Floor Truss system

[danna]

I have another question, alot of the modular homes are being built now with a floor truss system. The ones we've seen are made of 2x2 lumber . Does anyone have any experience with these new floor trusses they're using ?
And I wanted to thank everyone for the replies to my other post. We've got one of the builders willing to upgrade to plywood floors now. Anyone that won't, gets crossed off the list. Thanks. danna

[trmimo]

The most commonly used truss is the open joist by universal forest products.
It is much straighter than a 2 by 10 joist.
the webs are 2 by 2's and the top and bottom flanges are 2 by 3s.
It is also easier to install plumbing and ductwork.
The manufacturers like them because the extra strength allows them to place them on 19.2" centers instead of 16" centers which uses less material and saves labor.
However, my experience has been that you will notice quite a bit of vibration in the floor with the 19.2" centers.
You can correct this by drywalling the basement ceiling. The drywall stiffens the truss and absorbs vibration.
There is quite a bit of information available online at www.ufpi.com

[Fred]

I saw where you can drywall a basement ceiling. But what about mobile homes with no basement? How do you shore it up then? What type of bracing?

[trmimo]

With a truss floor you can nail 2 rows of 1 by 4's to each truss (perpendicular to the trusses) to reduce vibration.
If you have a joist on frame type floor, vibration and deflection both are usually caused by not having enough piers under the home.