I’d like to hear from framers and/or builders who have significant experience with this product. Conjecture, one timers and reading the directions are things I already have… thanks anyway. They are the TJI 230s – the 9 1/2 x 2 5/16 I joists.
Directions say to use web stiffeners and squash blocks under load bearing walls but framer says that if the shop drawing for this floor system doesn’t specify them they are not needed. Inspector didn’t seem to care less one way or the other. I put them in after the framers left and used const adhesive to try to make sure I wasn’t creating squeaks. These 2 bearing walls have the perpendicular I-joists below and then triple 2×10 wood girders below the I joists (girders running parallel and exactly below the bearing walls) which in turn sit on masonry piers.
Thoughts?
Edited 8/19/2005 9:44 pm ET by Matt
Replies
If it belonged to me I would want it. Squash blocks are cheap insurance. GP web site suggests using material 1/16 taller than joist height. If you are referring to the mid point beam I would suggest making them large enough to bridge in between joists if it will not interfere with your mechanicals. then you get the 2 for 1. Bridge blocking(prevents joists from dominoing over), and serves as a squash block as well. I prefer lvl cut off scrap for my Sblocks.
You did Good! We squash block all point loads to the foundation. Will see if I can get some photos monday. Example would be a 3 member gider truss, 3 post in the wall when it hits the floor line 3 2xs next to the Tji bearing to the mud sill or foundation.
IIRC the packet that is stapled to the TJIs (which nobody reads) explains this .
G8 is right. Point loads should always be squash blocked on the TJI type joist construction. It's often one of those things that gets overlooked, even by the inspectors. You did the right thing.
Point loads should always be squash blocked on the TJI type joist construction.
Use web stiffeners or backer blocks for point loads. Squash blocks are for transferring loads between load-bearing walls. If there's no wall underneath, squash blocks don't make much sense....
Thanks guys. The framers did do the load points - anyplace where there were multiple jacks specified - but omitted some of the blocking at the interior bearing walls. They did blocking on one long wall because I tod them to. I added the web stiffeners and the slightly taller squash blocks in the other areas, but did not do any bridging, as this would have incurred a significant expense - plus I didn't have the material (~50 LF of extra I-joist), nor did I happen to have 50' of "scrap" LVL. :-)
You absolutely do need them.
I've done hundreds of I-joist layouts, and i've never once shown squash blocks on them. It's just assumed - Like the rim board.
Dang boss - you did wake up the roosters - didn't ya? Your in centeral time zone - right? And thanks for the info.
BTW - the max joist span is about 12' they are 9 1/2" x 2 5/16 I-joists. I'm hoping this will yeild a pretty stiff floor - thoughts?
Edited 8/20/2005 6:34 am ET by Matt
Well, my alarm goes off at 5am, but sometimes I can't sleep that late. I got up to check the weather, as I'm scheduled to work on a roof tearoff. But the rain's too close right now, so we're gonna hold off a while. Think I'll wander back to bed and see what DW is up to...(-:
After all, what is your hosts' purpose in having a party? Surely not for you to enjoy yourself; if that were their sole purpose, they'd have simply sent champagne and women over to your place by taxi. [P. J. O'Rourke]
You're fine with a 12' span on a 9.5" I joist. I think the max for live load is around 16'. When you reach the code limits for ####span though I always like to stiffen with solid bridging.
Boss, It's just assumed? I don"t know if that's a good idea. I get in trouble alot for not being specific enough.
How much detail to put on a layout is subjective, I guess. I don't think it's necessary to show every last detail. Where do you stop? Should you show the rim boards on the layut too? And if you show them, should you also show the nailing schedule? And maybe if I put that nailing schedule on the layout, the nailing schedule for fastening the things down should also be shown? Should I also try to figure out where the plumbing drops are? And why not show all the warnings that are in the jobsite bookets about not overloading the joists, etc. Like I said, where do ya stop?
Give me ambiguity or give me whatever.......
I wish I knew where to draw the line. All I know is how things aren't done on my jobs because I fail to be specific enough. I take it for granted people know the minor details.
