I just re-read the section in FHB168 on trusses. Could you give me some other tips for easy install that did not make the article? I will appreciate all input and thoughts. I am doing a big truss job in May. Thanks
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Greetings BHACKFORD,
That subject has been addressed here on Breaktime a number of different times in the past.
If you scroll down in the lower left corner of your screen there is a search function that will take you to previous threads dealing with whatever you type in the search bar.
If you type in 'trusses' or other keywords of the subject matter you'll get a good supply of data from those old threads.
If needed, reposting a specifically directed question might be more fruitful instead of a wide sweeping general request.
Cheers
REZ!!!!... it's the upper left...
proud member of the FOR/FOS club...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Fine.
You tell the poster then.
Lower left is.......
.........EZer.
be easy
so now yur easy...
shall I pass that on to the purple gang...
awww what's the difference.... they got the link and seem to be addicted...
proud member of the FOR/FOS club...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
I have always used the advanced search in the upper left too. I just now learned that there is a simple search in the lazy left corner pocket
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
BTW, If youstill have earthlink addy, I emailed you there
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
still got it and I have laptop wireless too now...
Cheyanne is an hour south of me now...
I found Colorado 'cause they weren't fast enough hiding it on me...
proud member of the FOR/FOS club...
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Get a box of the steel spacers, they are the perfect length for truss spacing at 24 inches. They just hammer down in place add a few nails and you are not out on a ladder with your tape measure sticking out trying to make sure your trusses are spaced correctly. I also mark the sheets of plywood at 2 foot centres so I make sure the mark is centred on the truss as we sheet up the roof. Trusses can go a little crooked between the time they are built and the time you install them. You probably measure the top chord so you don't end up with a strip[ of plywood across the top less than 16 inches.
Have a good day
Cliify
we mark our strapping with the centers..... and pre-start our nails to set our temporary bracing as we spread the trussesMike Smith Rhode Island : Design / Build / Repair / Restore
What kind of trusses? Residential, or big (comercial) stuff?
Bracing is #1 on my list of suggestions. I've had the misfortune to wade through several jobs where the trusses had fallen over due to inadequate bracing. (More on that later)
I don't recommend the metal spacers that were mentioned earlier. More than half the broken piles of trusses I waded through had these metal spacers on them. These things are NOT to be used as bracing. But all too often they're the only thing holding the trusses up.
.
But on to other stuff. I can't imagine anyone wanting to set trusses without a crane. Some guys use a crane to lay them on the walls in bundles, then stand them up later. Others set them by hand or use a rough terrrain forlkift of some sort.
But I want the crane there to set every one of those things right where it goes. It seems much safer to me, and is well worth the expense.
.
Assuming you're going to set them with a crane, try to get a crane operator who's set trusses before. That way they will likely have the right equipment anda sense of what's going on. Some truss companies offer crane service, others don't.
Get the truss layout ahead of time and figure out where the crane will have to sit. Start setting the trusses furthest away first and work towards the crane. That give te crane guy a better line of sight so he can see what he's setting more easily.
.
Here's a link to the "official" truss bracing sheet:
http://www.tpinst.org/Color%20HIB%2091%20Sheet_v3.pdf
.
And here are some links to threads about bracing and truss collapses:
http://forums.taunton.com/n/mb/message.asp?webtag=tp-breaktime&msg=34525.1
http://forums.taunton.com/n/mb/message.asp?webtag=tp-breaktime&msg=29923.1
http://forums.taunton.com/n/mb/message.asp?webtag=tp-breaktime&msg=27573.1
Did you ever research the Simpson product? If not you might be advised to look at them, they appear to be a different animal from the little spacers most are familiar with.
http://www.strongtie.com/products/connectors/TSB_PT.html
There are 3 companies I know of that make spacers like that, which can function as bracing. Trouble is, they're expensive - Roughly double the price of The 10' foldout sections. So they've never caught on around here.
Blessed are the meek, for they make great scapegoats.
Is the 10' foldout the "Trusslok" product? Is it worth the money?
I honestly don't know the brand name of the ones we sell. I think there are a couple of different companies making them. Are they worth it? That's probably a loaded question. Right up there with "Should I vent my attic?"(-:I think they're ridiculously expensive - A heck of a lot more than a 2X4 the same length. If you use a 2X4 as a brace, you can take it off and use it for something else. But the truss spacers aren't reuseable.So to me they're a huge waste of money. But others claim they save so much labor they're worth it. But they really don't save labor if you use them correctly. (ie: Follow up with bracing)At least that's my opinion...
Q: Why do bagpipers walk as they play?
A: To get away from the sound.
We have the Trusslock and it really speeds up rolling trusses. But they should only be part of the bracing as you go. For smaller trusses, they can't be beat.
But I want the crane there to set every one of those things right where it goes. It seems much safer to me, and is well worth the expense."
