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View Full Version : Trusses..Who can answer a question...


Workin' 4 Toys
01-11-2007, 09:36 AM
Who can help me with a "load" question on trusses...?

Upper Michigan Prostar190
01-11-2007, 09:51 AM
I could have when I was in college. I was an ace student in statics. Dealt with all kinds of stuff like that. I dont know if I remember much of it now though. I would have to go digging through my attic and find my statics text book and refresh myself. I can try though.

Whats your question? If I cant help you, maybe someone else can....

Evan Jones
01-11-2007, 10:19 AM
I might be able to. We have a truss designer on staff here at the lumberyard.

Evan Jones
01-11-2007, 10:55 AM
I might be able to. We have a truss designer on staff here at the lumberyard.

Oooops ....double post

bobbyB
01-11-2007, 12:22 PM
hey workin

I should be able to answer any loading ?'s you've got about truss'.

Steve (BobbyB)

Workin' 4 Toys
01-11-2007, 01:29 PM
I will "return" here soon with more details than I remember to bring with me...:o

phecksel
01-12-2007, 01:58 AM
I will "return" here soon with more details than I remember to bring with me...:o



if you're trying to resolve a strength question, I might suggest this is the wrong venue. Get the problem incorrectly stated, or not properly understood, and it could be an issue. If it's a house truss issue, at the very least wander over to a full service lumber yard and request local help.

kycat2007
01-12-2007, 02:15 AM
this could be a good site
http://www.contractorcity.com/modules.php?name=Forums&file=viewtopic&t=449

http://www.hometime.com/Howto/projects/framing/frame_5.htm

http://www.chiefarchitect.com/support/searchresults.php?B1=Submit&SEARCH_STYLE=SUBJECT&subject=trusses

Workin' 4 Toys
01-12-2007, 09:13 AM
Ok, so I can't find my drawing:o so I can't give you the exact info on what I have....So I will describe what I want to do. This was a major oversite on my part NOT having this done prior...:o
I have what I believe is called a double fink. They are approx 48' long with a 6/12 pitch.
I would like to have storage space "within" them. And I considered just laying plywood over the bottom chord, but instead I hope I can add some webs or braces to be able to create a "shelf". I hope to be able to do something without changing the structural integrity of the system.

Any suggestions....???

Maristar210
01-12-2007, 09:13 AM
I could have when I was in college. I was an ace student in statics. Dealt with all kinds of stuff like that. I dont know if I remember much of it now though. I would have to go digging through my attic and find my statics text book and refresh myself. I can try though.

Whats your question? If I cant help you, maybe someone else can....


So long ago apprently that the spelling of the word "statisitics" escapes him as well. Eh UMP?

Static is what Ms. UMP is giving you for not pulling out the rock...:D

Workin' 4 Toys
01-12-2007, 09:20 AM
if you're trying to resolve a strength question, I might suggest this is the wrong venue. Get the problem incorrectly stated, or not properly understood, and it could be an issue. If it's a house truss issue, at the very least wander over to a full service lumber yard and request local help.
This is always the proper venue for tips and ideas. ;)
Obviously, I could even go back to the manufacturer of the truss, but I'd rather get some ideas and tips here.....:D
Or worse case scenario, I get an idea here, and then I go to the manufacturer and question them....;)

Workin' 4 Toys
01-12-2007, 09:23 AM
So long ago apprently that the spelling of the word "statisitics" escapes him as well. Eh UMP?

