If you were Registered and logged in, you could reply and use other advanced thread options
|
Posted by Alan on August 6, 2006, 3:03 am
Thanks guys for the feedback and ideas. By way of clarification, the
two garage doors headers will distribute point load for 5 trusses. 3
of those, the planning architect said were OK. Incidentally, I
actually don't have any problem with him because he protects me from
the ineptitude of the truss designers who would just as well sell
anything to a DIYer. The two heavy trusses are over different garage
doors, which is good. But, if I have two heavy point loads over two
doors, the header distributes this to three loads, with the heaviest
being on the 8" wide post between the doors. Jackhammering the garage
floor slab on one side, and tearing up my foundation drainage system on
the other seems like a real bummer, not to mention that I'd have to dig
down at least 18" before I can undermine the foundation to shore it up.
The other side of the house is also a hassle.
Isn't there a way to build an intersecting web truss system to transfer
some load to the two sides of the garage foundation hardly loaded at
all? Does the Mitek software used by the truss company calculate loads
in a complex manner to take into account support by adjacent trusses?
I've got a good solid foundation around the perimeter of this garage,
so again, it seems to me the problem is how to distribute loads more
equally on all four sides. But, this is my first month of experiencing
the world of trusses in any meaningful sense. Last month, I was
stumped by how to create dormer space without interfering webs, but now
that dormer with all its bells and whistles is causing a big load
problem.
Additional ideas welcomed so that I can help out my techie truss
designer if I can.
Alan
Wayne Whitney wrote:
>
> > Are you suggesting that if I rip off the top plate, and down the
> > studs, say 12" or so, and install a header into the void to make-up
> > back to the height of the original top plate, I would effectively be
> > able to convert the point loads into weight distributed along all
> > the studs and the axis of the entire wall foundation, or a least
> > also whatever is the length of the header?
>
> A header will distribute the loads from above (usually a distributed
> load, but in your case a point load) into two point loads, one at each
> end of the header. So the advantage in your case is to take a single
> point load and transform it into two offset point loads half the size.
>
> Cheers, Wayne
|
|
Posted by Bob Morrison on August 7, 2006, 10:21 am
In a previous post Alan wrote...
> Thanks guys for the feedback and ideas. By way of clarification, the
> two garage doors headers will distribute point load for 5 trusses. 3
> of those, the planning architect said were OK. Incidentally, I
> actually don't have any problem with him because he protects me from
> the ineptitude of the truss designers who would just as well sell
> anything to a DIYer.
>
Wrong!
You poured the foundation BEFORE you had a complete design and then you
designed a roof shape that didn't meet the capabilities of the foundation.
It is not the the truss manufacturer's fault. It's yours!
--
Bob Morrison, PE, SE
R L Morrison Engineering Co
Structural & Civil Engineering
Poulsbo WA
bob at rlmorrisonengr dot com
|
|
Posted by Alan on August 8, 2006, 2:55 pm
I definetly accept responsibility for not seeing the full world of
design options available to me for this retrofit garage rebuilt
project, but the truss company did have at it's disposal information
about the walls and foundation AND designed trusses that would have
blown out the foundation anyway. Thank goodness for government
bureaucrats because they can rescue the DIY from product selling
companies! Also, the software designing the trusses are only 2D, so
the maxtrix of trusses as a whole aren't calculated, and so strongbacks
and intersecting truss designs are apparently not yet possible for the
techie using the Mitek software. This leaves the engineer to bruise
his finger tips in tabulation of this information, like the good old
slave days before computers---perhaps several hours work.
I do have an engineer working with me on this now, and he's confident a
simple solution can work out, and that the truss company will have a
chance to deliver a good product. But, Bob, could you clarify those
retrofit foundation techniques again? The last one does sound
interesting, but I've never heard of these before. If the installed
header strategies can't overcome foundation limitations, we may yet
need to do some digging...
Alan
Bob Morrison wrote:
> In a previous post Alan wrote...
> > Thanks guys for the feedback and ideas. By way of clarification, the
> > two garage doors headers will distribute point load for 5 trusses. 3
> > of those, the planning architect said were OK. Incidentally, I
> > actually don't have any problem with him because he protects me from
> > the ineptitude of the truss designers who would just as well sell
> > anything to a DIYer.
> >
> Wrong!
>
> You poured the foundation BEFORE you had a complete design and then you
> designed a roof shape that didn't meet the capabilities of the foundation.
> It is not the the truss manufacturer's fault. It's yours!
>
> --
> Bob Morrison, PE, SE
> R L Morrison Engineering Co
> Structural & Civil Engineering
> Poulsbo WA
> bob at rlmorrisonengr dot com
|
|
Posted by Chas Hurst on August 8, 2006, 3:43 pm
>I definetly accept responsibility for not seeing the full world of
> design options available to me for this retrofit garage rebuilt
> project, but the truss company did have at it's disposal information
> about the walls and foundation AND designed trusses that would have
> blown out the foundation anyway. Thank goodness for government
> bureaucrats because they can rescue the DIY from product selling
> companies! Also, the software designing the trusses are only 2D, so
> the maxtrix of trusses as a whole aren't calculated, and so strongbacks
> and intersecting truss designs are apparently not yet possible for the
> techie using the Mitek software. This leaves the engineer to bruise
> his finger tips in tabulation of this information, like the good old
> slave days before computers---perhaps several hours work.
>
> I do have an engineer working with me on this now, and he's confident a
> simple solution can work out, and that the truss company will have a
> chance to deliver a good product. But, Bob, could you clarify those
> retrofit foundation techniques again? The last one does sound
> interesting, but I've never heard of these before. If the installed
> header strategies can't overcome foundation limitations, we may yet
> need to do some digging...
>
> Alan
>
Could you put the door in the gable end?
|
|
Posted by Bob Morrison on August 8, 2006, 5:46 pm
In a previous post Alan wrote...
> I do have an engineer working with me on this now, and he's confident a
> simple solution can work out, and that the truss company will have a
> chance to deliver a good product. But, Bob, could you clarify those
> retrofit foundation techniques again? The last one does sound
> interesting, but I've never heard of these before. If the installed
> header strategies can't overcome foundation limitations, we may yet
> need to do some digging...
>
Alan:
Information on the helical anchor solution can be found at
http://www.abchance.com/ch_app/underpin_frep.html
--
Bob Morrison, PE, SE
R L Morrison Engineering Co
Structural & Civil Engineering
Poulsbo WA
bob at rlmorrisonengr dot com
|
Page 2 of 3 < 1 2 3 > last >>
| Similar Threads | Posted | | Truss Calculations again...different issue | August 12, 2006, 3:16 am |
| Standby Load, Plug Load | February 5, 2008, 9:36 pm |
| Please point me to a link with a picture of a valve seating tool | March 1, 2007, 2:26 pm |
| HVAC calculations | May 11, 2008, 5:39 pm |
| Is my sunroom included in square footage calculations? | December 2, 2006, 8:42 pm |
| Wood-I or Open Truss Joists? | April 25, 2008, 8:35 am |
| Re: Wood-I or Open Truss Joists? | May 1, 2008, 11:32 am |
| Blocking in Basement between open Truss and rim joist | November 20, 2006, 3:33 pm |
| Finishing garage with truss roof system | May 14, 2007, 11:48 am |
| Load capacity of garage pad | September 5, 2006, 12:40 pm |
|
|
Yahoo! 
Google 
Windows Live 
del.icio.us 
digg 
Netscape 
XML Sitemap