Tsk, Tsk Boss, you seem to be getting that typical architect mentality.
We don't do many TJI jobs but we just finished the first deck on one today. I didn't see any generic jobsite truss booklet, but they did supply a detailed layout, which obviously was computer generated. It showed all the joist and it also showed the rim joists, header/beam locations and identified every hanger. All point loads were indicated and the required squash blocks were detailed in separate detailed 3d pictures.
All of this might seem like overkill and too much work for the office guys to do, but to me it's only the minimum. I will follow every detail on that sheet, to cover my azz, and to maintain high standards.
One thing that isn't detailed is squash blocks at the bearing walls. Since they aren't detailed on that sheet, I will not be putting them in.
Please direct me to some information that explains why I should over engineer a system that has already been engineered.
blue
edit: Since I don't have the second floor tji package, I don't know which wall are bearing.
Edited 8/26/2005 6:35 pm ET by blueeyeddevil
"I didn't see any generic jobsite truss booklet, but they did supply a detailed layout..."
If they decided to add all the details to the layout, you probably didn't need the booklet.
"Please direct me to some information that explains why I should over engineer a system that has already been engineered."
I never suggested that anyone should do anything like that. I have no clue what you're getting at.
Drugs cause amnesia...and other things I can't remember.
I'm confused Boss.
You (or someone else in this thread) is saying that all framers know that they should put squash blocks on the tjis under bearing walls (over the beam), yet my detailed plans don't show any. If I put them in anyways, I'd essentially be doing some seat of the pants engineering.
This is a case where ambiguous plans lead to mistakes. Either I'm mis-interpretting the plans, or the office guys have decided to indicate only some of the critical load points that require squash blocks. I've railed about poor truss plans and left out information and I hope this isn't one of those deals. I'll contibute some of my time (and dollars) and start the investigation process when I get back to work on Monday.
I wonder if I should be able to bill someone for my lost time spent doing the architectural planning and engineering. I'm getting paid only to do the carpentry and now I get to work for free because someone didn't want to press a button and add the information to the plans.
Yes, now I'm bitchin' about it.
blue
I'm still not clear on what you're ticked off about. If you have a detailed layout that shows where you need squash blocks, you know where to put them. If you DON'T have a detailed layout, but have the manufacturer's literature, you can easily figure it out. So what's the big deal?
Q. How can you tell that a blonde sent you a fax?
A. It has a stamp on it.
Boss, I'm confused because several posters have ascertained that squash blocks are required under bearing walls. Now, your saying that I don't have to unless the detailed plan shows them. You also mentioned earlier that some things are assumed.
My frustration doesn't occur when I'm dealing with dimension lumber.
Incidently, we've determined that it takes twice as long to frame a deck with TJI's.
blue
What brand of I-joists did you use?
If they were actually "TJIs" take a look at this web document, and specifically page 8:
http://www.trusjoist.com/PDFFiles/2025.pdf
Edited 8/28/2005 9:41 am ET by Matt
Matt, thanks for the link. Were using a generic version- not TJI's.
After perusing that link, I'm now more sure than ever that it's time for me to leave the carpentry field. All those charts and simpson hanger charts bore me to tears.
blue
I hear ya - that's why I gave you the page number. Hard copies of documents are good - much easier to flip through and find the relevant info. As far as all those tables, etc - more for designing - which in our case is already done. We just have to figure out how to properly apply the product to our particular project.
I agree Matt, I have a hard time seeing the numbers on my computer screen. I did take the time to look at every page in that document and that's when I remembered how much I hate paperwork!
Gimme some good old regular dimension lumber any day!
blue
Using these things for rafters, even framing a stairwell or skylight, seems like a royal PITA. All that f'ing around, adding little bits of this and that. Made my eyes glaze over too.
Pieere, we've determined that the TJI's will take us THREE TIMES LONGER than a dimensional deck. The timeframe has escalated dramatically because we have some cantilever situations.