Static is what Ms. UMP is gving you for not pulling out the rock...:DAnd I thought East tx skier was our grammar/spelling expert....good call Mr. gving.....:rolleyes:

Evan Jones
01-12-2007, 09:52 AM
Most of the designers add in enough load to handle light storage up within the webs. Putting plywood down on the bottom chord, or adding webs or chords usually isn't an issue. Cutting or notching existing structural pieces is out of the question. Putting in some blocking to create shelves does not affect the structural integrity of the truss if this is what you intend to do. If you are going to use it for more than light storage, you may want to have an engineer look at it.

bcampbe7
01-12-2007, 09:55 AM
UMP is an Enginerd and is only like 8 hours from you. I am sure he wouldn't mind throwing on his cape and coming down to help you out. :D

Workin' 4 Toys
01-12-2007, 09:58 AM
UMP is an Enginerd and is only like 8 hours from you. I am sure he wouldn't mind throwing on his cape and coming down to help you out. :D
Yes, but then that opens me up to help him install his whole house heated exhaust lamp.... And I don't dare touch one of those.....:purplaugh

Maristar210
01-12-2007, 09:58 AM
And I thought East tx skier was our grammar/spelling expert....good call Mr. giving.....:rolleyes:

Uh huh?.......

bcampbe7
01-12-2007, 10:01 AM
Yes, but then that opens me up to help him install his whole house heated exhaust lamp.... And I don't dare touch one of those.....:purplaugh


Good point! :D

Workin' 4 Toys
01-12-2007, 10:02 AM
Most of the designers add in enough load to handle light storage up within the webs. Putting plywood down on the bottom chord, or adding webs or chords usually isn't an issue. Cutting or notching existing structural pieces is out of the question. Putting in some blocking to create shelves does not affect the structural integrity of the truss if this is what you intend to do. If you are going to use it for more than light storage, you may want to have an engineer look at it.
Where, within the truss is the ideal location for adding webs & chords for what I want to do...?

Meaning...If I had them built with a storage area within the truss, where would that area be?

Upper Michigan Prostar190
01-12-2007, 10:03 AM
So long ago apprently that the spelling of the word "statisitics" escapes him as well. Eh UMP?

Static is what Ms. UMP is giving you for not pulling out the rock...:D

HA! Thats OK staristar! I dont mind that static, its just like radio static, I just tune it out!:D

Statics baby! STATICS! S-T-A-T-I-C-S !!! the study of items that are not moving. Its like physics, without motion. Study of forces acting on things while at rest. UMP is not a statatician. I dont do that game. :cool:

Upper Michigan Prostar190
01-12-2007, 10:06 AM
UMP is an Enginerd and is only like 8 hours from you. I am sure he wouldn't mind throwing on his cape and coming down to help you out. :D
Thats right! beau speaks da troof! Better listen to me Flounder, I am pre-med!:D

Workin' 4 Toys
01-12-2007, 10:07 AM
Uh...huh...Should I run for governor or senator?.......
Now I see how you work:rolleyes: ....You edit other's quotes8p ....Quick thinking:rolleyes:







Edit: Now I know why I try NOT to make fun of other's typing skills when I need to concentrate on my hunt and peck technique...

Upper Michigan Prostar190
01-12-2007, 10:14 AM
Yes, but then that opens me up to help him install his whole house heated exhaust lamp.... And I don't dare touch one of those.....:purplaugh
Hey, the heat lamp is coming soon. The floor guy is supposed to do the floor soon, then I will install the lamp. :)

Maristar210
01-12-2007, 10:20 AM
HA! Thats OK staristar! I dont mind that static, its just like radio static, I just tune it out!:D

Statics baby! STATICS! S-T-A-T-I-C-S !!! the study of items that are not moving. Its like physics, without motion. Study of forces acting on things while at rest. UMP is not a statatician. I dont do that game. :cool:


Okay UMPster, I got it......

Maristar210
01-12-2007, 10:21 AM
Now I see how you work:rolleyes: ....You edit other's quotes8p ....Quick thinking:rolleyes:







Edit: Now I know why I try NOT to make fun of other's typing skills when I need to concentrate on my hunt and peck technique...


Good Morning WFT. How are you today?

Have a good day WFT:D

Workin' 4 Toys
01-12-2007, 10:21 AM
Hey, the heat lamp is coming soon. The floor guy is supposed to do the floor soon, then I will install the lamp. :)
Be careful, pulling all 3 of those #4 THHN is going to be a tight squeeze through that 3/4"....You will probably need some lube....:rolleyes: :rolleyes: :rolleyes:

Workin' 4 Toys
01-12-2007, 10:24 AM
Good Morning WFT. How are you today?

