Replace k24 beam with glulam?

[olofh]

I have received the suggestion to put together 2 pcs of k24 45x170 to support a smaller opening (3m). I'm wondering if I can replace this with a glulam beam because it's a bit nicer. What dimension would this correspond to? 2 x 45x170 is reportedly very well sized and 145 would also work but you know how it is with the home builder's belt and suspenders. Snow load zone 1.

 

[justusandersson]

The closest glulam to double C 24 45x170 is 66x180, which will be slightly stiffer.

 

[olofh]

And closest double c24 45x145?

 

[justusandersson]

42x180.

 

[olofh]

42x180.

Aha! Thought I could lower the height so to speak, but maybe it's not possible

the building store thought 90x90 could correspond to 45x145 but didn't get a good feeling for the salesperson...

 

[justusandersson]

No, if he suggested 90x90 then he doesn't know much about strength... The problem with glued laminated timber is that 180 is normally the minimum height. If you choose a type of glued laminated timber that is homogeneous, you can cut it down to the desired height yourself. What height do you wish for?

 

[olofh]

As low as possible, so to speak
No, but a maximum of 145, preferably a bit lower would have been nice

 

[olofh]

Edit. Will try to contact the designer tomorrow. Originally he said 2x145, but when he got back it was 2x170 with the comment that it is really generously calculated.

 

[justusandersson]

If you buy a homogeneous glulam beam that is 115x270 and split it in half, it works. Likewise, a 78x180 that you split down to 145.

 

[olofh]

If you buy a homogeneous glulam beam that is 115x270 and split it in half, it works. Similarly, a 78x180 that you split down to 145.

Thanks. I'll have to check the costs etc. to see if it's justifiable. Can you split it with a plunge saw or is it the lumber dealer who does that?

 

[justusandersson]

It is probably best if the timber merchant does it with a proper panel saw. My plunge saw can only handle about 55 mm depth. There are models that can handle 75 mm, but that's probably the limit. The guide rail adds about 6 mm as well.

 

[olofh]

It's probably best if the wood dealer does it with a proper panel saw. My plunge saw only handles about 55 mm depth. There are models that can handle 75 mm, but that's probably the limit. The guide rail also adds about 6 mm.

I was wondering what you think about my colleague's suggestion to take 2 pieces of 42x180, cut down to 145, and join them together? Mostly because 42x180 is a stocked dimension.

 

[justusandersson]

Yes, two 42x180 cut down to 145 works.