Roof Truss: Can You Cut Through It?

A roof truss is a complex structural element of a building. Registered engineers in almost all situations design this, and you should never cut any part of the truss without consulting an engineer first. 

Building codes prohibit notching or cutting of roof trusses. This is because once you cut into any part of the roof truss, you can no longer trust its integrity. You may have to cut through one or two roof trusses to frame out the opening.

Is it OK to Cut a Roof Truss?

Homeowners should never cut or modify their roof trusses. A structural engineering company usually engineers these trusses to carry a specific roof load. When a roof truss becomes damaged, cut, or modified, there’s a chance of a structural overload or that they will not perform well.

How Do You Support a Roof Struss

Placing a 2-by-4 inch piece of lumber from each truss on one side to the truss on the other can provide extra support for the trusses. This should be high enough to provide headroom but low enough support for the trusses. In this case, the walls of a finished attic space or room would go with the roofline.

Can You Modify the Trusses?

Modifying the roof truss is an enormous amount of work. If you feel you’ll be sliding new larger common rafters up inside the attic alongside the existing trusses, you’re wrong. Instead, you’ll have shingle nails in your way extending through the roof sheathing.

Can You Convert Trusses’ Rafters?

Converting a standard truss into an attic truss attic is possible by replacing the truss rafters with A-shaped trusses or horizontal beams, which can create additional space.

Why Do Some People Want to Cut a Roof Truss?

Some homeowners want to cut their roof truss to make more storage space in the attic or to do other modifications or remodeling. However, we don’t advise them to do it independently as it’s risky; hence, they need to consult a structural engineer.

Furnaces are often located in attic areas. Replacement of these furnaces can be difficult and cannot be done without cutting or modifying the roof truss.

Some HVAC contractors or installers may just cut a truss section to get their equipment into the attic. 

Remodeling Contractors

When homeowners are remodeling their homes, they often want to move a wall and a load-bearing wall. However, doing this can result in one or more trusses cracking or getting damaged. This can lead to structural issues and roof sagging.

Should you plan to modify your roof truss to raise the ceiling in your area, move a stairway, or allow more storage, then it’s wise to consult an engineer for assurances that there are no structural and roof sagging issues.

How Can Effective Building & Consultancy Help You With Roof Truss?

Truss repairs can be quite easy. If a part of the truss has been cut out, replacing the piece cut out or the board is not too complex or expensive.

If the 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. Building inspectors, contractors, and carpenters are the ones who often do this work. 

Consulting with Effective Building & Consultancy’s qualified structural engineer, Elie Farah, and our team of building inspectors can provide additional information. We know what work should be done to repair or cut a truss piece.

For more information about our building inspection services, visit our Help Centre. Alternatively, you may also call us at 02 9613 3353.