bajadaze
Junior Nomad
Posts: 43
Registered: 3-10-2011
Location: Punta Chivato
Member Is Offline
|
|
concrete pila roofs
Building a shed 10x20x8' high. never built a concrete roof but would like to over hang 2 feet on three sides. I'm a builder without this experience.
Can someone tell me the layout of 3/8 rebar to get the job done. 3.5" thick.
|
|
|
4x4abc
Ultra Nomad
Posts: 4290
Registered: 4-24-2009
Location: La Paz, BCS
Member Is Offline
Mood: happy - always
|
|
that is too easy
Harald Pietschmann
|
|
|
larryC
Super Nomad
Posts: 1495
Registered: 8-11-2008
Location: BoLA
Member Is Online
|
|
I've never done one either but my father had a block garage built at his place at Cabo Pulmo and as I remember there was lots of rebar like 1/2" on 4
or 6" centers criss crossed. I did a garage some years ago here in BoLA, a 75' x 25' and framed the roof and then put metal laminate on it I'm sure
the roof will outlive me and that's all I care about. If you are in an area where there are lots of subterranean termites then you might want to use
treated lumber. If you do a concrete roof you won't have to worry about termites so there is something to be said for going the extra mile.
Off grid, 12-190 watt evergreen solar panels on solar trackers, 2-3648 stacked Outback inverters, 610ah LiFePo4 48v battery bank, FM 60 and MX60
Outback charge controllers, X-240 Outback transformer for 240v from inverters, 6500 watt Kubota diesel generator.
|
|
|
StuckSucks
Super Nomad
Posts: 2325
Registered: 10-17-2013
Member Is Offline
|
|
If there was only a way to figure this stuff out.
Calculate Rebar Spacing, Layout and Weight in a Concrete Slab
|
|
|
mtgoat666
Select Nomad
Posts: 18392
Registered: 9-16-2006
Location: San Diego
Member Is Offline
Mood: Hot n spicy
|
|
That calculator is for a slab.
The op wants to build a concrete roof with 20 ft span.
Woke!
“...ask not what your country can do for you – ask what you can do for your country.” “My fellow citizens of the world: ask not what America
will do for you, but what together we can do for the freedom of man.”
Prefered gender pronoun: the royal we
|
|
|
Timo1
Senior Nomad
Posts: 743
Registered: 11-2-2007
Location: Homeless
Member Is Offline
Mood: Lovin every minute of it
|
|
Just get a good local mason to do it
Simple we did
sold out and got out !!!
|
|
|
BajaTed
Senior Nomad
Posts: 859
Registered: 5-2-2010
Location: Bajamar
Member Is Offline
|
|
Suggest a 15 degree roof pitch for your shed.
20' - 6"x6" rebar beam with single center post support for the concrete roof
Es Todo Bueno
|
|
|
BajaUtah
Nomad
Posts: 190
Registered: 10-4-2013
Location: Salt Lake City/La Ribera
Member Is Offline
|
|
We did 30"x12" foam block and 8"x12" 1/2" rebar beam. Open garage space is 40' x 20'. Admittedly my contractor loves to over build but made it through
Odile and Lorena here in La Ribera easy peasy.
[Edited on 10-30-2019 by BajaNomad]
Andy
|
|
|
4x4abc
Ultra Nomad
Posts: 4290
Registered: 4-24-2009
Location: La Paz, BCS
Member Is Offline
Mood: happy - always
|
|
since the slab rebar is not embedded in the concrete it serves no function
but the predictable corrosion won't weaken the bunker since the beams will last 1,000 years (IF the concrete has been vibrated correctly)
Harald Pietschmann
|
|
|
mtgoat666
Select Nomad
Posts: 18392
Registered: 9-16-2006
Location: San Diego
Member Is Offline
Mood: Hot n spicy
|
|
Quote: Originally posted by 4x4abc  | since the slab rebar is not embedded in the concrete it serves no function
but the predictable corrosion won't weaken the bunker since the beams will last 1,000 years (IF the concrete has been vibrated correctly)
|
rebar should have been in center of concrete, and at least 2 inches from edge of pour.
concrete needs to be a correctly mixed and properly cured to last.
bad mix or bad cure and concrete will not achieve adequate strength
Woke!
“...ask not what your country can do for you – ask what you can do for your country.” “My fellow citizens of the world: ask not what America
will do for you, but what together we can do for the freedom of man.”
Prefered gender pronoun: the royal we
|
|
|
Timo1
Senior Nomad
Posts: 743
Registered: 11-2-2007
Location: Homeless
Member Is Offline
Mood: Lovin every minute of it
|
|
Goat
You are just a wealth of knowledge
sold out and got out !!!
|
|
|
4x4abc
Ultra Nomad
Posts: 4290
Registered: 4-24-2009
Location: La Paz, BCS
Member Is Offline
Mood: happy - always
|
|
the center is the last place where you want the rebar
rebar is either at the bottom or at the top - sometimes both
depends on where the stress will occur
any decent engineer can provide a simple plan for that
remember, concrete can absorb a lot of pressure
but it will not withstand pulling or shearing forces
the embedded steel will absorb those forces
together they are a strong team
IF the rebar is placed where those forces occur
Harald Pietschmann
|
|
|
4x4abc
Ultra Nomad
Posts: 4290
Registered: 4-24-2009
Location: La Paz, BCS
Member Is Offline
Mood: happy - always
|
|
if the rebar would be placed at the center of a roof slab, the tension forces would not be absorbed - only bars at the bottom can do that (in this
simple example)
Harald Pietschmann
|
|
|
![[*]](images/xmbforum/default_icon.gif){kind=icon}