Have a good day WFT:D
My "work" day is 1/3 over and I am on my 3rd cup of coffee, so I guess it is almost a perfect day....And doing well. How about yourself....?

Evan Jones
01-12-2007, 10:26 AM
Where, within the truss is the ideal location for adding webs & chords for what I want to do...?

Meaning...If I had them built with a storage area within the truss, where would that area be?

Usually right inthe middle where the headroom is highest

Workin' 4 Toys
01-12-2007, 10:36 AM
Usually right inthe middle where the headroom is highest
Ok, but this is more along the lines of what I have to work with....:confused:

Upper Michigan Prostar190
01-12-2007, 10:39 AM
Okay UMPster, I got it......
Its all cool Steve, I know you were just bustin my chops. :) ITs FRIDAY! live a little!:D

milkmania
01-12-2007, 10:48 AM
Ok, but this is more along the lines of what I have to work with....:confused:

http://www.runningscared.org/files/jazz-screwed.gif


;) just messin' with ya

Workin' 4 Toys
01-12-2007, 11:02 AM
http://www.runningscared.org/files/jazz-screwed.gif


;) just messin' with ya
Yeah, yeah......I just wish someone would have told me to do this BEFORE.....I guess this is a note to self item......

milkmania
01-12-2007, 11:06 AM
Yeah, yeah......I just wish someone would have told me to do this BEFORE.....I guess this is a note to self item......

that's the reason gambrel styled roofs are appealing to me.......

outside
http://i5.ebayimg.com/01/i/05/9a/16/2f_1.JPG


inside second floor
http://i6.ebayimg.com/04/i/05/93/d1/a5_1.JPG

Workin' 4 Toys
01-12-2007, 11:24 AM
Milk....So you are saying you would rather have everything on the FLOOR....
Thats' all great having floor space, I have no problems there..It's the little sh*t I need to put somewhere....I HATE clutter!!! And the little sh*t I don't need to look at needs to go in the attic so I only need to see it when I want to. And this area I need help with is above a portion of the garage.
So, in a nutshell, I sort of have what you show in the picture, but what I have "included" is several mounting points for shelves I can walk through, around, and in between:D I just need to utilize the space (without sacrificing structural integrity) to the best of my ability....;)

milkmania
01-12-2007, 11:30 AM
Milk....So you are saying you would rather have everything on the FLOOR....
Thats' all great having floor space, I have no problems there..It's the little sh*t I need to put somewhere....I HATE clutter!!! And the little sh*t I don't need to look at needs to go in the attic so I only need to see it when I want to. And this area I need help with is above a portion of the garage.
So, in a nutshell, I sort of have what you show in the picture, but what I have "included" is several mounting points for shelves I can walk through, around, and in between:D I just need to utilize the space (without sacrificing structural integrity) to the best of my ability....;)

I'm looking into it as more of a cabin for myself:cool:

drove up to northern arkansas to a display..... a 24 x 24 gambrel styled building had a 21.5' centr peak height..... standing on the second floor.... I couldn't jump up and touch the peak inside.

The foundation that I'm wanting to build on is 30wide x 40long, so it'll come out a little taller even.

Evan Jones
01-12-2007, 11:33 AM
I assume they are 24" on center. You are fairly limited by the low pitch, and the webs, but you can certainly put in 22-1/2" wide shelves in between each truss, and plywood on the "floor" to walk around on.

Workin' 4 Toys
01-12-2007, 11:38 AM
I'm looking into it as more of a cabin for myself:cool:

drove up to northern arkansas to a display..... a 24 x 24 gambrel styled building had a 21.5' centr peak height..... standing on the second floor.... I couldn't jump up and touch the peak inside.

