Hi!
I have received a quote for free-spanning truss rafters.
View attachment takstol1.pdf
However, these are quite expensive (just over 3000:- each).
Now I have an idea to build my own according to the sketch in the quote, BUT to add an extra 45x220 at the bottom, so the bottom beam/intermediate beam becomes 45x440 in total. Otherwise, I would make it the same as the sketch.
But instead of using the metal fittings the truss factory uses, I would use plywood and nail glue.
What do you think about my idea? Is it risky to build your own trusses when they are so long?
It would be advantageous to have the intermediate floor higher to accommodate more insulation, 440 instead of 220, since the attic will be uninsulated.
Should I just drop the idea?
I have received a quote for free-spanning truss rafters.
View attachment takstol1.pdf
However, these are quite expensive (just over 3000:- each).
Now I have an idea to build my own according to the sketch in the quote, BUT to add an extra 45x220 at the bottom, so the bottom beam/intermediate beam becomes 45x440 in total. Otherwise, I would make it the same as the sketch.
But instead of using the metal fittings the truss factory uses, I would use plywood and nail glue.
What do you think about my idea? Is it risky to build your own trusses when they are so long?
It would be advantageous to have the intermediate floor higher to accommodate more insulation, 440 instead of 220, since the attic will be uninsulated.
Should I just drop the idea?
The price from the truss factory includes construction drawings and calculations. On the drawing you received, it specifically states that it cannot be used as a manufacturing template. That is, it is entirely possible that the truss will be manufactured with slightly different dimensions if you order.
Additionally, one must assume that the drawing you received is copyrighted, meaning you cannot use it as a basis even if it is correct.
The joint is a critical point. And you need a designer who can calculate whether your planned solution with plywood is as good as the nail plates the factory uses. I know that when calculating such things, specific patterns for nailing are prescribed, with about 100 nails in each plate. The shear load on such a plate can be several tons in a construction like this.
Building up the lower beam for more insulation, on the other hand, is not critical; you can likely do that with lighter timber than that.
Additionally, one must assume that the drawing you received is copyrighted, meaning you cannot use it as a basis even if it is correct.
The joint is a critical point. And you need a designer who can calculate whether your planned solution with plywood is as good as the nail plates the factory uses. I know that when calculating such things, specific patterns for nailing are prescribed, with about 100 nails in each plate. The shear load on such a plate can be several tons in a construction like this.
Building up the lower beam for more insulation, on the other hand, is not critical; you can likely do that with lighter timber than that.
A truss calculation costs about 5000:- and your municipality will probably require one.
I would think that you can save 1000:- per truss by doing it yourself. At least compared to that price which seems to be on the high side.
Why aren't they truss trusses if the attic is going to be unfinished? It should be significantly cheaper.
I would think that you can save 1000:- per truss by doing it yourself. At least compared to that price which seems to be on the high side.
Why aren't they truss trusses if the attic is going to be unfinished? It should be significantly cheaper.
The attic will be used for storage, but not heated... it feels stupid not to utilize such a large space.larsbj said:
It will become a garage and therefore needs to be free-standing to avoid posts. Then a staircase on the outside of the gable to the storage on the upper floor.
I don't need a building permit, so why would the municipality require a roof truss calculation then?
building thicker was to make it even more durable if one were to do it oneself, to be on the safe side, so to speak...hempularen said:
but as you say... the plates are probably very important to get correct.
regarding the copyright, I don't place any importance on it... I previously received a quote on the same ones, sent that "drawing" to this supplier who previously said they couldn't manufacture such large free-standing ones, and got a drawing with the exact same content but with their logo on it...
But you still need a calculation for the number of nails, right? Difficult to estimate yourself if you need 50 or 100 nails at a junction.thestrut said:
In my municipality, such a garage would require a building permit even if it's outside the detailed planning area, but it's somewhat up to the municipality.
My recommendation is to buy prefabricated ones, request prices from multiple manufacturers, you should be able to get down to around 2000:- /piece if you are getting 10 or more.
jaa it is very difficult to estimate the junction points, maybe the forum knows? =)
I will have 13 roof trusses and the price I got was including intermediate beams, that is, 9 meters long which will be between each truss to get cc600 to the floor. also including shipping. the trusses themselves cost 26600+VAT for 13 pcs, that is, 2557:- each. maybe it is not so excessive after all?
I will have 13 roof trusses and the price I got was including intermediate beams, that is, 9 meters long which will be between each truss to get cc600 to the floor. also including shipping. the trusses themselves cost 26600+VAT for 13 pcs, that is, 2557:- each. maybe it is not so excessive after all?
Here is probably info if you want to read. http://www.google.se/url?sa=t&rct=j...84LQAg&usg=AFQjCNHo6SbqI3sV-Z-6GYWRBogpYdzdDQ
But is that construction really sufficient to create a 9m spanning floor? I can accept that it works as a roof. But that you should also be able to load the collar beam with storage, I think that feels weak.
And then perhaps especially your intermediate beams which will not have a truss to hang on.
The trusses I have seen with such a long span have always been a truss model.
And then perhaps especially your intermediate beams which will not have a truss to hang on.
The trusses I have seen with such a long span have always been a truss model.
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Well, I know it exists, but I probably won't acquire it.
should hold for storage load with 100kg per m2 (1000 Newton was explained to me)hempularen said:
the intermediate beams should be hung on a board that runs along the "walls" of the knee walls/perpendicular to the truss direction, they are visible in the sketch.
Well, then you just have to trust that they are counting correctly.
Well, there are 2 that are similar, so it should be correct...
but 100 kg per m2, is that a little?
but 100 kg per m2, is that a little?
Good... then I can house the collection of cheva bigblocks there