Hello.
My roof trusses in the garage are supposed to handle 100kg/m2 according to the manufacturer, as I plan to have a storage loft up there.
There are 9 distributed over 8.4m.
I have now added beams (collar beams?) between the trusses, the span is 6m, the additional beams are 45x170 and overlap by 1.80, glued with PU glue and screwed together with 16 5x90 screws from each side.
The existing trusses are joined in the middle with a nail plate on each side, and I figured I'd screw and glue an additional 45x170 on these as well.
Today I added extra "legs" outside the existing ones, see picture. these are also secured with PU glue + 5x90 screws.
Is it safe to guess that I can now stack 200kg/m2 on the loft?
Hi
My spontaneous feeling says no. The pressure on the lower beam won't decrease by supporting the post there. Rather, you should place 1 upright beam between each post. That is, you use the same dimension as the lower beam in the truss so the c/c measurement becomes smaller.
Yes, I added an extra beam between each, these are the ones overlapping by 180cm. I don't know where the center-to-center (CC) ended up now, but I believe it's about 50-55cm now.
150kg/m2 now maybe?
100 is enough in theory, but you want to have the margins on the right side!
Maybe a bit advanced, but the load should also be taken up by the wall – whether it can withstand the load, meaning the increased weight on the structure (more beams, etc.) + what you plan to put in the loft.
Better to have light things up and heavy things down in a garage... one quickly gets tired of lifting heavy things up or down even if one has a crane...
Can you place a rule (e.g. 45x120) on its edge at the rafters and attach the extra joists to this with a hanging 45x45? That would significantly reduce the span.
A 45x170 helps almost nothing with a 6m span.
Raising this a bit as I'm considering another reinforcement idea
Hope it's possible to see in the picture how I was thinking. Would this be of any use?
My interpretation:
Placing a vertical rule at the support legs has approximately the same effect as cross-bracing.
That is, it locally reduces the deflection in the floor structure, allowing it to bear more point loads than without the "reinforcement."
But it does not increase the total load-bearing capacity of the floor structure.
Is it impossible to insert a couple of columns and a beam in the middle of the span?
Truss frameworks are designed to have supports in the middle.
I don't know how much space you have downward, but one idea is to place a 145 under each underarm so that the thickness becomes 170+145=315. Then screw and glue plywood on both sides of these. Place the plywood with staggered seams.
This provides significantly better load-bearing capacity for the entire structure.
I don't know how much space you have downward, but one idea is to place a 145 under each forearm so that the thickness becomes 170+145=315. Then screw and glue plywood on both sides of these. Set the plywood with staggered joints. Gives significantly better load-bearing capacity to the entire construction.
In that case, don't forget to check the load-bearing capacity of the wall studs!
Hello. The underarms are just 145x45, not 170... The idea of an extra under sounds good. The trusses rest on 250mm leca wall and 145x45 hammarband, no wall studs. The "strange" thing is that the loft feels very stable, not a hint of sagging or creaking when I (140kg) walk around up there.....
