ᐅ Clamps in the rafter roof: Is removal possible and safe?

Hello everyone,

I’m new here. We have bought a house from 1980 with a rafter roof featuring a ridge beam, a central purlin, and a wall plate still in their original condition. New insulation is currently being installed between the rafters. At that time, large rooms were built under the sloping roof, with a partially horizontal ceiling beneath the collar beams. In fact, all rafters above the room are connected by double collar beams.

My question: Do these collar beams have a structural function, or are they only there to support the ceiling construction? We are now considering the possibility of removing the collar beams and extending the roof slopes all the way up to the ridge beam. This would keep the window openings in the masonry intact and prevent the upper part of the trapezoidal windows from being cut off.

Do the collar beams hold the rafters together and keep them vertically aligned (cross-section 8 x 180mm (0.3 x 7 inches))? Our carpenter told us that "back then, they liked to use a lot of wood"... Is there any risk in doing without these double collar beams?

Thanks for your time and help!
Bruno

I am not a structural engineer; only they can give a definitive answer on this, but to me, it looks like the collar ties transfer the load from the ridge beam into the rafters in a way similar to a suspension bridge principle, and otherwise, the ridge beam would need supports standing in the middle of the room. So, I would not simply remove them.

Good morning,
Thank you, Tolentino.
For your information: The ridge beam is not supported by the collar ties at all. The collar ties only connect the rafters in pairs.

Any other opinions on the function of the collar ties in this case?

Thank you.

These parts are also called ridge straps and are a structurally necessary element. According to a reliable search engine: they serve to stiffen the rafters, absorbing both tension and compression forces acting on them.

There might be alternatives, but a structural engineer or carpenter can advise you. I wouldn’t recommend removing them without professional guidance.

Many thanks to both of you.
It helps me a lot.
I will give up on the pliers and actually look for alternatives.

Thank you very much!
I wish you a great day.
Bruno

There must have been some reasoning behind the effort back then. A structural engineer can recalculate whether the braces are redundant with the belt. Which is what I almost suspect.