Carpenter wants to use OSB Floor trusses ?

[Windpower]

My carpenter wants to use floor trusses -- the OSBoard thingies with dimentional caps -- instead of regular 14 '  2 X 10's with a laminated beam in the center

he says they are cheaper and don't require blocking -- even more cheaper

(I don't like OSB -- just my opinion    )

it is a 28' span for the floor of the apartment above the 3 car garage

opinions ?   

(Foundation hopefuly going in week after next 

[MountainDon]

Those things, and open web trusses similar to roof trusses, are used all over the place. Here they actually use the open web truss more than the other. When they are sized right by the engineer I can't tell I'm walking on a floor built with them. In a fire they are toast very quick; that's one bad downside. If kept dry they're probably okay. Those both eliminate the center beam which can be nice. Between the two I like the floor truss better only because they make it easier to run ducts, pipes, etc at any later date.   

[flyingvan]

   If you're talking about TJI's I was very hesitant to use them for my current build---I love the look of all those joists lined up perfectly.  They were so easy to work with, though, and I could hang them between beams from nifty hangers that took 12" off my overall height...They are straight and can span great distances.  If you are careful to always cut the same end and always put that cut end on the same side of the wall, the little knock outs for piping and electrical line up perfectly.  Don't try to walk across them without bracing---very wobbly left to right until you get them tacked down.  They need to meet up with a rimjoist that can support walls wt the ends, don't rely on their compressive strength for that (you can block the ends too like I did)  Also if a wall is going parallel plan it so you can double up two tji's under the wall, insulate as you go.
   They make ending up with a perfectly flat floor easy with no planing od bowing or twisting dimensional lumber.  My big fear is finding out in thirty years the adhesives in the OSB turn to dust and the TJI's just fail.  DOn's sure right about quick failure during a fire.  We're starting to see injuries from them

[speedfunk]

I personally think that its junk construction.  Do you really want your house held up by chips of wood and glue. 

Just my opinion.

[ColchesterCabin]

Here on the east coast of Canada they are common as we are quicly running out the size wood required to make the proper dimensional lumber. It isn't like they are not engineered. The benefit of that is someone else assumes any liabiliies per say pending instalation is correct. They would go up quick in a fire, however, if you are not out by the time those light up and crumble you and anyone else wouldn't have survived anyways, being a volunteer firefighter for 13 years. IMO!

[MushCreek]

I used them on my build, mostly because of the poor quality of dimensional lumber. I had one 2X12 crown almost an inch! The TJI's are dead straight and very solid feeling. As for fire safety, I plan on going double 1/2 inch drywall for a ceiling, which gives a one hour fire rating, and also helps isolate noise between floors. I don't know why your carpenter said they were cheaper; when I did mine this summer, the TJI's were about 20% more, although there would be a little labor savings perhaps.

[Alan Gage]

I don't know why your carpenter said they were cheaper; when I did mine this summer, the TJI's were about 20% more, although there would be a little labor savings perhaps.

I'd guess the carpenter meant cheaper when compared to traditional floor trusses.

Alan