Charring Of Trusses


Our home caught fire last month and burned partly through a tongue and groove ceiling to the trusses. Some are charred. Our contractor did a moisture meter test. An engineer for the insurance company said the trusses were only smoke damaged & the moisture meter test is invalid (it can be set to read anything). I found one article on charred trusses, but it’s pretty vague. We do not feel safe with the insurance engineer’s assessment because some of the trusses are obviously charred. We hired an engineer who agreed with us. The insurance is refusing to pay for repair/replacement of any of the trusses. Do you have any more info on this type of problem?


Every engineer has their own way of determining how structurally sound a fire-damaged truss is. Some see evidence of char and fail the truss. Others consider the residual strength based on the amount of charring and proximity to a joint. It really is up to the individual inspecting the trusses. The real question is not how much charring you can see but whether your engineer has determined that the trusses are structurally unsound. Trusses may be charred, but if the charring occurs in an area of the truss that is over-designed (which can certainly be the case), it may not affect the design strength of the truss. The trick is to know enough about the trusses to understand where these areas of the truss are located. For more information on trusses and fire performance, see the fire section of SBCA’s website.

SBCA Categories: