Cut, Modified or Damaged Roof Trusses

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Published: August 27, 2014 Last Updated: June 23, 2017
Roof truss cut or modified

One use of trusses is for the support of a roof, they are similar to roof rafters. Home owners should avoid cutting or modifying their roof trusses.  These trusses are usually engineered by a structural engineering company to carry a specific roof load. When a truss becomes damaged, cut or modified there is a chance of a structural overload or that they will not perform properly.

If a lot of trusses are damaged or one has been significantly modified or cut, then consulting a engineer is wise.

Who often cuts trusses ?

Home owners sometimes will cut trusses to make more storage space in the attic or to do other modifications or remodeling.

Furnaces are often located in attic areas. Replacement of these furnaces can be difficult and sometimes cannot be done without cutting or modifying a truss. Some HVAC contractors or installers may just cut a section of a truss out of the way in order to get their equipment into the attic.

Truss parts

Remodeling contractors

When home owners are remodeling their home they often want to move a wall, sometimes a load bearing wall. Doing this may result in one or more trusses cracking or getting damaged. This can lead to structural issues and occasionally the roof sagging.

Should a decision be made to modify a truss in order to raise the ceiling in an area, allow more storage or move a stairway, then it is wise to consult an engineer for assurances that there is no structural issues.


Truss repairs can be quite easy. If a part of a truss has been cut out, then replacing the board or piece cut out is generally not to hard or expensive. If a board is cracked, then placing a similar board on each side of the broken one and bolting or nailing the three together may correct the issue. Carpenters and framing contractors are the ones who often do this work.

Consulting with a qualified framing contractor or engineer can provide additional information.

Who to consult? Carpenters, framing and roof contractors; and occasionally an engineer.

The majority of time there is little work to do in order to repair a cracked or partially removed truss piece. Carpenters are the ones who usually do the repair work. Qualified handymen can likewise do many framing task.

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Hi, love your site and the search button really helped me out. The insulation salesman is making a *big deal* about the fact that rafters in our attic have cracks and have “sapped out”. Likely this is due to the wood drying out and thermal changes. The house is ~25 years old. Is this the *big deal* he’s making it? I feel like I’m being duped. Thanks so much for your answer!! ~Stephanie

Hi, I want to install ducted heating however i have a truss roof, is there a deducted heating unit that will fit to resolve for this issue.
Thanks Mark

I have been asked to get a report on the trusses in my house as when a valuation survey was done it stated that some parts of the trusses had been removed. This must have been before I bought the house but it didn’t show up in the survey from that time (2005). Who do I need to prepare the report for me. Thanks

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