Bolt in wood joint, minimum anchorage length?

[Ahmada]

Isn't it enough to just add a new roof truss in line with the existing truss and connect them with nail plates (wooden braces) and some anchor screws?

I don't know if this will work, as the existing truss is cc1200mm and the new roof beam is cc600mm. One on each side of the truss. Since all the timber has a thickness of 45mm, I'm not sure how to align them properly.

 

[prototypen]

Through bolt and nut tend to become loose.
The hole must be slightly larger than the bolt, and if it moves, the hole will become larger.
Then, wood shrinks and swells, causing the preload on the screw joint to be lost, and in this case, it can be difficult to retighten the joint.

Wood screws and nails work better.

Protte

 

[prototypen]

I don't know if this works, as the existing truss is cc1200mm and the new roof beam is cc600mm. There will be one on each side of the truss. Since all timber is 45mm thick, I don't know how to align it?

How are you thinking there?
You're going to add twice as many roof joists and place two on each side of the truss, then it will be CC 90 mm......and to the next roof tile, they will be CC...1110 mm??

Or am I misunderstanding something.

Why are you called Ahmada sometimes and HEA other times??

Protte

 

[Ahmada]

Through bolts and nuts tend to become loose.
The hole must be a little larger than the bolt, and if it moves, the hole will become larger.
Then the wood shrinks, swells and you lose the preload on the screw joint, and in this case, it can be difficult to retighten the joint.

Wood screws and nails work better.

Protte

I am trying to calculate for wood screws instead.

 

[Ahmada]

How do you think there?
You are going to put in twice as many roof battens and place two on each side of the rafter, then it will be CC 90 mm......and to the next roof tile it will be CC.........1110 mm ??

Or am I misunderstanding something.

Why are you called Ahmada sometimes and HEA sometimes??

Protte

No, you didn't misunderstand anything, but the area that the roof beam takes load from the roof will be the same as for cc600. That is, instead of 300mm from each side (a total of 600mm), it takes almost 0 from one side and about 600mm from the other side. Then you have to assemble the roof beams with screws and timber between or something similar.

I'm helping someone who bought materials before the design was done for the current project, hence the non-traditional solution.

Apparently logged into different accounts on computer/mobile. I didn't know this myself, sorry for any confusion it caused.

 

[bossespecial]

I don't know if this works, since the existing truss is cc1200mm and the new roof beams are cc600mm. There will be one on each side of the truss. Since all timber has a thickness of 45mm, I don't know how to get it flush?

Since the new roof joists will be placed on the outer wall, it's enough to only connect every other one horizontally to the truss. The intermediate joists that are only supported on the wall plate are then braced by the roof sheathing.

 

[Ahmada]

Since the new rafters will be placed on the outer wall, it's sufficient that only every other one is connected horizontally to the truss. The intermediate rafters, which are only mounted on the wall plate, are then braced by the sheathing.

Good idea, I can imagine this could work. Thanks! I'll think more about it.