Replies

1. 
   calvin | Feb 11, 2011 06:41am | #1

   ed

   It's not necessary to stack frame, however-start your layout of wall studs and joists from the same place and double the plates.

2. 
   glacierfergus | Feb 11, 2011 12:16pm | #2

   I asked the same question to one of the top builders in my area and his response was the same as Calvin's.  He did mention that if you have a heavy point load (such as where the king and jack land for a 10 foot window) that it would be a good idea to put some blocking in at that point.  Probably not essential, but a good idea.

1. 
   calvin | Feb 11, 2011 01:05pm | #3

   Thanks for including that tip...........

   A point load like you mention, and moreso for a beam support, is not considered supported until taken down to the foundation.  Normal thinking (I would hope) for a remodel, but sometimes missed in new construction.  Inspectors quite often see this in framing which includes a ridge beam. 

   Good of you to mention it.

3. 
   xxPaulCPxx | Feb 11, 2011 01:24pm | #4

   I would ask why the floor couldn't be done on 24" centers with thicker material - this would allow more insulation and less thermal bridging through the floors, in addition to the constant load path to the ground.

   I ask because I'm ignorant on this point - can a floor 24" OC be not bouncy?

1. 
   MrEd72 | Feb 11, 2011 10:12pm | #6

   Response to WHY NOT 24" OC?

   This is a 28' x 42' garage with a second story room, therefore the 28' floor trusses. 16" OC is what was called for from the truss manufacturer. They are already 19" deep and I would hate to see how much bigger if we went with 24" OC. I too would be nervous of too much bounce in the floor at 24". Insulation and thermal bridging are not an issue here because both first and second floor will be conditioned spaces. This will be our temporary residence during the demolition of an old farm house and subsequent new home construction.

4. 
   BossHog | Feb 11, 2011 07:39pm | #5

   It bothers me when people mention long span floor trusses and 16" O.C.  Often they're putting them closer together to try to keep the depth down. That sounds good on paper, but in reality an make the length over depth ration high enough that the floor has vibration problems.

   Quite a while back I did a thread on floor viration. If you'll have a look at it you'll see what I'm getting at.

   http://forums.finehomebuilding.com/breaktime/general-discussion/floor-vibration

1. 
   MrEd72 | Feb 11, 2011 10:18pm | #7

   Thank you for the link. I will research this a little more, and may compromize on going a little taller on the truss.

5. 
   DoRight | Feb 15, 2011 03:20pm | #8

   What is the pitch and snow load?

   I am looking at a similar roof situation and ahve not talked to a truss company yet.  I am curious as to your roof pitch and what live / snow load you are building too. Thanks.

6. 
   DaveRicheson | Feb 16, 2011 06:12am | #9

   Truss depth.

   I would agree with Boss on the depth issue. He is the expert.

   Increaseing the size to 20 or 22 inches and changing the spacing to 19.2" on center will likely get you the stiffeness you need and reduce any vibration significantly. With floor trusses you have a 3 1/2" wide top cord, so the actual distance betweent the truss members is 15 1/2" when you use  the 19.2" o.c. spacing. With 3/4" Advantec subfloor you still meet the deflectometer guide lines for ceramic tile installation.

   The increased truss depth and increased spacing placement almost offset each other in terms of cost.

   What are you setting the trusses on?  Frame wall, block wall, or poured concrete wall? What the trusses are setting on is as important as what is setting on them.

7. 
   Geoffrey | Feb 19, 2011 12:37am | #10

   Ed,

   code requires that you double your top plate when you are not "stacking" your studs and floor joist

   Can I still incorporate 24" OC wall framing or should I keep the trusses centered over the studs?

   Wasn't this info given to the truss designers before they designed the floor trusses??

   Geoff