In message , Mara
writes
Hi,
what reinforcing method should be used to bridge a 5.5 ft wide 4.5 ft high
opening through a ground floor, concrete block, load-bearing wall in a 2
storey building which has a concrete ceiling/floor between the two levels?
Our current builder has installed a reinforced concrete lintel turned on its
side with approximately 6 inches of lintel beyond the opening on either
side, but another builder has just told us that this is not sufficient
support and should be replaced as it is potentially dangerous. Who do we
believe?? and if this is wrong, what is best to use for the job??
Thanks in advance
Mara


A reinforced concrete lintel will typically have a proper orientation.
(ie "this way up"). The structure of the reinforcing requires it.
Basically the steels in the bottom of the beam are under tension while
the concrete at the top of the beam is under compression.

Turning the lintel on its side would result in little or no reinforcing
of the concrete.

Have a look here, about half way down, left hand side, for a sketch.

http://www.nottingham.ac.uk/sbe/proj...orralweb/wcons
truction%20courseworkp5.htm

Hth
Someone