jamesbuk
Posts: 3712
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Help Needed With A Roof Structure!

Sun Sep 10, 2006 6:36 am

Hi guys and gals,

My friend has a typical garage next to his house, a pointy roof one, believe its called a Gable or an upside down V for a roof. Now the bit were the beams run across above about 10 foot up we have boarded it with floorboards, carpeted and installed electric and water (all single handedly) now we were interested whether its safe to remove the diagonal bars. The ones that run from the bottem middle of the roof up to half way of the roofing diagonal bar, Would this be safe?
If so could you please provide maybe a link or back up your statement as we would like to present this data to his father to get permission.

Rgds --James--
You cant have your cake and eat it... What the hells the point in having it then!!!
 
RichardPrice
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RE: Help Needed With A Roof Structure!

Sun Sep 10, 2006 6:46 am

Time to learn two lessons:

1. engineers seldom include structural features that arent necessary.

2. contractors dont over build, they dont spend on materials that are stronger than required.

Get a builder in, get a professionals opinion. Getting building advice on a forum is the same as getting legal advice on a forum - extremely dangerous and both may have you ending up in prison.
 
jamesbuk
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RE: Help Needed With A Roof Structure!

Sun Sep 10, 2006 6:51 am

Ok erm dont really know what to say,

Quoting RichardPrice (Reply 1):
both may have you ending up in prison.

Why would this be?

rgds --James--
You cant have your cake and eat it... What the hells the point in having it then!!!
 
RichardPrice
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RE: Help Needed With A Roof Structure!

Sun Sep 10, 2006 6:55 am

Quoting Jamesbuk (Reply 2):
Why would this be?

1. Bad legal advice can give you a contempt of court ruling, or lead you to make the wrong decision.

2. Bad engineering advice can result in a structure failing, injuring or potentially killing someone. The person or people that caused that structure to fail, by, say, altering the structure, will get charged with manslaughter or other charges.
 
jamesbuk
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RE: Help Needed With A Roof Structure!

Sun Sep 10, 2006 7:02 am

So you think we should leave it how it is? that is if we dont get a pro in to tell us what we would be able to do?

Rgds --James--
You cant have your cake and eat it... What the hells the point in having it then!!!
 
RichardPrice
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RE: Help Needed With A Roof Structure!

Sun Sep 10, 2006 7:12 am

Quoting Jamesbuk (Reply 4):
So you think we should leave it how it is? that is if we dont get a pro in to tell us what we would be able to do?

Yes, I think you should leave it unless you get a professional in to advise you on what to strengthen.

Spend the money, get the professional in both prior to making the modification, and after the modification so he can sign off on it. If anything goes wrong then, its his problem and not yours.

When you pay big money for professionals, usually a large chunk of that goes to their insurance company for precisely these reasons.
 
jamesbuk
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RE: Help Needed With A Roof Structure!

Sun Sep 10, 2006 7:20 am

Quoting RichardPrice (Reply 5):

Ok well i dont think we are prepared to pay a chunk of money to be cleared to knock some beams down, thanks for your advice mate.

Rgds --James--
You cant have your cake and eat it... What the hells the point in having it then!!!
 
bhmbaglock
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RE: Help Needed With A Roof Structure!

Sun Sep 10, 2006 9:05 am

Quoting RichardPrice (Reply 1):
1. engineers seldom include structural features that arent necessary.

Stick framed roof stuctures are rarely designed by engineers. In the US for example, only FL and CA require this in most cases.

Quoting RichardPrice (Reply 1):
2. contractors dont over build, they dont spend on materials that are stronger than required.

Actually this can be argued. Most roof stuctures are stick framed when a stronger roof using much less material is possible using trusses.

Jamesbuk,

I can probably answer your question if you can e-mail me a few pictures and let me know the dimensions of the building. I grew up in the construction and truss business and have designed several thousand roofs, mostly trussed but quite a few stick framed and hybrid as well.
Where are all of my respected members going?
 
RichPhitzwell
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RE: Help Needed With A Roof Structure!