Boss,
Yeah, I agree,
but the GC who built my garage still managed to get them in place the old fashioned way (twentytwo 26' span attic trusses) using 4 young bucks and poles. Then again....he didn't plan for a way for me to get up to that attic, LOL I guess he just pocketed the $200 crane charge.
.Jon
I only use the spacers as spacers, to ease the installation. Of course I follow the engineers instructions exactly for the required bracing.
Have a good day
Cliffy
Thanks. This is info is great. With regard to installing valley trusses, any special tricks? What is the best way to lay these out? Thanks again,
I don't personally like valley trusses, as I don't think they're cost effective. And I've never actually helped install them. But a couple things still come to mind. Some truss plants lay them out from the peak down. Others ltry to continue the layout of the trusses that the valley is based on. Asking the truss company what they've done might help you get lined out.I've heard the best way to set them is to run a string line for the peak. Then slide the trusses up or down the slope until they touch the string. Maybe some of the other guys will ahve some input...
A great many people think they are thinking when they are merely rearranging their prejudices. [William James]
It would seem that they are not cost effective but the cost without them is a very very small diffence and I do not think I stick it for less. So, i am buying valley trusses. The string was what I was think of but I was not sure if there was a faster method. Thanks again.
I put the plywood on the main roof first, then put the valley set on top. Makes life much easier.
Have a good day
Cliffy
Ditto here. Main roof plywooded then a simple lay-on or truss set.
I didn't do it....the buck does NOT stop here.
"I put the plywood on the main roof first, then put the valley set on top. "
Actually, that's what you're supposed to do. The plywood is needed to brace the top chords of the trusses under the valley.
A journey of a thousand miles begins with a cash advance.
Since both sections of the attic are closed then do you need to install two hatches for attic access? Or can you cut a hole in the plywood under the valley so you can access both sections?
Bhackford, around here, either way will work. Normally, we cut out a large access in the underlying sheathing...enough for the fireguys to climb through if they desire. Also, one locality insisted on the opening to facilitate the free flow of air which ventilate the deck. In that locality, you would be required to cut out a section of sheathing even if you added the second access.
blueJust because you can, doesn't mean you should!
Warning! Be cautious when taking any framing advice from me. There are some in here who think I'm a hackmeister...they might be right! Of course, they might be wrong too!
So sheath the roof then go back and cut out a hole or cut off all the sheathing under the valley? Thanks for your help
We usually just leave a hole as we are laying, but quite often we cut one in. Keep in mind that we do all our cutting in place, up there on the roof, so out saw is always handy.
blueJust because you can, doesn't mean you should!
Warning! Be cautious when taking any framing advice from me. There are some in here who think I'm a hackmeister...they might be right! Of course, they might be wrong too!
"Since both sections of the attic are closed then do you need to install two hatches for attic access?"
Guess that would depend on local codes. Personally, I'd want a way to get into both attic areas.
Creativity is great, but plagiarism is faster.
Unless you are puttting P.Eng after your name you can only suggest you are supposed to put the valley kit after the plywood is down on the mani roof. I suggested doing this way because I've done it both ways and it certainly is more convenient. However I have had this discussion with the technical representative (that is their engineer) and he told me that the valley truss kit could be nailed on the main roof first if I wanted to save some plywood, the valley kit at their 24inch centres act as the bracing. Similar to installing a steel roof on strapping on trusses.
Have a good day
Cliffy
"Unless you are puttting P.Eng after your name you can only suggest you are supposed to put the valley kit after the plywood is down on the mani roof."
I've been trying to decide whether you meant that to come across as being a smart a$$ed comment or not. Can't really tell.
But what I said wasn't my opinion, it's the industry standard.
Trusses are designed with the assumption that the top chords are continuously braced, or sheathed. That's why plywood is required under valleys - The top chords of the trusses under them still have to be braced.
Whomever told you that nailing the valley to the trusses was O.K. most likely wasn't an engineer, or simply didn't know what they were talking about.
I poured Spot remover on my dog. Now he's gone.
Boss, there aren't a whole lot of framers that understand that the trusses need to be braced on their top chords to meet the engineers standards.
Sadly, very few framers have taken the time to read and understand basic truss installation guidelines. The incredible thing about that statement is that we get a new package with the guidelines in every set of trusses. They just toss them on the ground without reading them!
blueJust because you can, doesn't mean you should!
Warning! Be cautious when taking any framing advice from me. There are some in here who think I'm a hackmeister...they might be right! Of course, they might be wrong too!
I used to brace trusses wherever the diagram showed them.Inspecter man would flunk you if your brace was on the wrong side of a chord. If the diagram showed 4 2x4s bracing under the piggy-back,you'd better put 4 there.
I didn't do it....the buck does NOT stop here.
The inspector man was wrong. The permanent lacers can be placed on either side of the chords.
blueJust because you can, doesn't mean you should!
