Why Your ‘Original’ Fireplace Opening ISN’T What You Thought It Was…

For those looking for a cheap and quick way of having a real fireplace at home, it’s a common mistake.

After a few hours sweating with a hammer and chisel, there infront of you is your ‘original’ builders’ opening.

So you might think: “Great, all I need now is a fire basket and I’m set!”

Actually, it really isn’t. Because chances are that, far from being set, the only thing you’re likely to set off is your smoke alarm!

See, the term ‘original’ opening can be quite misleading. Because in 99.9% of properties, they were never actually used as fireplaces in the way most assume.

The openings were just that – openings to put actual fireplace surrounds in.

The majority of homes we live in today were constructed with these openings as they were large to accommodate range cookers, as pictured below.

If you study the photo, you will see ‘fireplace’ grate part on these ranges were comparatively small so they worked.

Over the years, fireplaces became smaller and smaller in decorative size, so the gap between the original opening and the fire surround were bricked in, as you can see in the picture below.

If you look carefully, you will see the original opening and the arched lintel. This has been bricked in to accommodate a much smaller open fire..

Consequently, the size of ‘original’ openings started getting smaller, especially when range cookers fell out of use.

So as you can see, the idea that original openings were used with just a solitary fire grate/basket in the middle is a complete misapprehension.

But why do so many think this – there must be a reason surely?

Well, some of it is myth. And some of it usually comes from the fact that some much, much older properties, such as National Trust properties, DID have large openings.

However, these usually had bigger flues, much more ventilation and of course there is no guarantee they worked in a way we would consider acceptable today.

For example, on many occasions, smoke would spill into the room. But this would not concern the Lord of the Manor as he would be sat in an enclosed chair which would shield him from the fumes.

In many cases, ventilation wasn’t an issue as these big halls were draughty places, and in some cases didn’t have even have glass in the windows.

They were massively inefficient and, by modern standards, quite dangerous.

Even by the 1700s, it was enough of an issue to prompt the creation of smaller fireplace designs, especially ones which would reflect more heat into the room rather than losing it up the chimney.

In some pubs, you may find the odd inglenook open fireplace as well. However these have mostly been modified over years with canopies and even an electrical chimney fan to make it the fireplace work.

So why won’t a large opening work?

Put simply there is a bit of maths and science at play.

It goes something like this: the bigger the size of an opening, the bigger the flue and ventilation needed in order for an open fire to work properly. There’s a whole bunch of calculations which need to take place.

Many homes built in the last few hundred years simply don’t have the size of flues and ventilation capable of serving a large opening.

Even if it took some of the smoke away, we simply wouldn’t accept fumes spilling into the room in a way people hundreds of years ago would.

In more modern homes, this would present a carbon monoxide risk and shouldn’t even be attempted.

Of course, these days original openings are being exposed to install woodburners and multi fuel stoves instead of range cookers.

But the smoke is ‘funnelled’ into the flue from the fire itself via a pipe, so it works.

So even if you do have a large opening, you can have a real fireplace, but just not the one you probably thought initially.

Because, despite the myth, they were never ever intended to be used as open fireplaces…

Mr Soot Chimney Sweep is a HETAS Approved Sweep, and member of the Guild of Master Chimney Sweeps, offering a professional and friendly chimney sweep and stove service. Book Mr Soot online or call 07724 311 992.

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