No fireplace lintle? Curious...

[Tim S]

I've just uncovered the brickwork on a fireplace, and unlike the other fireplace, this one does not appear to have a lintel.

Sorry - no photos yet.

What we have is a 2' or so opening, a soldier course of bricks over the opening, then the next course above is normal brick. I haven't uncovered more yet, but am curious. Is this normal?

It is clearly as it was when the house was built and it hasn't fallen down in 50-60 years so it's obviously up to the job.

But I'm not sure how it works... It is a case of the soldier course only needing to support the triangle of brick above?

Cheers

Tim

[Bob Mannix]

In such cases there is usually a steel bar up under the soldier course built in either end, which gives support.

[dent]

I found exactly the same thing when I fitted a woodburner last winter. I discovered that where the chimney narrows from the fireplace's main opening to the smaller dimension of the chimney, the whole of that section was one big concrete block which acted as a lintel for the opening, as well as supporting the chimney. The courses of brick that reduced the opening didn't have any extra support to keep them up. To avoid future problems, I took the bricks out, and rebuilt it with thermalite blocks sitting on a metal lintel just above my new inset woodburner.

dan.

[NT]

If you press down on a soldier course, it tries to spread sideways. But the weight of bricks over the ends prevent that happening. So it acts like a lintel. And yes, brickwork interlocks so the soldier course only supports a small area of brickwork.

NT

[Tim S]

Bob Mannix wibbled:

Aye - that's what I thought. Can't find one though...

Nor up the back side - had a good rummage up there with my hand...

Unless there's some bar in the next course up, I see no steel at all.

I have some heavy bar I can insert under and key in both ends... BCO's coming on Friday anyway, so I'll run it by him too.

Cheers

Tim

[Tim S]

NT wibbled:

I guess it must be working like that - because works it does (no cracks) - but it's not consistent as another fireplace in teh house does have a lump of concrete over the opening...

Cheers

Tim

[Tim S]

dent wibbled:

Interesting - I haven't uncovered the brickwork that far up - perhaps mine does the same...

I've got a steel bar to wedge under the soldier course just in case (I worry I might loosen stuff with all the banging that going on in that area).

Ta

Tim

[Hugo Nebula]

On Tue, 30 Jun 2009 21:25:49 +0100, a certain chimpanzee, Tim S randomly hit a keyboard and produced:

Is it horizontal or an arch? If the latter, then it is self-supporting.

[Tim S]

Hugo Nebula wibbled:

It's the former. I was looking really carefully to see if it was one of those almost flat arches, but it appears to be a dead horizontal soldier course.

Cheers

Tim

[Hugo Nebula]

On Wed, 01 Jul 2009 19:11:59 +0100, a certain chimpanzee, Tim S randomly hit a keyboard and produced:

I suppose it may be supported by the force of the walls either side. Try holding a number of books horizontally between your hands. You can do it if you press hard enough.

[The Natural Philosopher]

If its even mildly arched, it will work without steel. In fact, even if its not, its not bad. Think of taking a string of sugar lumps, and putting them in a line and squeezing each end..it takes quite a load before collapsing. . The walls provide lateral resistance to spreading, which the soldier course must do before it buckles.

[The Natural Philosopher]

Now think about removing an arch shaped section from the bottom of the course..Voila! You have an arch as deep as the soldier course is! (largely).

Now you see WHY a soldier course is used.It has the properties of an arch as deep as the course, with the proviso that its slightly compromised by the all-vertical mortar joints, and can fail by a brick sliding past another, so it wont work as a dry stone structure, which a true arch will, if done right. And its compromised by weak mortar too. If one brick falls out, its not good.