custom roof help needed

[Anonymous]

Hi can any help me build a custom roof , i need to create a sloping floor for a theatre and cant for the life of me work it out , any help greatly appreciated.

[Dwight]

Investigate the Complex Profile

Eric Bobrow's fantastic article, yet again

[Anonymous]

Dwight's right (as usual).

Use profiled walls to do the stepping. This allows them to curve (as most theater seating does).

Attached is a screen shot from an early schematic model I happen to be working on right now.

[Erika Epstein]

Matthew,
Very nice model.
What is an SOG?

[Anonymous]

Erika wrote:
Matthew,
Very nice model.
What is an SOG?

Thanks. Of course it's very preliminary. It'll be much better when SD is finished in a couple of weeks.

SOG = slab on grade

[Dwight]

Matthew wrote:

Erika wrote:
Matthew,
Very nice model.
What is an SOG?

Thanks. Of course it's very preliminary. It'll be much better when SD is finished in a couple of weeks.

SOG = slab on grade

SOG = Sonovagitch

[Anonymous]

Hello Matthew,
I am curious about something.
In your image you call out a sloped SOG.
I wonder how steep a slope is practical
for concrete work. I have not sloped form work
more than maybe five degrees and wonder
how steep the form work can be before the concrete
just keeps slumping and cannot be held in place
until it kicks off. I am contemplating a sloped frost wall
with a sloped top surface and wonder how much of a slope
I can get away with.
Thanks,
Peter Devlin

[Gerald Hoffman]

Peter, I have done a sloped conc roof slab at 6/12 pitch. The crew managed to pour it OK. I am not sure what special techniques they used if any. Picture is too big to post so here is a link. There are 2 pictures there and in one of them I have put a light oval around the sloped slab in case you couldn't find it.

http://picasaweb.google.ca/lh/sredir?uname=gerald.hoffman&target=PHOTO&id=5496842324775204370&aid=54...

Cheers,

[Anonymous]

Hello Gerald,
Thanks for posting back.
A 6 in 12 pitch is fairly steep considering
that water and concrete flow down hill.
I'm sure the crew had to use some special
techniques. Why did you think this was possible
and thus specified this in the plans ?
Thanks,
Peter Devlin

[Gerald Hoffman]

Peter,

I had actually specified this to be framed with wood but the Structural Eng wouldn't go for it in this area so it got changed to concrete. I had seen concrete applied to the top of CMU gable end walls in the Caribbean. They top off the wall with concrete to fill in the notches along the top of the staggered blocks as well as an additional 8" deep bond beam above that all sloped. Some of the roofs were at least 9/12 or so so I just assumed it would be OK for my 6/12 roof.

Maybe its better sometimes when you don't know if it can be done or not. It worked out OK. I could ask the crew what they did if you would like the information.