You can "arm" with a suitable fully threaded construction screw.
There are usually free dimensioning programs on the supplier's website. For example, Heco Germany, fischer.
Reviving this thread because I'm considering doing a similar construction with cutouts in glulam beams. This is to avoid joist hangers and create an elegant stud construction for a loft structure indoors.
No one responded to the comment above. Shouldn't it be possible to maintain most of the load-bearing capacity by skew screwing ("arming") like this?
The load-bearing capacity of a beam is mainly determined by the cross-section in the middle, much less at the support.
However, you should ensure that the beam does not split at the corners of the recess. Place some vertical wood screws from above there.
Don't screw. Nail. Screws have poor shear strength.
The problem with that construction is that if you have large loads near the wall, the shear strength can become critical. In plain terms, it means that the beam could crack from the bottom of the notch. I don't think it will be critical in your case but it's important to be aware of the risk.
If you have sized the floor beam correctly for deflection, shear force usually doesn't become a problem with smaller notches. But I wouldn't take a chance without calculating whether it holds for the shear force.
How about the load beam, are you making the notches directly over a post? Otherwise, you might encounter problems if it's between two posts.
Don't screw. Nail. Screws have poor shear strength.
The problem with that construction is if you have large loads near the wall, the shear strength can become critical. In clear terms, that means the beam cracks from the bottom of the notch. I don't think it will be critical in your case, but one needs to be aware of the risk.
Ok. Thanks for the tip. I think that risk has already been mentioned earlier in the thread and I understand that it can be partly remedied through "reinforcement."
If you have sized the floor joist correctly for deflection, shear force usually isn't a problem with smaller notches. However, I wouldn't take a chance without calculating that it holds for the shear force.
How about the beam, are you making the notches directly above a post? Otherwise, you might have problems if it is between two posts.
As mentioned, it's a question of constructing a loft in a room with a ceiling height of about 5.5 meters (think of it as an extra floor level). Two of the walls are concrete and the third is plaster with plywood behind it.
The size of the loft will be approximately 3.90x3.75 m, with the beams being free-hanging about 3.75 m. According to the TräGuiden's calculation program, 56x225 mm glulam beams at cc 60 should be sufficient to achieve adequate load-bearing capacity, at least without notches.
The plan is to attach the beam directly to the wall. Deflection should not then be a problem.
Unlike the original poster, I could of course lower the beam to avoid notches. But I think that notches would be a slightly more elegant solution. 🙂
Edit: And yes, the smartest thing is of course to calculate. But it feels difficult to reliably do so unless you work with strength calculations. So the question becomes more about what overall risks you are taking and if there are standard solutions to mitigate these risks.
I would advise against carrying out this notch unless you can calculate it. You will likely significantly reduce the capacity. See "Dimensioning of Timber Structures - Part 2" chapter 8.3 if you feel like delving deeper into this. It is available for free download.
Do not screw. Nail. Screws have poor shear strength.
The problem with that construction is that if you have large loads near the wall, the shear strength can become critical. This means in plain language that the beam cracks from the bottom of the notch. I don't think it will be critical in your case, but one needs to be aware of the risk.
That's why you toe-screw so that it becomes tensile load instead of shear load.
The load-bearing capacity of a beam is mainly determined by the cross-section in the middle, much less at the support.
[image]
However, make sure that the beam does not split at the cut-out corners. Place some vertical wood screws from above there.
But now it's not about the load-bearing capacity in the middle. It's about the support. There you cannot compare regular construction timber with steel.
If such a cut-out is to be made, the entire support must be reinforced with steel. Otherwise, the beam risks cracking, breaking at the cut-out, or essentially being crushed/mushed at the support.
Ok. Thanks for all the valuable input. Upon further consideration, it will likely be a solution where the bearer beam is moved down instead and the notches are skipped.
Click here to reply
Vi vill skicka notiser för ämnen du bevakar och händelser som berör dig.
Nicro said:
