Replies

1. 
   Griz | Mar 01, 2005 08:14pm | #1

   Greetings,

   In my neck of the woods a web stiffener is used on engineered wood "I" beams, (TJI etc) as required by mfg.  Squash blocks or crush blocks are nailed to side of the bottom chord of a truss where it fastens to the top plate.

2. 
   BruceM16 | Mar 01, 2005 08:38pm | #2

   The 'Framers Pocket Guide' that comes with each batch of TJI's is really the source document that will help you with this. But in case you haven't yet gotten your batch.....

   A 'squash block' is designed to transfer the downward load of a weight bearing wall above the TJI, to the wall below. Seems the wooden I-Beams are not designed for compression, but for tension. just make sure the squash block sits proud of the top of the TJI by 1/16" or so....my inspector laid a straight 2X4 across the top of all of them then eye-balled to make sure all tops were above the plane of the top of the TJI's.

   Web stiffeners are simply used in the web of a TJI as it goes over a wall below but where there is not a weight bearing wall above.

   You can download the pocket guide as a .pdf file at

   http://www.trusjoist.com/PDFFiles/2030.pdf

   BruceM

1. 
   bhackford | Mar 01, 2005 09:04pm | #3

   So all ends of I-joist need squask blocks?  Do even gable walls where there is no roof load?

1. 
   BruceM16 | Mar 01, 2005 09:19pm | #4

   No...only under weight bearing or sheer walls.

   Take a look at the diagram in the framer's pocket guide

1. 
   bhackford | Mar 01, 2005 09:29pm | #5

   So all weight bearing walls need squash blocks to transfer the load.  And you need squash blocks on both sides?  Wouldn't these hold the plywood subfloor up 1/16?  And on the gable ends no squash blocks needed so down 1/16?  Will OSB rim hold up non-load gable end walls?

3. 
   BossHog | Mar 01, 2005 09:33pm | #6

   In general, web stiffeners are used when you need to fill out the plywood web flush with the top and/or bottom flange of the I-joist.

   Squash blocks are used where an I-joist crosses an interior wall where there is also a bearing wall ABOVE it.

   The exact terminology and specific details vary from one manufacturer to the next. The place where you buy I-joists from should have an installation/design guide that give their requirements.

   Here's a link to GPs web page. There are lots of documents there that can be downloaded:

   http://www.gp.com/build/product.aspx?pid=1390

   Because modeling is lucrative, I'm able to save up and be more particular about the acting roles I take. [Kathy Ireland, star of Alien from L.A. and Danger Island]
1. 
   FramerT | Mar 02, 2005 02:05am | #7

   You get an inspection before the ply is laid? Have put web stiffeners in when using only TJIs on gable ends,over bearing walls although inspecter says squash blks. are OK, when TJIs will have hangers on them,etc. As mentioned, read the info.
   Most of our plans have an joist diagram,saying where they want point loads,joist/rim board combo,etc.
   I didn't do it....the buck does NOT stop here.

1. 
   Sphere | Mar 02, 2005 02:56am | #8

   Don't squash blocks also need to be grain oriented?...like vertically? 

   Spheramid Enterprises Architectural Woodworks

   Restoring, Remodeling, Reclaiming The Quality..

1. 
   gdavis62 | Mar 02, 2005 03:10am | #9

   Absolutely.  Otherwise they might be called "swell" or "shrink" blocks.

1. 
   FramerT | Mar 02, 2005 03:30am | #10

   2x4s nailed vertically= squash blks.Am afraid I missed your point.
   I didn't do it....the buck does NOT stop here.

2. 
   bhackford | Mar 02, 2005 04:38am | #12

   So, I need 2 squash blocks on every floor joist /rim junction? 2X10s may have been easier. GP sells a new "stiff rim joist" that you don't need any squash blocks for? Thanks

3. 
   gdavis62 | Mar 02, 2005 05:34am | #13

   Please, read that stuff that came with your I-joists, or download the how-to info from the TrusJoist site.

   Squash blocks are typically only needed at concentrated load points.  They are not needed at span ends where the rim is picking up load.

   Were your floor frames engineered by the I-joist supplier?  Most all jobs using them are done this way, and the prints always call out the location of squash blocks.  That's how Tim's inspector knows where to look for them.

   Was your job not engineered as described?  Are you simply substituting them for sawn lumber framing, and laying things out where you like?

4. 
   bhackford | Mar 02, 2005 05:49am | #14

   No, they are going to be laid out by a truss company. I just wanted to get a big jump on the cut list. So, I am try to understand more of the rules than are probably needed. I could just wait and follow the instructions.

5. 
   gdavis62 | Mar 02, 2005 05:58am | #15

   Here ya go.  http://www.trusjoist.com/PDFFiles/2030.pdf

   Why wait?  Print it out, and now you have some bedtime reading.

   Detail CS on p. 9 and B2 on p. 10 show the crushers. 

   Enjoy!

6. 
   concretedetail | Mar 02, 2005 06:05am | #16

   I beam joists can save a lot of time running joists on a floor system because of extended lengths, less weight, etc. and this is often touted as a time (labor=$) saver, but I'll tell you, by the time you install all the web stiffeners and squash blocks specced out on the engineered plan, you don't save much! It's tedious work.

   But I do think you end up with a superior floor deck, if designed properly. Glad you are not winging this without the plan.

7. 
   BossHog | Mar 02, 2005 04:21pm | #17

   "So, I need 2 squash blocks on every floor joist /rim junction? "

   I've never seen an I-joist manufacturer that required that. The typical 1" thick rim board is good for something like 2,000 PLF. That's plenty for most any residential situation. (Although local codes could require just about anything)

   Squash blocks are used at INTERIOR bearing walls. And only if there's another bearing wall stacked ABOVE the I-joists.

   If you're getting these from a truss company, I'd be very surprised if they wouldn't give you an installation guide if you asked.
   I can do anything you want me to do so long as I don't have to speak. [Linda Evangelista]

8. 
   bhackford | Mar 02, 2005 08:56pm | #18

   Thanks, that is what I thought.  The 1 1/8 rim has to be good for something.    I will ask for the installation guide just so I am not reading and then building....not fun.

2. 
   Timuhler | Mar 02, 2005 04:00am | #11

   Tiz,

   We have to have an "under floor" inspection before we lay any subfloor.  Can be a huge pain. 

   The inspector in the city limits told us if he's not there, go ahead and start sheathing.  County is a different animal.

4. 
   panelguy | Mar 02, 2005 09:05pm | #19

   Generally speaking, web stiffeners are provided to give the TJI some meat to nail into (e.g. hanger, blocking, etc).  Squash blocks carry a point load.  Both of these are used in an engineered wood-I floor system.