Concrete Lintel Question

[Tim]

I'm having some building work done on my house. I've just had the old external door and panel removed. What I've noticed is part of the concrete lintel that has the external bricks resting on it, does not sit on the external bricks below. It just kind of hangs there at the front and is only rests on the internal bricks.

I've always wondered how these lintels work. When I look outside at the windows, the visible part of the lintel runs just the width of the window.

Do these lintels require any support from the window or door frames? Or is all their load transferred to the internal wall?

Regards,

Tim

[EricP]

A double wall of modern construction has the brick as a cladding and the internal wall as the actual load bearing one.

A local property had to have all its brick removed and replaced. It looked weird and worrying until explained.

[Tim]

Seems strange, concrete block work seems so fragile compared to bricks. It seems odd that the outer bricks are purely cosmetic (and probably provide a damp proof layer). What strikes me as even more strange is the lintel also takes the weight of the outer brick work and transfers that to the inner block work. Also the way the lintel does it as well must put a strain on the lintel as well.

I must admit I don't know how the forces apply to a building. I heard something about triangular forces. However I would have thought a lintel would at least be supporting all the weight directly above it at the very least.

Regards,

Tim

[AJH]

It's true that the inner leaf blockwork transfers the roof loads to the foundations, but the brick outer leaf is still structural in that it has to support itself and help support the inner leaf laterally. Consequently a door opening in the outer leaf brickwork will need a lintol over to support the brickwork above. It sounds strange that in this case there isn't a lintol so there must be more to it than meets the eye perhaps??

[Tim]

There is a lintel, but it spans the inner and outer courses of bricks. However it's only wide enough at the inner course to be supported. This pretty much means that where there are lintels the weight of the outer course is also transferred to the inner. Strikes me as strange and it's probably been done for cosmetic reasons, even if the lintel is still on show.

Which walls typically take the weight of the roof? I know this is a broad question. But I have a standard 70s 3 bed semi. In the loft there are three beams that run width of the house. One at the apex the other two half way down the slopes. These appear to offer some support to triangular beams/joists that run every 50cm (approx), these go from front to back.

So it's my guess that the entire weight of the roof is on the front and back inner walls. These are the walls with all the doors and windows (that are quite large) and small columns. Not only that but the lintels also transfer the weight of the outer brick work to these inner blocks.

From a layman's view, it appears that all the weight is on the weakest material/walls. Not quite what I was expecting.

Regards,

Tim

[AJH]

Your roof loads are being taken through the inner leaf blockwork, and this has been standard practice for decades so don't worry it's normal. Your lintol sounds a bit strange though, still as long as it all continues to work without signs of stress cracks in the outer brickwork then I would forget about it.

Andrew