Sewer pipes to go though foundations, protected by concrete lintel.
What depth in the foundations does the lintel go - replacing first row
of bricks / embedded in
trench, or what ?
Also, how is the size of the lintel calculated.
Thanks,
Simon.

On 23 Nov 2005 02:29:08 -0800, a particular chimpanzee named
randomly hit the keyboard and produced:

Sewer pipes to go though foundations, protected by concrete lintel.
What depth in the foundations does the lintel go - replacing first row
of bricks / embedded in
trench, or what ?
Also, how is the size of the lintel calculated.

The drains shouldn't go through the concrete foundations (actually,
they can, but you'd need rocker sections either side). They should go
through the wall. If the drain is low relative to the foundation then
you should step the foundation below the drain. The steps should be
at least twice as long as the thickness of the concrete. The lintels
are bog-standard 150x100mm precast concrete lintels - no calcs needed.

_________________________________________
_________________________________________ Wall
___________| Lintel |_____________
___________|_______________|_____________
______________| |________________
______________| O |________________ _
|___|_________|____| /\
T Concrete
____ _____ \/
|_____________________________|
| 2xT |
--
Hugo Nebula
"If no-one on the internet wants a piece of this,
just how far from the pack have you strayed?"

The drains shouldn't go through the concrete foundations (actually,
they can, but you'd need rocker sections either side). They should go
through the wall. If the drain is low relative to the foundation then
you should step the foundation below the drain. The steps should be
at least twice as long as the thickness of the concrete. The lintels
are bog-standard 150x100mm precast concrete lintels - no calcs needed.
Thanks for that. This is in an area where the foundations must be 2
metres due to
near public sewer that has 2m invert. I think the pipe will be over 1
metre down.
That would be a lot of brickwork over the top. Wouldn't you have the
foundations up either side of the pipe and a lintel across concrete the
concrete "walls" either side ?
Otherwise, the lintel would be supported on the underground blockwork,
which would be hard to construct one metre down. Also, what is a
"rocker section" ?
Lots of questions I know.
Thanks,
Simon.

On 25 Nov 2005 02:29:04 -0800, a particular chimpanzee named
randomly hit the keyboard and produced:

I think the pipe will be over 1 metre down.
That would be a lot of brickwork over the top. Wouldn't you have the
foundations up either side of the pipe and a lintel across concrete the
concrete "walls" either side ?
Otherwise, the lintel would be supported on the underground blockwork,
which would be hard to construct one metre down. Also, what is a
"rocker section" ?

Right. If you're trench filling your foundations, the drain is a
100mm diameter one passing at right angles through the footing and the
thickness of concrete over is substantial enough, you can probably do
away with the lintels. Roughly speaking, if you can take 45° lines
from the edges of the 'hole' for the drain and they intersect below
the upper surface, the loads should be adequately distributed to
prevent the foundation cracking.

Otherwise, shutter the drain with some compressible material (mineral
wool batts) and cast some reinforcement bars into the concrete above
the drain (two or three 8mm dia bars about 1m long) with 50mm cover
under.

A rocker section:
http://www.odpm.gov.uk/embedded_object.asp?id=1132107
--
Hugo Nebula
"If no-one on the internet wants a piece of this,
just how far from the pack have you strayed?"