Warning! Be cautious when taking any framing advice from me. There are some in here who think I'm a hackmeister...they might be right! Of course, they might be wrong too!
"...very few framers have taken the time to read and understand basic truss installation guidelines. ...we get a new package with the guidelines in every set of trusses. They just toss them on the ground without reading them!"
I would hope you'd toss them in a trash can, not on the ground. Those packet of literature are also useful for starting a fire to burn your scrap lumber. (-:
Many truss companies send those packets out to protect themselves from liability. They don't really care if you read them or not. The fact that they send them out on EVERY load means a great deal to the lawyers.
Too bad it can't be condensed down to practical information that guys in the field might actually read. I know I sure wouldn't want to wade through all the B.S. we send out.
Yesterday I was arrested for scalping low numbers at the deli. I sold a #3 for 20 bucks.
Too bad it can't be condensed down to practical information that guys in the field might actually read. I know I sure wouldn't want to wade through all the B.S. we send out
It might be a boring read, but don't you think that since it's their livelihood and their lives at stake, that they'd at least read it once?
blue Just because you can, doesn't mean you should!
Warning! Be cautious when taking any framing advice from me. There are some in here who think I'm a hackmeister...they might be right! Of course, they might be wrong too!
"It might be a boring read, but don't you think that since it's their livelihood and their lives at stake, that they'd at least read it once?"
Not really. Most guys entering the trades are younger, and still think they're "bulletproof".
Besides - Real men don't NEED instructions. Reading paperwork wastes time, and is a sign of weakness.
Not saying the above is right, just that it appears to be the norm.
It seems to me that if you could re-write the stuff to make it plainer and simpler, it would be more likely to get read. But when you keep running into stuff like :
WARNING! Sticking your tongue in a light socket can cause electrocution
WARNING! Beating yourself in the head with a hammer can cause personal injury
WARNING! Shooting yourself in the eye with a nail gun can cause injury or death
You get the idea. No one likes reading that insulting crap. If you could have the stuff written by a NORMAL person instead of a lawyer it might actually be readable.
There is an inverse relationship between reliance on the state and self-reliance. [William F. Buckley, Jr.]
Man, you guys keep this up and you'll be written down as the greatest comeback thread in all of BT history.
be archived"Live Free, not Die"
We actually have had a 'dumbed up' version of truss plans before. It had neon green stickers on every truss in every single spot they wanted a brace. Each one said "BRACE HERE". It was actually pretty funny to see how many stickers were in this roof. I do agree with the statement about us young guys not reading the lit. sometimes. I got caught once I had one truss with a pointload in it and totally missed it. The engineer said I would have to strap both sides of the truss with 3/4 inch ply and nail it 8 inches o.c. with 6 inch nails double cinched. Of course the truss was in the most difficult place in the house. Atleast I had a palm nailer. I LEARNED!!! The hard way. Is there really any other way?
" I got caught once I had one truss with a pointload in it and totally missed it."
I don't consider this your fault at all. This is one of my pet peeves.
Any truss designer with his salt should make girders "idiot proof". That's not to say that framers are idiots - Just that anything that CAN go wrong WILL go wrong.
Every girder design that I send out is reversible, so it doesn't matter which way it gets installed. (IF the girder is symmetrical)
If the girder can only be installed one way, the truss company should have clearly communicated that to you.
Why do stores put in 25 check-out lanes, and then only open two?
Boss, I always thought the girders should be reversible, where possible. I've noticed that when they aren't, somewere they do mention that they are NOT reversilbe. Great...now if they'll tell me which is the front and which is the back, I'll really be happy!
I guess you could say that my pet peeve is this...they don't orientate all the pictures the same on the spec sheets.
blueJust because you can, doesn't mean you should!
Warning! Be cautious when taking any framing advice from me. There are some in here who think I'm a hackmeister...they might be right! Of course, they might be wrong too!
You know what was actually sick about this. It was a power horny inspector, the point load only actually missed by about 10 inches. Not to mention the load was small, the span was under 12 feet. I had never had that problem before. I guess normally the trusses I use are some what fool proof.
A 3ply girder truss, anyone have to put 1/2 inch steel plate underneath to 'distribute' the load? Of course that meant no way to nail the girder still. Or Inspecter Fife says "you need to put these Simpson bearing enhancers on the girder"...to distribute the load. Yet build the same house 10 miles over in the next county, they've never heard of it. Blue, if the brace was nailed on the proper chord[per diagram] but wrong side of the 2x4 chord, I've had to go back. Failed:bracing not to spec's.
I didn't do it....the buck does NOT stop here.
FramerT, I would have had the engineer send a letter explaining to the inspector the way it really is. The computers are indicating the center of the compression strut and it doesn't matter which side. I don't care what that inspecter thinks, I only care what the engineer thinks and I know what he thinks, because I specifically asked him about that detail.
I've also had to install the steel plates under the three or four ply girders. Of course there aren't any nails fastening the girder to the wall, but really, I think the total weight and gravity will do a fairly good job of keeping it there.
