December 07, 2015

In the featured photograph we see where the rafter fractured at its end.  This fracture was due to vertical tension in the rafter.  That is, the weight of the roof framing and the snow were pushing downward along the length… Read More →

What is causing the cracking in my ceiling?

Posted by in Wood | October 12, 2015

We have looked at numerous single-family ranch style dwellings constructed in the 1960s where the ceiling exhibits cracking between the dining room and the living room.  It’s a crack that emanates from the corner of two walls.  Those of you… Read More →

What Can Happen to Unbraced Wood Truss Web Members?

Posted by in Construction & Shortcuts, Structural terms, Wood | September 21, 2015

So, what happens when the web members of a wood truss are not braced laterally as specified by the truss manufacturer? When a wood truss is designed and constructed by a truss manufacturer, the manufacturer commonly provides drawings that show… Read More →

What Can We Tell from This Photo? (Case Study 9)

Posted by in Fire Damage, Simple Forensic Methods, Wood | August 03, 2015

What can we tell from THIS photo? The wood plates and staples indicate that these are very old field built wood trusses. The soot and char indicate that they have been exposed to a fire. The relatively clean separation between… Read More →

How many layers of shingles?

Posted by in Roof, Shingles, Wood | June 22, 2015

How many layers of shingles can be safely supported on a wood framed residential roof? Most building codes limit the number of layers of shingles to two.  As a structural engineer, I design for two, but I prefer one layer… Read More →

What Can We Tell from This Photo? (Case Study 6)

Posted by in Simple Forensic Methods, Wood | April 06, 2015

  During our moisture source evaluations we sometimes observe other conditions that we bring to the attention of the owner.  Such is the case for this week’s topic. In the featured photo and Figure FT-1 we see a fractured web… Read More →

How Much Snow Can My Roof Support?

Posted by in Roof, Snow Loads, Winter Concerns, Wood | March 02, 2015

After a succession of heavy snowfalls, we are often asked the question, “How much snow can a roof support?” or more specifically, “How much snow can MY roof support?” and “Should I shovel the snow off my roof?” Most who… Read More →

Sawing Off the Limb You Are Standing On

Posted by in Roof, The Unusual, Wood | February 02, 2015

Many of us have heard the expression, “You are sawing off the limb you are standing on.”  Often someone will say this during a friendly debate when the other debater is undermining his own argument by discrediting his own evidence.… Read More →