Trusses that are sagging

[M@ZE]

Did a quick test and stretched mason's line around the brackets. The length between is 2120mm and it bends 5mm. Would need to measure the full span. But there are some others that look worse by eye.

 

[RapidSledge]

Did a quick test and stretched mason's line around the stays. In length between, it is 2120mm and it bends 5mm. Would need to measure over the entire span. But there are some others that look worse to the eye.

Looks like the carpenter who screwed in the anchor screw was confused about which holes he should use.

 

[M@ZE]

Looks like the carpenter who screwed in the anchor screw got confused about which holes to use.

Haha feels a bit random, put on the blindfold and screw

 

[multix]

If I understand the problem correctly, it is the ceiling that is sagging. If the bottom edges of the intermediate beams are shifted toward the middle (red arrows) by a few centimeters, the ceiling will be lifted (green arrow upward). That's how I would do it, it costs 0 kronor. But it probably requires loosening some anchor screws at the top as well due to the heavy timber in the intermediate beams that counteracts the twisting. Definitely, you need to apply pressure from below during the reconstruction to support the ceiling, otherwise, you won't be able to realign the trusses. One truss at a time.

Additionally, they should be more level and be supplemented with trusses toward the ridge to prevent the outer roof from being pulled downward (green arrows downward). See images from takstolsfabriken in Sjöbo. The carpenters are probably skilled carpenters, but when it comes to truss construction, they should have sought help. Unnecessarily heavy intermediate beams otherwise.

 

[M@ZE]

Hmm what happened to the pictures?

 

[M@ZE]

Do you have any tips on how to proceed with using a brace to get the rafters plumb before screwing in my finger-jointed 6.5m 45x145 into the lower chord of the rafters?

And then it will be time to buy 56x225 glued laminated timber and try to install it. How should they be attached to the wall plate? Angle brackets?

 

[justusandersson]

Rent steel props at Cramo or a similar place. They are tightened using a handle that screws up.

How should they be fastened to the wall plate? Angle iron?

Yes.

 

[M@ZE]

Rent steel props at Cramo or a similar place. You tension them using a handle that screws up.

Yes.

Thanks

I feel like I'm not quite sure how to align them vertically though

 

[justusandersson]

Don't you mean in level? Use your laser measure. If it's the sag in the middle that you need to lift, start by measuring the height next to the outer walls.

 

[M@ZE]

Don't you mean level? Use your laser measure. If it's the sag in the middle you're trying to push up, start by measuring the height next to the exterior walls.

Yes, level

Measure from the floor up to the underside of the armrest on the sides along the wall and then in the middle?

 

[justusandersson]

Yes. Note that it is called underram.

 

[M@ZE]

Yes. Note that it's called underram.

I measured from the floor to the underarm first on both sides

2590mm
2592mm
middle 2572mm

Whether the concrete slab is completely level is another question 🙈

 

[justusandersson]

The slab is certainly not completely flat, but this is not science either. A deflection of 20 mm without load just due to its own weight is way too much.

 

[M@ZE]

The board is probably not completely flat, but this is also not science. 20 mm deflection without load just due to its own weight is way too much.

I agree with you, it sounds like a lot and now without the snow load. Do you think it can be fixed by screwing in the finger joints when they are aligned?

The strange thing is that you don't see any obvious gap at the seam itself.

 

[justusandersson]

Do you think you can fix it by screwing into the finger joints when they are level?

If it's just about deflection due to the subframe's own weight, then it's not a solution, since it increases proportionally. However, the construction can handle a greater load. Note that I have never suggested this because I believe the measure is theoretically pointless. At the same time, I must admit that 20 mm is a significantly larger figure than one would calculate. In a thread discussion like this, you can only advocate for a solution you believe in; arguing against others' proposals just becomes tedious. TS must evaluate the posts themselves.