I've also had to install those goofy weight distributors in lieu of the steel plates. It all depends on the engineers, some of which I'd like to take out back...
blueJust because you can, doesn't mean you should!
Warning! Be cautious when taking any framing advice from me. There are some in here who think I'm a hackmeister...they might be right! Of course, they might be wrong too!
"A 3ply girder truss, anyone have to put 1/2 inch steel plate underneath to 'distribute' the load?"
Girder bearing area is getting to be more and more of a problem, it seems. Houses are getting bigger, so truss and girder spans are getting bigger. Having a girder truss with a 10,000# reaction isn't at all unusual anymore. The biggest one I've personally dealt with had a reaction around 25,000#.
The reason that this is a problem is because of the potential to crush the wood where the girder truss sits on the wall. SYP lumber can handle roughly 565 PSI of pressure. So that means one ply of a girder truss can handle roughly a 3,000 reaction (on a 2X4 wall) before you're over the limits.
There are several ways I've seen this dealt with:
Bearing enhancers like Simpsons: http://www.strongtie.com/products/connectors/tbe_pt.html They add about 2,000# of capacity to the bearing of a truss by supporting part of the load. But they also require you to drive a BUNCH of nails through the heel of the girder truss, right where the nail plate is.
Bearing blocks. These are short pieces of lumber attached to one or both sides of the girder to distribute the load over a wider area. This works particularly well if there is a vertical member in the truss directly over the bearing.
A steel post with a welded saddle. This obviously wouldn't work well in a house wall. But many of these situations happen in garages where part of the 2nd story is over the garage and is carried by a girder truss. So a metal post in a garage wall isn't quite as big of a deal.
Ignoring it. This is probably the most common. (At least around here) Truss companies don't really worry about it, and neither do the contractors. (Up to a point)
Personally, I don't worry about until the girder is at least 1,000# over the limit. I don't figure the whole roof will ever be loaded to it's full design load. And I've never heard of a serious problem caused by inadequate girder bearing.
And if my engineer reads this, I'm probably in deep stuff..........(-:
A conclusion is the place where you got tired of thinking.
Boss, amazingly, I've experienced every one of your situations! My preference is the ignoring one but alas, that decision isn't ours to make.
blueJust because you can, doesn't mean you should!
Warning! Be cautious when taking any framing advice from me. There are some in here who think I'm a hackmeister...they might be right! Of course, they might be wrong too!
Bhackford, check out message #53440.38.
See if those pics are correct.
Thought I'd bump this up for ya.
Yes, I did re-read this, and now I do remember starting this post but today's question is what is the fastest way to get the valleys layed out? String from above and space 24 on the bottoms? Or is there a faster method?
Had to make sure we were talking about the same thing before I answered.That jpg. is what I had meant as a 'lay-over'.
The P. Eng reference was not meant to be a smart assed comment, that is not my style. However the comment that the valley set acts as bracing seemed sensible to me from the rep I deal with. He has been in the business over 20 years and I have used his product often. As far as him being an engineer I'm not sure but I will be checking as I have two homes on my plate right now that will be going up this spring and I will be sending him the business.
As far as the industry standard being plywood down first, I believe you that it is in your area. I'm in Canada and we have many different practices that are approved for use here. Two other examples in regards to trusses are, the ridge blocking I see being discussed and the blocking at the top of the wall. I've never seen either done here.
Also the quote from your truss document "the supporting trusses should be designed either for the application of sheathing or purlin spacing from the bottom chord of the valley set frames". I find it a little confusing but do they mean purlins in additon to the bottom chord of the valley set or that the bottom chord of the valley set can be designed as the purlin?
respectfully submitted
and have a great day.
Cliffy
"the supporting trusses should be designed either for the application of sheathing or purlin spacing from the bottom chord of the valley set frames"
I can see how this could be confusing. Let me take a shot at explaining it.
Typically trusses are designed with the assumption that the top chord is continually braced, or sheathed. That assumption would mean that the trusses beneath a valley would have to have plywood on them.
But let's say you told your truss company that you did NOT want to put plywood on those trusses, but instead wanted to use the bottom chords of valley trusses as purlins.
This would mean that the trusses under the valley would have to be DESIGNED for purlins on the top chord.
For instance - Assume the trusses under the valley are a 5/12 pitch, and the valley trusses are 24" O.C. This would mean that the "braces" on the top chord of the trusses are 26" apart. (measured along the rake.
This may or may not alter the design of the trusses. (Wider purlin spacing means less strength)
If they are fairly short span and not heavily loaded, they may work fine. But take a heavily loaded, maxed out scissor truss with a lot of compression in the top chord, and the design will probably no longer work.
Your truss designer would have to alter the design of the trusses to make the purlin spacing fly. That may make the trusses more expensive.
If that doesn't make sense, I'll take another shot at it.