Boss, we did end up putting blocking between every joist over the steel beam. When I got to work this morning and started studying and talking about the situation, the rookie pulled out the "carpenter's field book" that came with the load. He claimed that he took it home to read it (of course he didn't). After studying the details for an hour, I determined that we would indeed need blocking over the steel. Our shipping sheet claimed that we had about 50 of those precut blocks shipped, but of course they shipped a 40' long piece instead.
So, I was wrong about them not being needed on our job. The problem was that I just was not taking enough time to read and understand the details. Personally, I hope I never understand them.
blue
For whatever it's worth, my framer has framed dimensional, I-joist, and trussed floors for me, and undoubtedly a number of other builders. Based on your comments, I asked him what he prefers and what takes the longest. He said that they all take about the same but that he likes dimensional (2x10s) the best for their flexibility. He likes web truss joists the least because of the same reason - inflexibility - if they are built wrong or the foundation is off several inches you are hosed. He didn't seem to have real strong feelings about it though... may be partially because, in our market, all 3 types of floor systems are very popular so they see a lot of each. I say each type has it's place.
Just thought I would post a picture of a basic Squash- Block, in action for the viewers of this thread that are Framingly- Challenged.
Matt, some guys don't have strong feelings about spending inordinate amounts of times doing jobs. I get frustrated when it takes me 50 hours to frame an 18 hour deck.
blue
Squash blocks are a must. I've been doing I-joist floor systems for a long time and have never eliminated them. LVL's work great for this application.
Ocean State Builders,Inc.
Wilmington, NC
we did use some scrap LVL for point loads but there were roughly 100 squash blocks so I used 2x6 for these.
BTW - welcome - first time I've seen ya around here. I'm in Raleigh. Went to the beach for a short vaction this summer. Took a quick look at a few houses under construction - within a block of the ocean. I wanted to see the "costal construction" methods. There where not as many tie downs as I expected... I did see some nice flashing details at the sills though... soldered copper - not sure if it was custom made for the house (made to order) or if it was something that is a regular "in stock" kind of item. I gotta think they were not made on site unless they have a guy with a break who specializes in that kind of stuff - very neat work.
Oooo, there's a whole bunch a coastal vacation McMansions that are gonna blow away in the big one, if what I've seen is typical....Deck on deck, platform posted, w/no straps, ec., etc.
Matt ---
The carpenters get paid to follow the shop drawings. You should not be putting in extra materials.
The drawings should at least include the I-joist instalation directions as part of the details.
I always include the I-joist manufacturer's details as well as proper nailing schedules.
Are you saying that the squash blocks are not necessary, or just that the carpenters should not be expected to do anyting that is not on the shop drawing?
Most drawings do not include all those details because it is unnessecary. Th eIjoist come deliveered with a shjeet showing the details for installation that cleaarly show that the squash blocks are needed. Adding same details to drawings is wasteful redundancy. A single note, "install all engineered lumber to manufacturers specificatrions" is all that is needed on a drawing or in notes attachemnts
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
While I agree with your note, I would not trust any workman to correctly determine where squash blocks are required.It is not difficult for the engineer to mark a set of plans with squash block locations. I use a GREEN marker.Matt ---carpenters get paid to do what is on the plans not to do engineering. I believe that the location of squash blocks is an engineering decision.
In the case at hand, I will have to agree wioth you that it should have been marked out. Unfortunately, in this industry, too often The builder knows more engineering than the designer doing the drawing, so we have to know our stuff, or should I say, know your stuff.Anyway, as you can see from the other replies here, most framers in this venue do know that the squash blocks are needed.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Hi Piffen-
Sometimes it works the other way too. We had a case in my office a few years ago where a "carpenter" didn't put enough nails into a 2nd floor wood railing. Someone leaned against it and both it and they went down. Once the legalities started, the carpenter's defense was that the architect didn't have good enough drawings because he didn't show how to fasten the rails to the posts. Nobody could take the risk to see how that would fly with a jury - case settled, everybody paid money, including the architect.
How much detail is enough?
