Barn, can we change the roof trusses?

[Zilenser]

We have a barn that we would like to modify so that the trusses don't need the "triangle" down to the floor.
Are there solutions?


The barn is 12 meters wide and it's the red beams that we want to replace with another construction that doesn't encroach on the floor space. The walls are somewhere between 4-5 meters high before the roof. The barn is 40 meters long. The sketch is not to scale.


This is how it looks today. There is about 3.5 meters between the trusses.

 

[cpalm]

Simple answer: No. Not unless it involves more work than building a new barn.

 

[AG A]

Just like @cpalm writes, there is no possibility.

 

[Gimp]

Of course it works, a sufficiently thick glulam beam that alternates the diagonal braces, provided that the standing ones can handle the load themselves.

 

[Workingclasshero]

Of course it can be done, a sufficiently large glulam beam that transfers the load of the diagonal braces, assuming the vertical ones can handle the load themselves.

Nah, you'll need to elaborate on that a bit more.
/W

 

[Kurtivan]

I have a similar construction on my old barn, but there those braces stand on a wall plate about 1.5 m down on the wall posts, on top of that wall plate there are beams across and a floor on them. The beams are not only supporting the floor but also essential to keep the walls together and prevent them from being pushed out.

 

[Gimp]

Nah, you'll need to elaborate on that a bit better.
/W

To replace the braces, you "just" need to attach a glue-laminated beam between the vertical posts.
But I suspect you're aiming for the diagonal braces to also stabilize the entire structure laterally, so yes, that must be resolved as well. It can be done in a few different ways, e.g., stabilizing the short sides and crisscrossing between the trusses.

Edit: Of course, you should attach the diagonal braces to the new glue-laminated beam before cutting them.

 

[Gimp]

TS, if it's a serious thought, you should start with an engineer who can calculate the loads to give you an idea of the cost.

10 trusses to be built, checked glulam at Beijer and 90x315 should work if you place one on each side, i.e. 20 in total.
Just that is 150k.

Then it will be a challenge to get someone to guarantee that it holds, which I see as the biggest challenge that might derail the whole project.
Because if an engineer is going to calculate the fastenings in old logs, they probably want to cover themselves so that the carpenter doesn't screw in a lag screw right where the log is a bit rotten.

 

[Bjober]

The current truss stands firmly in the ground. It doesn't need a sturdy roof or wall.
Looking at the roof, you see boards in a direction that doesn't support the wall.
If you switch to the proposed truss, no stability remains in the structure. It becomes wobbly like a wet cardboard.

 

[Zilenser]

Thank you for all the answers. I'll have to think further about whether it is, as you say, an unreasonable thought 🥲 Dreaming is easy but then the money and reality have to align too 🤥

 

[Gimp]

The current truss stands firmly in the ground. It doesn't need a steady roof or wall.
If you look at the roof, you see boards in a direction that does not stabilize the wall.
If you switch to the proposed truss, there's no stability left in the structure. It will sway like a wet cardboard.

Yes, therefore you have to cross between the trusses and brace the short sides.

 

[Gimp]

Thanks for all the answers. I'll have to think further about whether it is, as you say, an unreasonable idea 🥲 Dreaming is easy, but then the money and reality have to align too 🤥

Yes, I think you'll have to weigh how much they are in the way versus the cost of even getting a quote and, in the next step, a quote for the job.

To brace the entire barn laterally, wind load calculations probably need to be done, so getting drawings ready to request a quote might run up to 50-100k.

A rough guess from me who likes to guess too low because I dislike paying too much...

Material
Laminated beams crosswise, 150k
Laminated beams crisscross, 150k
Bracing end walls and metal brackets/screws 50k

Labor
2 people for 4 weeks, about 750:-/h 240k
2 all-terrain scissor lifts for 4 weeks, guessing 50k
Some kind of loading machine or similar 20k

So I think it will end up costing quite a bit.