Last night I was in the mood to see something silly and idiotic on TV. So I put the cat there.
I get ya.
The house in paricular when Kirby (my truss guy) told me to go without plywood was actually my own house in 95. The valley set is very small. If I was as computer savy as you I could post you a picture! One of these days I'll figure it out.
Any way after doing my own hous that way to save only a few sheets of plywood it seemed like a crazy pain in the rear to do it that way.
Have a good day
Cliffy
P.S. When I figure that scanning business out I'll post a photo I have of me with Sorrel Brook from The Dukes!
Just in case what I posted earlier wasn't good enough for ya, here's more.The attached screen capture is taken from page 48 of BSCI 1-03, published by the Wood Truss Council of America and the Truss plate Institute. (Page 61 in the PDF version below)You can download a copy here if you like:http://www.woodtruss.com/projects/woodtruss/images/publication_images/bcsi103.pdf?PHPSESSID=626b0192006bab7856eff9bc9e6ce16f
National Atheist's Day April 1
Boss, Ive worked with trusses for about 30 years now and I've never seen or heard of a valley truss.
What is a valley truss?
blueJust because you can, doesn't mean you should!
Warning! Be cautious when taking any framing advice from me. There are some in here who think I'm a hackmeister...they might be right! Of course, they might be wrong too!
"What is a valley truss?"
Tell ya what - Let me get back to work tomorrow morning, and I'll try to post some pics.
But basically it's a set of "filler" trusses that are used where 2 perpendicular roofs interstect.
Paying alimony is like feeding hay to a dead horse.
Awright Boss...I think I know what they are now. Thanks for the explanation.
I'll regurgitate it.
The valley trusses are the trusses that are used to do "Califonia Fills" or whatever they're called out west. We call them layons.
You post to Bhackford about having to sheath under the valley trusses gave me the clue that I needed to understand. Normally I sheath fully under the layons because the specs call for the sheathing to do the lateral bracing of the top chord, but our specs always allow us to substitue 1x4 lacing 24" oc. I rarely substitute that, but I do remember substituting it once on a large commercial application. The layons were quite substantial and the 1x4 lacing was much more efficient in terms of materials and time to install, and it was also handy to use it as a ladder to climb the large roof.
Edit: I do remember having valley shipped out on a couple of jobs over the years. I'm fairly certain that we tossed the pile out the second time they were shipped because we screwed when using them for the first time. YOu know how it is....old habits die hard....I think the third time they were shipped, we figured out how/what to do with them.
I haven't seen them since.
blue
Just because you can, doesn't mean you should!
Warning! Be cautious when taking any framing advice from me. There are some in here who think I'm a hackmeister...they might be right! Of course, they might be wrong too!
Edited 2/8/2005 9:27 pm ET by blue_eyed_devil
another nice thing with a trussed roof is that if it's steep (out here it's usually at least eight, lateley ten and up seems to be the norm.)You can use your continuous bracing to stand on while you sheet the roof. This way you never really have to go outside of the roof. Some safety inspectors may not like this practice however so do be warned. Technically if were tied to the roof there are supposed to be engineered points at which we can tie. Such a thing doesn't exist in our roofs. Usually I prefer to go sans rope. One of my partners prefers to use a fall restraint system seems to work well for him.
Obviously you've figured out what a valley truss but here are a couple of pictures just in case it wasn't clear to someone else out there.The picture called "Valley 1" shows a house with a set of valley trusses on it. The red arrow points towards the valley. In the one called "Valley 2" I removed the trusses beneath the valley so the valley trusses could be seen more clearly. You'll notice in the pictures all the lumber is clear SYP - No knots or wane.(-:
You never really learn to swear until you learn to drive.
Boss,
What kind of software are you running? That's impressive, showing the plates like that.
The software is just our regular truss design software. http://www.alpeng.com/The 3D stuff is occasionally useful, but not terribly functional. Mainly it's there to impress the owners - The ones who buy the software. The guys like me that USE the software don't really care about the fancy stuff - We want more functionality.
I poured Spot remover on my dog. Now he's gone.
Boss,What kind of trusses do you design when those valleys have to be cathedral and sheetrocked?Does the framer have to install a microlam valley or whatever type of valley first and then the trusses would be designed to fit or do you just recommend stick building cathedral valleys?Also differnt pitched roofs with cathedral valleys.Joe Carola
"What kind of trusses do you design when those valleys have to be cathedral and sheetrocked?"
Can't figure out what you're getting at...
The trouble with doing something right the first time is that nobody appreciates how difficult it was.
I meant if they are supposed to be True Valleys not layon valleys.Joe Carola
If it's a "true valley" you wouldn't be able to use trusses anyway. Assuming we're calling a "true valley" the same thing - Where you only have rafters and the ceiling is attached to the bottom of them. .If you have scissor trusses intersecting scissor trusses, I've done complete valley systems for them. They're pretty kinky, but can be done. I'll try to post an example Monday if you're interested.