The foundation that I'm wanting to build on is 30wide x 40long, so it'll come out a little taller even.
I see you keep increasing the size of this building, if you wait much longer you might as well just do the 60' X 80' cause thats where you're headed...
I recall your first inquiry about building a shed...It was a "coupon" you had magneted to the fridge and you wanted to know if it looked $ right. And If I recall it was no 30X40...Steel also if I recall.
When is this project getting underway...?

milkmania
01-12-2007, 11:41 AM
I see you keep increasing the size of this building, if you wait much longer you might as well just do the 60' X 80' cause thats where you're headed...
I recall your first inquiry about building a shed...It was a "coupon" you had magneted to the fridge and you wanted to know if it looked $ right. And If I recall it was no 30X40...Steel also if I recall.
When is this project getting underway...?

that was before the wife problems
there's legal issues that need sorted out first...
ie: MY money vs. HER money;)







I've found 15 acres that has a foundation started and it's dimensions are 30 x 40.... no concrete poured, so I can still get my plumbing in.

Workin' 4 Toys
01-12-2007, 11:46 AM
I assume they are 24" on center. You are fairly limited by the low pitch, and the webs, but you can certainly put in 22-1/2" wide shelves in between each truss, and plywood on the "floor" to walk around on.
I was thinking more along the lines of this (blue lines) spanning the entire space....your thoughts??

phecksel
01-12-2007, 12:13 PM
I was thinking more along the lines of this (blue lines) spanning the entire space....your thoughts??
Be very careful you're not changing load paths. Also concerned about putting much of any shear load on a structural joint that's currently not in shear. You could probably get away with exactly what you want to do and never have a problem, but the history books are filled with study cases of structural failures that didn't consider that one case. I would have far less concern with the floor being used for storage, or very light object only stored like you're proposing.

PendO
01-12-2007, 12:22 PM
Why not just go to a place that builds trusses? Fabricated trusses are nice, because they all match:) and the engineering is all done for you.

15-20 years ago we added on to our cabin and built trusses to match the current pitch, ended up having to take our design to a structural engineer to get stamped, then the building inspector would sign off

Workin' 4 Toys
01-12-2007, 12:56 PM
Why not just go to a place that builds trussesI did, these have been mine for about a month....:o I didn't think of it at the time.....
Of the thousands of things people suggest, and millions of things on ones mind going into a project, sometimes the obvious ideas are overlooked.

Workin' 4 Toys
01-12-2007, 01:02 PM
Be very careful you're not changing load paths. Also concerned about putting much of any shear load on a structural joint that's currently not in shear. You could probably get away with exactly what you want to do and never have a problem, but the history books are filled with study cases of structural failures that didn't consider that one case. I would have far less concern with the floor being used for storage, or very light object only stored like you're proposing.
I would prefer not to be a study case;)

bobbyB
01-12-2007, 02:07 PM
Hey Workin

I work as a plans examiner for a county out here in Washington State, and Truss' are one of those "touchy" areas we deal with all the time. Here's what you need to know.

If you could put some ply down on the bottom cord of the truss [U]without [U] trying to modiefy it, light storage is most likely OK. Truss manufactures generally overengineer there products by 150% to compensate for this type of situation. Would the truss company admit this to the public?? No, probably not; however light storage like boxes would be fine.

Here's the thing you have to know! Don't modify the truss in anyway. No cutting, knotching, holes or removal of parts. Doing things like this will void your warrenty in a heart beat. It used to be that truss companies over built there stuff with only the best lumber available, not so much anymore. Due to compeditive nature of the industries, they've had to start useing lesser grades of lumber and smaller sizes. Used to be it was all Select grade 2x4's and 2x6's, now were seeing 2x3's and even some 2x2's. So, modifying your truss from a standard to an attic truss would involve going back to the manufacturer for an approved fix. By the time you got done messing with it you could probably buy new attic truss' and put a whole new roof on.

Here's an idea that I've seen used out there. Instead of trying to run your ply perpendicular to the truss', try running a 22 1/2" x 8' strip inbetween the bottom cords of the truss. Nail a backing strip to the side of the bottom cord of the truss and then put your ply on top of the backing strip. Most boxes will fit in a 22 1/2" wide space anyway.

