Homemade light beams

[Anton Olofsson4]

I have now started printing my updated beams, which can be seen here. [link]

In the first ones, I used construction timber (C24), 45x95, which I split to 70 mm to fit the thickness of the XPS insulation. In the new version, I tried splitting up Lvl (Kerto) beams. The beam was originally 51x400x4000, which I later split to 51x45x4000. The reason for choosing Lvl was that they are significantly more dimensionally stable and therefore easier to handle. So far, I have printed 4 beams with OSB as the core and have very good repeatability on my attempts. I will print two beams where the core consists of 12 mm k-plywood for comparison. More information will come when time permits.

Nice to see!

Have you come up with any model you want to use yourself for construction?
Thinking about price/durability/construction time, etc. Which model do you think is the best?

 

[Per Lindh]

Hello,
I will choose lvl which I cut to suitable dimensions and then 11 mm OSB, but likely replace XPS with PIR as it has better fire performance, OSB provided better performance than plywood. Since the beams won't be visible, OSB seems best for performance/price.

I am now working on a truss beam made of plywood which I prestress with a smooth reinforcing bar at the bottom. This variant will be visible, and therefore the appearance becomes a little more important.

 

[Per Lindh]

Hello,
I will choose lvl which I will cut to suitable dimensions and then 11 mm OSB but probably replace XPS with PIR as it has better fire resistance, OSB gave better performance than plywood. Since the beams will not be visible, OSB feels best in terms of performance/price.

I am now working on a truss of plywood that I prestress with a smooth rebar at the bottom. This variant will be visible and therefore the appearance is somewhat more important.

A little Easter DIY. Lightweight consisting of 12 mm k-plywood in the center and then 21 mm k-plywood on either side. The panel is designed to take compression in the struts and at the bottom which takes tension I have a 12 mm steel where I threaded the ends to be able to prestress the beam slightly. Probably a pressure test this spring.

 

[Per Lindh]

Some Easter crafting. A light beam consisting of 12 mm k-plywood in the center and then 21 mm k-plywood on both sides. The compartment is designed to handle pressure in the struts, and at the bottom, which handles tension, I have a 12 mm steel where I have threaded the ends to be able to pre-tension the beam slightly. There will probably be a pressure test in the spring.

 

[Anton Olofsson4]

Some Easter crafting. Easy to make consisting of 12 mm k-plywood in the center and then 21 mm k-plywood on both sides. The compartment is designed to take pressure in the struts and at the bottom where tension is applied, I have a 12 mm steel where I have threaded the ends to be able to preload the beam a bit. There will probably be a test press in the spring.

Hi,

Do you have a picture of it?
A few questions;
Split LVL/kertobalkar I understand that both are more dimensionally stable and durable but it becomes much more expensive than, for example, using 45x70 inside the beam. What do you think about that?
Does it matter if the short studs in the beam are placed inside the long ones or on top for durability? Are there any advantages or disadvantages to how they are placed?

 

[Per Lindh]

Hi,

Do you have a picture of it?
A few questions;
I understand that split LVL/Kerto beams are both more shape-stable and durable, but it becomes much more expensive than, for example, using 45x70 inside the beam. What do you think about that?
Does it matter if the short studs in the beam are inside the long ones or on top for durability? Are there any advantages or disadvantages to how they are placed?

Of course, 45x70 will be cheaper than the corresponding LVL beam. The advantage of LVL is that it is 51 mm and it fits perfectly with gluing 50 mm PIR or XPS. Attaching a picture of the different types.

 

[Anton Olofsson4]

Of course, 45x70 will be cheaper than the equivalent lvl beam. The advantage of lvl is that it's 51 mm, which perfectly fits gluing 50 mm pir or xps. Attaching an image of the different types.

I see. What kind of lvl beam are you splitting? Found any affordable options?
I thought that there is a lot of different 45mm insulation if you use studs.

 

[Per Lindh]

I understand. What kind of lvl beam are you splitting? Found any affordable options?
I thought there is a lot of different 45mm insulation if you're using studs.

I bought Kertobalk 51x400. When I used C24 timber, I bought 45x95 which I sawed down to 45x71 to make some room for glue. I used PU glue because it glues plastic, wood, metal, etcetera. PU is also enhancing and has a good open time, around 30 min. However, the result depends on good press pressure during curing.

 

[Majskaka]

Hi,
I will choose lvl which I split to a suitable dimension and then 11 mm OSB, but will probably replace XPS with PIR since it has better fire standard, OSB gave better performance than plywood. Since the beams won't be visible, OSB seems best in terms of performance/price.

I'm currently working on a truss beam made of plywood which I pre-stress with a smooth rebar at the bottom. This variant will be visible, so appearance is a bit more important.

How do you handle OSB if you want a longer beam than 3m? It's probably not a good idea to splice in length, right?

 

[Per Lindh]

How do you do with OSB if you want a beam longer than 3m? It's probably not good to splice on the length?

The ones I made were four meters and I used 2.5-meter OSB. Stagger the joints between the sides. On plywood, it worked well to use a variant of "double lap joint" but it is not necessary.

 

[Majskaka]

The ones I made were four meters, and I used 2.5 meters OSB. Offset the joints between the sides. For plywood, it was fine to use a variant of "double lap joint," but it's not necessary.

Okay, great! There shouldn't be too much load on the panels either, it's the "reglarna" that should take it. I also saw that Kerto also makes LVL beams if you want to avoid splitting the beam yourself.

 

[Anton Olofsson4]

The ones I made were four meters and I used 2.5 meters OSB. Offset the joints between the sides. For plywood, it worked well to use a variant of the "double lap joint" but it is not necessary.

Hi Per,
How has it gone, have you started making anything?

 

[Anton Olofsson4]

Hi Per,
How has it been going, have you started manufacturing anything?

How has it been going with this?

 

[vanpire]

Peeked around a bit and found these:
https://ibjoist.com/
Looks very cheap but probably depends on the shipping cost.

 

[Per Lindh]

How did it go with this?

Hi Anton,
I've been a bit too busy, but now I've made some vippskydd so that I can at least test my truss beams made of plywood. The beams are reinforced with a steel rod at the bottom edge.