Nostalgia isn't what it used to be.
Staples are the norm here, not sure about the coast.
I didn't do it....the buck does NOT stop here.
boss here's a truss roof with a concealed valley
sorry i can't find the truss photos... the main roof is scissors... the big dormer is supported by a girder truss about half way out the gable... the rest of the valley cathedral is all trusses too.
View Image
BTW... this is the job we discussed that led to the invention of the Mooney wall...
but i haven't found it in the archives yet...
3/7/2001 ..... i posted a lot of photos of this job then.. that shows the truss detail you are talking about
Mike Smith Rhode Island : Design / Build / Repair / Restore
Edited 2/12/2005 4:29 pm ET by Mike Smith
"If you have scissor trusses intersecting scissor trusses, I've done complete valley systems for them. They're pretty kinky, but can be done. I'll try to post an example Monday if you're interested."Yes I'm definetly interested in seeing them. I might have a couple houses coming up where they will use trusses. I never use them so if I'm going to start I'd better get my act together and get used to using them. If I see your pictures I can learn something about trusses and maybe look a little smart when I talk about them....;-)Joe Carola
I would like to see a picture of the cathedral ceiling scissors.
The trusses that software can come up with is amazing.
Theres a job near here that looks like a Stealth bomber roughly 300 x120x30 high.
Wild truss design (wild altogether 4x20ish' 1/4" aluminum skinned) gonna be a hobby shop.
Anyways would like to see a pic of them.
Thanks,
Dan
This is an example of scissor trusses framing into another set of scissor trusses. It's what I would call a "reverse vault". The pictures are the best I could come up with. They're not perfect, but I think they'll give you a reasonable idea of how I've done it before.
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boss, that's just how these trusses were made up..
View ImageMike Smith Rhode Island : Design / Build / Repair / Restore
When our trusses are delivered they are usually banded together in groups of 8-12. The span is usually about 30 feet. We land them in the upright position with diagonal braces. Both gable ends are already sheeted. when the crane lands the gable end bundles we put as many diagonal braces on as possible because the wind can really push them around. Most of our trussed roofs are straight gable roofs.
The layout for our trusses are put on our top plates (usually 24" OC) before our exterior walls are erected, this really saves us alot of time and effort. We put stay laths across the entire length usually about 6-8 feet up the truss so the guys on the front and back walls can tack the trusses when they are in position. Then with one guy on the front wall, one guy on the back wall, and one guy in the middle (interior walls) we spread the trusses. The trusses stay upright throughout this entire process. The trusses are are pretty easy to balance while they are being spread, But sometimes on windy days we will need a 4th guy to spread and set the gable trusses.
99% of the time the tails on our overhang are dead on. But we always string a line to double check. The only times that we run into trouble is when our walls are out of plumb or sometimes when the trusses are landed by the crane they are dropped too hard and our walls arent straight anymore. So then we have to drop back down and plumb and straighten our walls again. We use 1x8 for fascia which usually works fine but we have to hunt for nice straight long pieces which are usually hard to come by. I would rather use a 2x8, but I just do what I am told.
We sheet the first row while standing on the bottom chord of the trusses (ceiling joist). Then we put our toe boards on and sheet our way to the peak. Then we cut our roof vents, install permanent stay laths, and put blocking where necessary in between the bottom chords of the trusses to tie in the perpendicular interior walls to the trusses. Then we install our hurricane clips (metal gusset-like straps that are teco-nailed from our top plates to our trusses) and we are out of there.
This whole process usually takes about 1.5 to 2 days.
What size blocking do you use down near the plates? These are cut less than 22.5" because of the metal plates....usually closer to 22.125"? Thanks for all your comments and advice.
Have you ever installed valley trusses? Any special considerations? Thanks again.
Cut all Blocking 22 3/8. It's the best bet. I did one roof (pretty big mind you) But every little gap from a gusset or anything added up to almost 2 inches by the end of the roof. Learning that the hard way guarantees that you wont repeat it. Imagine everywhere you pull your tape it seems to be o.k. but then why are the gable ends so out of level? Do Not do that. I wasted so much time going up to the ridge knocking out blocks putting in new ones, especially after the peaks are riddled with nails. If it's a simple roof I'd build it on the ground you can get alot of the bracing ect set up atleast. You can't really do to much more unless you plan on setting a nice flat platform. Which on our sites is rare actually I don't ever recall it. We just bid on a job with over 500 trusses actually 1000 if you count the piggybacks. Our issue now is how do we space these out to avoid cumulative error. Maybee it's not even that big of a deal. I'm probably over thinking it.
Hammer, if I have to block continuous like you describe, I woud cut my blocks to 22 3/8" too.
Experience has shown that this approach works.
blueJust because you can, doesn't mean you should!