Kind of a long winded reply...but I didn't want to see you go down that road. ;)

B

Workin' 4 Toys
01-12-2007, 03:06 PM
I think it has been mentioned before about modifying the trusses. I have absolutely no intentions whatsoever of doing so even slightly. What I want to do is add framing in ideal locations to best utilize the space available.
I just want the absolute sturdiest shelf for sh*t...not even boxes so much.
For example: christmas trees, lights, decorations, other holiday decorations, old bikes, outdoor furniture, extra furniture like chairs & stools,...you get the idea.

bobbyB
01-12-2007, 07:19 PM
Workin

You should be able to put some additional framing up there to build shelving out of as long as you keep the amount of weight to a minimum. Start getting to much load up there and all bets are off.

Of coarse if you happen to be like my brother in law who's a pack rat, then soon you'll be testing the limits. :o He has WAY more stuff packed up in his garage truss' than I'd be comfortable with. Just remember, no building goes on over the MasterCraft! Man-law #632;)

phecksel
01-12-2007, 11:04 PM
I think it has been mentioned before about modifying the trusses. I have absolutely no intentions whatsoever of doing so even slightly. What I want to do is add framing in ideal locations to best utilize the space available.
I just want the absolute sturdiest shelf for sh*t...not even boxes so much.
For example: christmas trees, lights, decorations, other holiday decorations, old bikes, outdoor furniture, extra furniture like chairs & stools,...you get the idea.
How are you going to attach shelving to the trusses? Nails or screws, might change load paths. I would rather see shelving sitting loose, but all that "stuff", you're going to drag up other can start adding something other then insignificant wt.

Workin' 4 Toys
01-16-2007, 10:03 AM
How are you going to attach shelving to the trusses? Nails or screws, might change load paths. I would rather see shelving sitting loose, but all that "stuff", you're going to drag up other can start adding something other then insignificant wt.
I intend on using gang nail plates to attach an added "chord" in the center. Please excuse my terminology, but I am unsure what to call a horizontal "web" in the center of a truss...

phecksel
01-16-2007, 12:20 PM
I intend on using gang nail plates to attach an added "chord" in the center. Please excuse my terminology, but I am unsure what to call a horizontal "web" in the center of a truss...
As soon as you "tie" with something like gang nail plates, you have effectively changed the load path. Good or bad, I can't answer that question without pulling out UMP's statics books. I would much rather see something like a shelf bracket on both sides with a loose fitting shelf.

Workin' 4 Toys
01-16-2007, 01:04 PM
As soon as you "tie" with something like gang nail plates, you have effectively changed the load path. Good or bad, I can't answer that question without pulling out UMP's statics books. I would much rather see something like a shelf bracket on both sides with a loose fitting shelf.
I guess I need to find that out.....:o

Workin' 4 Toys
04-30-2007, 10:18 AM
BEFORE I go to the manufacturer...............;)

I am looking to build a little shack out back. The "building" will be exactly 12' wide outside to outside. Off to the left of it, I want a 6' overhang for a porch plus added overhangs on both sides for water and snow run off. I would prefer to not have any structural supports under itthe left side. I will add a couple posts for looks and allow me to attach some screening, but I do not want to "require" them. Can this be done successfully? Any other suggestions?

djhuff
04-30-2007, 10:56 AM
6' is a long way to cantilever with 12' behind the cantilever. It is within spec(barely), but with a snow load, those are going to be expensive trusses.