Sun Sep 10, 2006 10:18 am

The diagonals are very important...This is where the strength and rigidity come from.
Nonav.com kinda like Whiners except the lights are on and the pimps been paid
 
L-188
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RE: Help Needed With A Roof Structure!

Sun Sep 10, 2006 10:23 am

Quoting BHMBAGLOCK (Reply 7):
Actually this can be argued. Most roof stuctures are stick framed when a stronger roof using much less material is possible using trusses.

Agreed, most roofs are build with standard dimensional lumber. So if you could get away with using a 2x5 for example you are stick with the 2x6 because that is the size available and therefore you have a stronger piece of wood then needed.

That being said, it should be possible to redesign the trusses that are installed into a scissors truss or some other arrangement, but as has been mentioned here those trusses where built that way for a reason, so I wouldn't suggest taking them out..

In fact my brother just redid all the roof trusses in my mom's new house. He did one at at time because of strength issues.
OBAMA-WORST PRESIDENT EVER....Even SKOORB would be better.
 
CanadianNorth
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RE: Help Needed With A Roof Structure!

Sun Sep 10, 2006 10:36 am

My opinion on this sort of thing: If someone went to all the bother of putting it there, then it's probably there for a reason.

You could probably redesign and redo your current setup no problem, but I would recommend either getting someone who knows what they are doing, or just leaving it the way it is for now.


CanadianNorth
What could possibly go wrong?
 
fr8mech
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RE: Help Needed With A Roof Structure!

Sun Sep 10, 2006 10:41 am

A roof is designed as a system. The system is designed to transmit its own weight to the ground through a path specified either through an engineer or architect.

If you have a gable roof, you probably have a truss system. The diaganol members you describe are probably the web memebers. Do they run from the rafter to the joist or plate? From your description, it appears that they do. If they are the diagnol members, DO NOT remove them. The truss will become unstable and may collapse.

This advise from a former firefighter who was qualified to perform fire inspection. That means I was trained in building construction.

http://harvey.wisd.net/~efricks/CONSTRUCTION/ROOFING.htm

[Edited 2006-09-10 03:43:07]
When seconds count...the police are minutes away.
 
RichPhitzwell
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RE: Help Needed With A Roof Structure!

Sun Sep 10, 2006 3:01 pm

Quoting L-188 (Reply 9):
Quoting BHMBAGLOCK (Reply 7):
Actually this can be argued. Most roof stuctures are stick framed when a stronger roof using much less material is possible using trusses.

Agreed, most roofs are build with standard dimensional lumber. So if you could get away with using a 2x5 for example you are stick with the 2x6 because that is the size available and therefore you have a stronger piece of wood then needed.

That being said, it should be possible to redesign the trusses that are installed into a scissors truss or some other arrangement, but as has been mentioned here those trusses where built that way for a reason, so I wouldn't suggest taking them out..

In fact my brother just redid all the roof trusses in my mom's new house. He did one at at time because of strength issues.

Absolutely agree, it is possible to redesign the truss to maximise space. Perhaps more appropriate materials will be used or more of the same material in certain spots. Same goes with having a flat bulkhead vs a cylindrical one on an airline. If you dont know what your doing though, dont. Hire someone that does, this will cost upwards of 100,000 most of the cost being an architect.

But go ahead and start chopping away and let us know how it turns out
 crossfingers 
Nonav.com kinda like Whiners except the lights are on and the pimps been paid
 
jamesbuk
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RE: Help Needed With A Roof Structure!

Sun Sep 10, 2006 8:00 pm

This is a cross section of the actual roof trusses, The black ones are the bars we plan to keep and the red that we'd like to remove.

http://img156.imageshack.us/img156/9374/roofah8.jpg

Rgds --James--
You cant have your cake and eat it... What the hells the point in having it then!!!
 
RichardPrice
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RE: Help Needed With A Roof Structure!

Sun Sep 10, 2006 8:13 pm

Quoting BHMBAGLOCK (Reply 7):
Stick framed roof stuctures are rarely designed by engineers. In the US for example, only FL and CA require this in most cases.

But in every case the design would have been signed off by someone with the knowledge and experience to make that call. I used the term 'engineer' loosely, maybe incorrectly, to describe the person that did this.