Warning! Be cautious when taking any framing advice from me. There are some in here who think I'm a hackmeister...they might be right! Of course, they might be wrong too!
Do you always need eave and ridge blocking? What size do you use? 2X6? Does that provide enough of an air gap at the eave?
Yes, where we are we need ridge blocking, It's a little easier to b/c if your cords or hoses are going up over the ridge they don't fall through it. But a bit of a pain in the but to install due to the high metal to wood ratio at the peaks of these trusses. We use 2x4, If were building subdivision we cuttem out of anything long, the wood's not of great quality anyways, If I don't use it they'll sit in the sun until they are useless for anything but blocking. If custom I set up the chopsaw infront of our scrap pile and cut lots. Always make a few extra chances are you'll need them for something. Do you deal with raised heel trusses out there? If not is there anyways to spec them?
Do you deal with raised heel trusses out there? If not is there anyways to spec them?I don't understand. The trusses I am doing are cantilevered. So, one brace at the top and one at the eave?
"Do you deal with raised heel trusses out there? If not is there anyways to spec them?"
Any truss company can manufacture trusses with whatever heel height you want. You just have to specify it.
I often get plans where they aren't called out, but they want something specific. They often tell me they want a 20" finished overhang at 9/12 with 4" from the top of the window rough openings to the underside of the sub-facsia. (Or something like that)
Personally I think cantilevering trusses is a waste of money. Why run the bottom chord out there, when it will just be hidden in the fascia?
If you were going to shoot a mime, would you use a silencer?
I meant cantilevered trusses where the bottom chords goes out and is the bottom of the fascia. This saves a good amount of time in my mind. So the heel height would be a function of overhang and pitch would give you a heel height. What type of clips do you recommend at the wall plates? Thanks for al the good info.
"I meant cantilevered trusses where the bottom chords goes out and is the bottom of the fascia."
Since aluminum soffit and fascia are the norm here, I don't think I've ever seen that done.
I suppose it could work quite well if it were planned ahead of time.
If a mime swears, does his mother make him wash his hands with soap?
Why wouldn't the bottom chord as soffit work? What are draw backs?
"Why wouldn't the bottom chord as soffit work?"
I attached a picture to show kinda what I was thinking. Don't have a CAD program at home, so I had to do it in paint.
I often see details like this one - The bottom chord is cantilevered in order to give more height above the wall. But the part of the bottom chord that sticks out beyond the wall is wasted. It may as well be cut off at the outer edge of the wall. (Where the red dashed line is) That saves lumber and money.
The fascia only touches the bottom chord if it ALL cantilever (no overhang) and the heel is raised high enough that the bottom edge of the sub-fascia is even with the bottom edge of the bottom chord.
Didn't do a drawing to show that, but I can if I'm not making myself clear.
Budget: A method for going broke methodically.
Staplers are also fairly easy to hang on the sheething. I love how light they are and I think If you nail perpendicular to the grain of the plywood it holds better than two inch nails.
This is what I was talking about. The bold line is where the soffit would end. This is a function of pitch and overhang. What is down side of using trusses like this? Thanks for your help.
The down side to a truss like this is that there is nowhere to snap a guideline to place your trusses on. I know you can use a string along the tails. My experience with this has been that the one side of the roof is perfect and the other perfectly screwed up. Also I don't know if youre required to use any system of blocking in between trusses out there. Here we almost exclusively use raised heel, in which case you can run strips of left over plywood around the house no special cutting rqd. If it's too long I break it with my hammer. It's all hidded it's only there to stop blown insulation from blowing out. Also the higher the heel the less bending you have to do to install fascia.
If one side is straight, then the other is straight but the wall is bowed. What your saying is that there is no way to straighten the wall with trusses like these????Thanks for the input.
Bhackford, since you aren't a pro at truss setting, i'd suggest a center string at the peaks.
blueJust because you can, doesn't mean you should!
Warning! Be cautious when taking any framing advice from me. There are some in here who think I'm a hackmeister...they might be right! Of course, they might be wrong too!
What do you find to be more accurate? I've never tried at the peaks before. I'm gonna give it a shot. Do you ever end up using step trusses? Most of the time this is what we have. Gables aren't to popular out here. I find every now and then the steps are off. Eg. each truss should be rising 20 inches and I'll have one at 20.5 and another at 2.75. I know you can get them in two varietys one where you run a 2x4 from girder to ridge. The other you have to make 'step ups'
Hammerhead, 90% of our jobs involve some sort of stepped down hipsets. I've never checked the steps for accuracy, but i don't doubt that they wander a little bit. Our normal method of putting the layer of "strapping" pretty much solves all the variances without too much fuss. Occasionally, we have a semi-hard time getting the hip to look straight but many years of boogering experience comes into play to get these type problems fixed in a minimum amount of time.
blueJust because you can, doesn't mean you should!
Warning! Be cautious when taking any framing advice from me. There are some in here who think I'm a hackmeister...they might be right! Of course, they might be wrong too!
