Cutting an existing roof truss for an extension
Cutting an existing roof truss for an extension
(OP)
I am currently looking at a small project that requires a large section of the roof truss to be cut to allow a second floor extension to be built.
I don't normally work on residential sized projects and therefore I require some general assistance and direction with this.
The image below shows the section that is proposed to be cut with the remainder of the truss to remain in place.
My logic is to provide even support to the top chord by introducing two additional webs as well as ensuring the existing web is replaced for a longer section that is fixed to the base of the new vertical studs(which forms part of the external wall of the extension).
At this stage it is a high level assessment without looking at specific calculations.
Any general advice, comments or solutions would be much appreciated.
I don't normally work on residential sized projects and therefore I require some general assistance and direction with this.
The image below shows the section that is proposed to be cut with the remainder of the truss to remain in place.
My logic is to provide even support to the top chord by introducing two additional webs as well as ensuring the existing web is replaced for a longer section that is fixed to the base of the new vertical studs(which forms part of the external wall of the extension).
At this stage it is a high level assessment without looking at specific calculations.
Any general advice, comments or solutions would be much appreciated.






RE: Cutting an existing roof truss for an extension
RE: Cutting an existing roof truss for an extension
RE: Cutting an existing roof truss for an extension
If the renovation is extensive (kitchen being gutted and replaced) I would probably remove the entire truss and replace with new. Timber trusses are fairly cheap and easy to work with - by the time you shore up the existing truss and reinforce/rebuild in place, you may as well just buy new trusses. The new trusses will go in just as fast as you can reinforce the existing and then you don't have to work around half a roof truss while you build the new upper floor.
I've been involved in many renovations, and more often than not, trying to save a portion of the existing structure like this is more trouble than its worth.
RE: Cutting an existing roof truss for an extension
RE: Cutting an existing roof truss for an extension
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Cutting an existing roof truss for an extension
RE: Cutting an existing roof truss for an extension