Snow and Your Bowstring Trusses…Mortal Enemies

The most likely time for your trusses to fail is during a major snowstorm. 

The snow can add significant weight to your roof.  Snow and then rain are the worst combination possible.  A foot of snow can weigh 10-20 lbs per square foot of roof area.  One inch of rain absorbed by the snow can add an additional 5 lbs per square foot.  (current design snow load is 25 lbs per square foot, your 100-year-old building was very likely designed for less).  So, you can see this could be a problem. 

But you say, ‘My building is 100 yrs old and has seen everything, I’m not worried.  If it hasn’t failed in the last 100 years, why would it fail now?’

It has been a couple of years since we have had a major snowstorm in the Chicago area and things could have changed with your trusses since the last big snow. 

What could have changed:

• A roof leak could have rotted portions of your trusses.   
• Termites could have eaten portions of your trusses.
• A truss could have been damaged by impact by something…a forklift a truck.   
• Maybe someone decided to attach a chain fall to your truss to do some heavy lifting. 
• A small crack or imperfection in the wood could have worsened or could worsen with additional weight.

Any number of things could have happened to place your roof at risk.  So what do you do?  Call Wooden Roof Solutions for a free visual inspection of your bow string trusses and give yourself some peace of mind when the snow finally flies.