Don (formerly Hammerlaw)
Someone emailed me and asked me exactly what squash blocks were. Rather than reply directly I decided to post the info here so everyone could look it over.On the GP website, there's a 2 meg PDF file with a lot of their installation details at: http://www.gp.com/build/DocumentViewer.aspx?repository=BP&elementid=4372Page 22, block F10 shows the most common squash block detail - One load bearing wall stacked over another. There are also a couple of other details; Page 22 block F4, and page 25 Block F19. But they're not used as often. Just thought this might clear up some confusion, in case there were some who weren't certain what they were or what they were used for.
Strong women leave big hickies [Madonna]
The instructions for installing squash blocks show nails going horizontally into the flanges (8d for GP, 10d box for Trusjoist). I just wanna add a note of caution about going any bigger, since I didn't see any warning in the docs. I had to take out joists installed by carpenter, because he put 16d nails into the flanges and the joist manufacturer said the joists were toast as a result.
Kinda like shooting that rabbit with the .50 cal instead of .22 eh?
That's a good heads up Taylor!
blue
>Unfortunately, in this industry, too often The builder knows more engineering than the designer doing the drawing, so we have to know our stuff, or should I say, know your stuff.<Can I hear an amen somebody?!!Very well said Notchman
"... too often The builder knows more engineering than the designer doing the drawing"
You know, I could take offence at that. (-:
I often meet builders who THINK they know more about design and engineering than I do. But I haven't met one for over 15 years that did.
So while you may be correct in some cases, I think that's gross over-generalization.
Never fight ugly people - They have nothing to loose.
If it happens once, it is too often, right?Don't take offense because you do yours right, but I have never seen a set of plans I didn't have to call out for corrections on.
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
I agree with you GHR. I don't put extra lumber in. One of the main reasons to use engineered lumber is to save resources and labor. I find it redundant and wasteful to add dimension lumber if it isn't needed.
Save the owls.
blue
It's good of you to include those I-joist details in your drawings, but any professional builder using I-joists should be following the installation inst. that always comes with the joists.
But, I suppose it's as you say, one can't assume too much.
But where do you stop? Do you also include the bracing schedule for trusses? All the fireblocking details? Identification of all airtight ceiling lights? Diagonal dimensions on foundations? The R/O's of windows and doors in addition to the window /door schedules? The screw/nail schedule for sheetrock? The taping of vapor barriers? Window flashings?
EVERY G/C and/or site foreman should have a current codebook handy and be familiar with it. They should also be familiar with the peculiarities of the materials they're working with.
If the builder is a DYI HO, then, I suppose, a lot of detailed instruction may be necessary.
But, to me, the critical info on a plan set are those details site-specific to the project, like rebar schedules, siesmic hold downs, strapping, shearwalls, etc., that fall outrside of code requirements, or standard building practices.
Well said!
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This thread started with a complaint that carpenters did not know where to install squash blocks. I doubt that those carpenters should be trusted to make engineering decisions.Any feature that I engineer is completely detailed. The carpenters are expected to read the details and follow them.
I agree that carpenters should not be required to make engineering decisions. On the other hand, knowing where the bearing walls are in a house is not an engineering decision. As a matter of fact, one long wall going down through the center of the house was labeled "bearing wall" right on the house plans. Reading the directions is not engineering work either...
The shop drawing was 1 page. The only reference it had to squash blocks was under "NAILING REQUIREMENTS" and says: "2x4 minimum squash blocks Two 10d (3") box nails, each at top and bottom flanges." In the plastic envelope that came with the package was the shop drawing and 2 sets of generic instructions, plus 2 "pocket reference" books were stapled 1 each to a couple of the I-joists. All these instructions and booklets covered the installation of squash blocks and other details.
So, although this house was engineered, every detail was not addressed. This is normal. The reality of it is that we use design professionals (eng & archi) to do the complicated stuff like figure load points, etc, etc, etc (I'm talking residential frame construction here). Plans must be stamped to get a permit. It is the builder's and carpenters jobs to make it all work. I addition, the engineering firm we use has an engineer on call who is readily available for questions - during their working hours. That works out nicely.
As a point of clarification though, just as the builder/carpenter should not be making engineering decisions, in most cases, an eng/archi is not a builder/carpenter either and should not fool himself into thinking he is. :-)