Does this roof truss look good?

[murak]

I have received quotes for trusses for a carport and they all look the same (W) but one stands out with a different construction, see image:



The following information was provided to the manufacturer in the request for quote:

Span: 6000 mm
Support width: 115 mm
Roof angle: 27 degrees
Snow load zone: 2.5
Outer roof: Heavy outer roof (concrete tiles, battens, felt, tongue and groove)
Inner roof: Light inner roof (tongue and groove or simple plasterboard)
CC: max 1200 mm

From what I can see, all suppliers have calculated the same loads for snow (2.5kN/m2) and inner/outer roof (0.3 / 0.65kN/m2)

Is the model in the image above worse in some way when compared to a "regular" W-truss? I also noted that the bottom chord had a dimension of 45x120mm while in all other quotes it was 45x145. Does the construction allow for using thinner timber without losing stability?

 

[Daniel 109]

I'm not an expert on roof trusses, but it almost looks like they counted on a support in the middle as well.

 

[murak]

I'm not an expert on roof trusses, but it almost looks like they also counted on a support in the middle.

Ok, no I'm not an expert either, but I reacted to the construction being different. I will double-check that it is self-supporting, i.e., two supports. Thanks for the quick reply!

 

[murak]

I called the manufacturer who was both friendly and helpful. The construction is properly dimensioned and it's slightly cheaper to build that way. However, I chose to switch to W trusses as it becomes easier to crawl around up there, and I changed the subframe to 45x145mm for a little extra security in case some insulation is thrown up there sometime in the future.