Replies

1. 
   Gumshoe | Apr 27, 2005 08:44am | #1

   could you provide a sketch? I'm not totally clear on what you're doing, but I don't think you can do it the way you describe - a truss is an engineered member, and can't be altered without an engineered plan.

2. 
   BossHog | Apr 27, 2005 02:19pm | #2

   Not only no, but HELL NO.

   What you're proposing isn't even CLOSE to being acceptable.

   The shortest distance between two points is how far apart they are

1. 
   EricPaulson | Apr 27, 2005 06:34pm | #3

   New canidate for the Darwin awards................I Love A Hand That Meets My Own,

   With A Hold That Causes Some Sensation.

   [email protected]

1. 
   Piffin | Apr 28, 2005 12:22am | #11

   Not that bad - Darwinigans don't bother asking 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

2. 
   rez | Apr 27, 2005 06:56pm | #4

   Hey Boss, it's the guy's second post.

   Could you elaborate on the specific reasons why it is not valid? Would that be because of the new forces that would be put into play on the opposing truss side of the roof?

   Thanks. 

   sobriety is the root cause of dementia.

1. 
   EricPaulson | Apr 27, 2005 07:21pm | #5

   He's trying to extend the span of his trusses by scabbing 2x6 to the sides of the chords to bear on a new wall some distance from the one the currently rest upon.

   At the very least he would need a header at the current location of the wall to carry the trusses. But still doesn't get him a roof over the new porch. Don't have Boss' knowledge to guess if he can scab a shed roof or do a layover on the trusses to the new outside wall of the porch.

   Needs and engineer.

   EricI Love A Hand That Meets My Own,

   With A Hold That Causes Some Sensation.

   [email protected]

2. 
   BossHog | Apr 27, 2005 08:09pm | #6

   "Could you elaborate on the specific reasons why it is not valid?"

   O.K. He didn't tell us what span of truss he was dealing with. So I'll assume a 26' existing truss to use as an example.

   Assuming I understand his post, he's trying to add 14' to the span of the existing 26' trusses, so he'd have an new clear span span of 40'.

   For starters, that would put a TREMENDOUS amount of bending stress in the rafters he wants to scab alongside the existing truss. There's no way a 2X6 or 2X8 would handle that kind of bending.

   The connection between the rafters and the truss would be all but impossible. There's just no way you could get enough nails and/or bolts in there.

   And you'd be adding a lot of stress to the truss that it wasn't designed to handle. Even if the lumber was of adequate size/grade, virtually all of the plates would need to be reinforced.

   So that's it in a nutshell. I could try to run some numbers if anyone was seriously interested, but may not have time this afternoon.
   I always wanted to be a procrastinator

1. 
   rez | Apr 27, 2005 08:29pm | #7

   Thanks

   sobriety is the root cause of dementia.

3. 
   Piffin | Apr 28, 2005 12:21am | #10

   your turn to be grumpy today, eh? 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

1. 
   BossHog | Apr 28, 2005 01:23am | #12

   "your turn to be grumpy today, eh?"

   Oh shut up.

   (-:

   I was just trying to make a point in my first post that it wasn't even CLOSE to working.
   If it weren't for pickpockets I'd have no sex life at all.

1. 
   Piffin | Apr 28, 2005 02:24am | #13

   Just for the mental excercise, it would be nice if he came back with a sketch and photographs to be able to see what he is talking about more specifically 

    

   Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!

3. 
   JohnSprung | Apr 27, 2005 09:20pm | #8

   Realistically, there are two ways to deal with this:

   1.  Replace the structural function of the old exterior wall with some sort of beam.  If it's wide enough, you may have to use a post or posts to divide up the span of that beam. If the look of the beam and post(s) is unacceptable to you, then the best option is:

   2.  Sell this house to someone who will be happy with it the way it is.  Buy or build a bigger house.

   Without proper engineering, what you propose will collapse the whole house.  With proper engineering, it might collapse your bank account.  Bottom line, you'd probably be better off to sell the house and buy what you want.

    

   -- J.S.

    

    

4. 
   Piffin | Apr 28, 2005 12:20am | #9

   You really do need some on-site engineering from a pro.

   If your description is ruight - the way I read it, you now have a house that is only eight or ten feet wide. with a porch that is four or six feet wide.

   I think you are assuming that some center wall is bearing load from the truss and that your house is more like 22 to 26 feet wide at this point. your actuall clear span would then be the total. Or - it is possible that the beam on the porch is the load bearing structure for these truisses and no modification whatsoever is needed.

   by way of explanation - there is a tremendous liability in any engineering of structural work and a lot of details are needed that are missing in your information. Tbhis is not to be hard on you, but the way you present the info hints that you don't quite know what to look for in the beginning and have made some potentially dangerous assumptions.

   Trusses are very carefully designed and Boss is a truss designer. he has seen all the errors at one time or another. The thing you ARE doing right here is aasking FIRST. A lot of people wait until the failure happens and then ask why - or how do I fix this...when it is already too late.

    

    

   Welcome to the
   Taunton University of Knowledge FHB Campus at Breaktime.
    where ...
   Excellence is its own reward!

5. 
   hamjob | Apr 28, 2005 02:54am | #14

   you cannot remove the end support without replacing it with something.cut off the tails and install a flush beam so that the truss end is hanging off the beam.beam will have to be engineered,as it will act as a girder.new rafters can be added on top of the truss as long as you provide support from the new beam to the underside of the new rafter.either way , get an engineer involved .

    

   There's nothing we can't do twice!