Those structures are not just thrown together.

Quoting BHMBAGLOCK (Reply 7):

Actually this can be argued. Most roof stuctures are stick framed when a stronger roof using much less material is possible using trusses.

Are you willing to risk a manslaughter charge on the basis that *maybe* they overbuilt?

Quoting RichPhitzwell (Reply 12):
But go ahead and start chopping away and let us know how it turns out

One of the worst bits of advice Ive ever seen. Hopefully you were joking.
 
bill142
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RE: Help Needed With A Roof Structure!

Sun Sep 10, 2006 9:02 pm

Quoting Jamesbuk (Thread starter):
now we were interested whether its safe to remove the diagonal bars. The ones that run from the bottem middle of the roof up to half way of the roofing diagonal bar, Would this be safe?

NO! thats probably the stupidest thing you could do. They are under quite a bit of compression and removing them will lead to your roof beginning to sag, and possibly collapsing later on. I used to work for a company which built roof trusses and I would go out on site and make repairs/take measurements etc and the guy I worked with said that removing the digaonals is the silliest thing you can do. Apparently alot the the airconditioner installers just cut them out because they have no idea what there doing and ruin the structural integrity of the roof.

Quoting RichardPrice (Reply 14):
But in every case the design would have been signed off by someone with the knowledge and experience to make that call. I used the term 'engineer' loosely, maybe incorrectly, to describe the person that did this.



Quoting BHMBAGLOCK (Reply 7):
Quoting RichardPrice (Reply 1):
1. engineers seldom include structural features that arent necessary.

Stick framed roof stuctures are rarely designed by engineers.

True, but, from memory, the software used incorporates some kind of function warning the designer of possible flaws. It depends on what kind of roofing, be it tile, sheetmetal etc, being used, grade of wood being used, spans etc. However it's not fool proof.
 
fr8mech
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RE: Help Needed With A Roof Structure!

Sun Sep 10, 2006 9:39 pm

Based on the drawing, do not remove the diagonol members.
When seconds count...the police are minutes away.
 
jamesbuk
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RE: Help Needed With A Roof Structure!

Sun Sep 10, 2006 10:46 pm

Ok guys thanks for the help on that.

Rgd s--James--
You cant have your cake and eat it... What the hells the point in having it then!!!
 
RichPhitzwell
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RE: Help Needed With A Roof Structure!

Mon Sep 11, 2006 2:05 am

Quoting RichardPrice (Reply 14):
One of the worst bits of advice Ive ever seen. Hopefully you were joking.

Of course I was joking, hence the statement right above:

Quoting RichPhitzwell (Reply 12):
If you dont know what your doing though, dont.

It is possible to re engineer that roof...you will have a net loss in cubic space but an increase in usable space. An architect will be able to design this if you want to spend the  twocents 
Nonav.com kinda like Whiners except the lights are on and the pimps been paid
 
RichardPrice
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RE: Help Needed With A Roof Structure!

Mon Sep 11, 2006 2:15 am

Quoting RichPhitzwell (Reply 18):
Of course I was joking, hence the statement right above:

Brilliant, sorry if I missed the underlying humour content  Smile No offence meant, just wanted to ensure noone took it out of context and started hacking away...
 
jamesbuk
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RE: Help Needed With A Roof Structure!

Tue Sep 12, 2006 12:36 am

Quoting (Reply 17):
architect will be able to design this if you want to spend the

The thing with this is its not designed to be an extra room or anything its just like a lil thing were we hang out, everything up there is removable so when he moves we strip it out.

Rgds --James--

[Edited 2006-09-11 17:37:17]
You cant have your cake and eat it... What the hells the point in having it then!!!
 
yooyoo
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RE: Help Needed With A Roof Structure!

Tue Sep 12, 2006 12:54 am

i have not read the posts above...... but i would leave all members as is.

A truss is designed to spread the load accordingly. All members play a roll, being in tension compression and all that jazz.

I would advise not to remove them.

Also, the bottom chord of the truss is in all likely-hood not designed to have a live load and or dead load imposed on it. You would need to beef up that part of the truss.

 twocents 

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