Why not just measure back from each plate and equal distance? If the trusses are the same length this will work fine. I can check the trusses on the ground prior to placing. A string at the peak would seem to hard when using a crane to set them. Thanks
Bhackford, I agree that the string would make it harder to set with a crane. I only offered that suggestion because it sounded like you were slightly confused in response to the suggestiobn to set one side perfect.
We always install our cornice first and then we set our trusses to the cornice, not to the plates.
blueJust because you can, doesn't mean you should!
Warning! Be cautious when taking any framing advice from me. There are some in here who think I'm a hackmeister...they might be right! Of course, they might be wrong too!
Here is another drawing of what i was think of....
What you've drawn would certainly work.But only if it was planned correctly ahead of time. The heel height at the end of the truss would have to be correct in order for everything to fit. The PLANNING part is where everything comes up short around here. Prints are drawn with very little detail on them. Sometimes they're just floor plans sketched up on 8.5X11 paper. I realize this is only local, though. Every else they have excellent prints, right ???(-:
If your brain itched, could you scratch it by thinking about sandpaper?
Tricks for installing trusses
I had my Doctor do it for me.. I worked hard all my life.... Last lift was a bummer.
Don't suppose you'd elaborate on sheathing a roof with-out being out there? Not saying you can't, just can't picture how you do it.
I didn't do it....the buck does NOT stop here.
Most trusses are a w shape or some kind of webbed design. Trusses must be braced continuous front to back. We brace or web with 2x4 this allows us to stand on the 'ties' which usually aren't all that far inside the roof. So alot of the time I can sheet from inside the roof. By inside I mean atleast half of me is in the attic portion of the roof. I also don't sheet in straight rows from bottom to top I stagger up in steps like a shingler would. I've found this to be the fastest method I've ever used I can cover a 3000sq foot bungalow at 10/12 in about six hours with two othter guys. We also use a stapler fasten with two inch staples it's lighter and you can carry thousands of staples in your pouch, could you imagine carrying for coils of nails? Never mind I'm sure some people actually do that.
Gotcha. I do like you,too. Stagger the ply as far as I can. Everyone here staples too.We just ran our permanent bracing after the roof was on.
I didn't do it....the buck does NOT stop here.
Do staples meet code?
"Do staples meet code?"
In decking they sure do.
Tim Mooney
Decking = roof sheathing? From your last post. So staples meet code by must be stapled parallel to the trusses top chord.
Yes. Its legal on roof sheating up to 5/8s.
On a personal note it does a good job too . I used to make homeade trusses with a stapler and plywood gussets . Their impossible to pull off if theres enough staples . I like staples better because they get inpregnated into plywood and dont work out like nails.
Tim Mooney
So on 1/2 or 5/8 ply you would use 2in staples? Instead of #8's? Thanks for all the great info about staples.
Instead of #8's?
#8s are 2 1/2 inches in length and move to the category of 3/4s to 1.0 inch sheeting or boards . Then #10s to attach 1 1/2 inches and so on.
Construction staples only go to 2 inches in length , so must stop at 5/8s sheating as listed codes. Roofing staples are not code because they are against the manufactors listings now. BTW
Tim Mooney
I meant to type #6 not #8. I understand what you are saying. I just wanted to make sure the local inspector is going to give me problem which is why I was asking about code and staples.
I actualy didn't mean anything about straightening a wall I guess my chances of being an author are slim to none. What I meant to say is with the type of trusses you were showing I cannot snap a line on top of the already straight wall and then use that line to line up the heels of my trusses. However I was saying that you can line up the tails of the trusses with a string, usually doing this makes one side of your house have perfectly straight fascia, however the other side suffers greatly. All I was saying your options are somewhat limited with these style of trusses
I understand........ because the truss tails would all be the same size and when you use trusses like the ones above their is no option to adjust tail lengths to make the tails even when the trusses are different lengths.Now, the truss company told me they cut these with a laser so they will all be exactly the same size or "we would make these types of trusses". Do you think this is true? All trusses will be the same length?
Some companys take a great deal of pride in making a truly superior product. In this cas I couldn't tell you how truth full they are. I can tell you they cant cut wood with a laser or they would start a fire. I suspect ofen times it's not so much the computers that cut the wood, being the problem. You've got guys making 100bucks an hour designing the truss and guys making 10 bucks making them. I've had trusses that have 'leaned' or have dog legs in the middle of a long span right on a connector. I frequently deal with there being slightly different overhangs from one truss tail to the next. Thats why I prefer to snap a line on my wall just for the ease of layout. I've also used trusses that were perfect I guess every truss company has their own procedures and preferences I the end If your trusses are as good as this company says your final product will be much better.
They did say a "laser" but it is probably laid out with a laser. Your are right it would burn it. I am still not sure if I am going to roll the dice and do the trusses like this or do them the way you suggest. Thanks for the info.