Concrete lintel foundation in footings

[wessex101]

I'm amazed that BC are actually approving of this method. I'll stick to the old way of putting in a foundation when I do mine.

Are concrete lintels approved for use below DPC, potentially saturated wet? I'd worry the reinforcement would corrode and blow apart.

Plus it puts a fairly hefty load on two unconnected wall ends.

When you see the cracking and spalling that can occur on exposed concrete lintels above door and window openings in relatively dry conditions it does make the idea of burying a standard precast concrete lintel underground with quite wide spans seem rather bonkers.
I would not specify it unless the house is on very deep or special foundations making digging out a new foundation impractical and only then a properly designed ground beam with plenty of cover to the reinforcement.

 

[^woody^]

I'm amazed that BC are actually approving of this method

Do you mean still approving it? Like, since forever?

How does your exploding RC lintol theory translate to other reinforced foundations .... and rafts, and basements and high-rise columns, dams and ... well everything else reinforced in the ground?

And likewise for load transfer, how is it any different from a lintel above ground. Apart from probably a bit more gravity being it nearer the earth's core.

 

[^woody^]

BTW, there are actually LABC approved details on using lintels and steel beams in the ground.

Everyday's a school day

 

[Ivor Windybottom]

Rebar is used in road bridges. But they go to extreme care to ensure the road surface is sealed to ensure that water doesn't get into the concrete below. I know of one 1960s flyover where they embedded heating elements so they could avoid the need to spray salt onto the road.

I've recently put rebar mesh into a concrete paved area. But it's only really there to stitch it together and prevent cracking and perhaps sinking over minor dips in what's underneath, I'm not relying on its strength to span any large gap.

Obviously all lintels concentrate loads onto points. But usually a couple of metres above the foundation, so it gets spread by the brickwork across a few metres of foundation. But putting the load directly onto two end points is a lot more focussed. It would be bad enough if it was a mid-point, but right on an end seems like a recipe for trouble.

It will have a lifespan, probably beyond the lifetime of the person who's building and approving it. It's not going to suddenly explode one day, but you may get movement and cracking as it gradually twists and sinks.

I can understand the attraction of it being a quick and cheap way of doing it. It will last beyond the payment clearing and probably beyond any warranty period. But on my own home I'll be getting the spade out.

 

[wessex101]

BTW, there are actually LABC approved details on using lintels and steel beams in the ground.

Everyday's a school day

That would be the same LABC that signed off Grenfell Tower and hundreds of other high rise buildings covered with flammable cladding? Hardly a ringing endorsement of their professionalism and competency.