It would be very easy to get a post on each end and a beam across the whole opening of the porch

Workin' 4 Toys
04-30-2007, 01:47 PM
You have no idea how much the price would increase if I required structural support posts. Let me put it into perspective. It would then require a 42" deep foundation/footing around the entire building. The posts need to be "decorative" not "structural".
Techinically the building would be 12' and the roof would be 19' wide with the cantilever and additional 6" overhangs on the sides.
Are you saying you would not suggest doing it this way? Do you have an alternative suggestion? (I didn't really want to go the awning route.....)

djhuff
04-30-2007, 04:35 PM
Talk to the truss manufacturer, they will more than likely work with you on this. Do you get a lot of wind?? The uplift on a 6x12' overhang is going to be something fierce and that wall is going to have to be anchored pretty well to handle that (will probably be in the neighborhood of 1500-2000 lbs per truss is my guess)

Ric
04-30-2007, 04:41 PM
BEFORE I go to the manufacturer...............;)

I am looking to build a little shack out back. The "building" will be exactly 12' wide outside to outside. Off to the left of it, I want a 6' overhang for a porch plus added overhangs on both sides for water and snow run off. I would prefer to not have any structural supports under itthe left side. I will add a couple posts for looks and allow me to attach some screening, but I do not want to "require" them. Can this be done successfully? Any other suggestions? Anybody else hear that? I think I just heard banjos playing?????

PendO
04-30-2007, 04:47 PM
Anybody else hear that? I think I just heard banjos playing?????

Don't they sell a distillery kit at Costco?

TX.X-30 fan
04-30-2007, 04:57 PM
Anybody else hear that? I think I just heard banjos playing?????



Yeah Yeah I can hear it now.


21394


:eek:

Ric
04-30-2007, 05:02 PM
hahhaha I can see each one except granny, I cannot figure out who that is supposed to be

PendO
04-30-2007, 05:04 PM
hahhaha I can see each one except granny, I cannot figure out who that is supposed to be

Ms. Rice ..........................

Ric
04-30-2007, 05:05 PM
Ms. Rice .......................... huh uhhh ellie may is ms Rice 8p

Maristar210
04-30-2007, 05:10 PM
huh uhhh ellie may is ms Rice 8p


Ooooo Ellie May

Where's the shampoo?

TX.X-30 fan
04-30-2007, 05:10 PM
Rove??????

Workin' 4 Toys
05-02-2007, 09:45 AM
Anybody else hear that? I think I just heard banjos playing?????hmmmmmmmmm....Must be a Texas thing...:confused: What would this imply?

Workin' 4 Toys
05-02-2007, 09:52 AM
Talk to the truss manufacturer, they will more than likely work with you on this. Do you get a lot of wind?? The uplift on a 6x12' overhang is going to be something fierce and that wall is going to have to be anchored pretty well to handle that (will probably be in the neighborhood of 1500-2000 lbs per truss is my guess)
See, I am glad I started here. You talked me out of it. I am going to build the roof. And the "overhang" will no longer be an overhang or a cantilever. I will resort back to traditional methods and just build a screen porch off the side.
Thanks for the tips...;)

Workin' 4 Toys
05-02-2007, 09:54 AM
Don't they sell a distillery kit at Costco?
I thought you may appreciate the "shack" comment. Would you prefer I just call it a Shed as it will be? Or will you still assume I will be making moonshine?

Ric
05-02-2007, 12:04 PM
hmmmmmmmmm....Must be a Texas thing...:confused: What would this imply? ever seen the movie Deliverance? Of course you have and you know what the banjos imply. Thanks for playing though. How many dogs will you be able to fit under the porch by the way?

Workin' 4 Toys
05-02-2007, 02:11 PM
ever seen the movie Deliverance? Of course you have and you know what the banjos imply. Thanks for playing though. How many dogs will you be able to fit under the porch by the way?
I have never seen that movie. Althought as many times I have heard references to it and never heard of the banjos. but thats ok, maybe one day when I have nothing to do, I will rent it.
The porch floor will be a 6" thick concrete slab, so I hope there will not be any dogs under there.

Ric
05-02-2007, 09:05 PM
I have never seen that movie. Althought as many times I have heard references to it and never heard of the banjos. but thats ok, maybe one day when I have nothing to do, I will rent it.
The porch floor will be a 6" thick concrete slab, so I hope there will not be any dogs under there. It is something you should see while Ned Beatty is still alive anyway