Chimneys – Modern Design

Part 6.  The arrival of modern chimneys, and no, it isn’t all good news.

This is a continuation of the article dealing with the chimneys and liners of previous eras.  Starting with the inglenook and the Georgian chimney we have dealt at length with the problems of the Victorian chimneys, because they are many and serious.  As always, should you be concerned that your chimney may be displaying any of these anti-social habits, the best person to discuss it with is your certified chimney sweep.  He will have a good grounding in the subject and is best placed to advise you.

Modern Chimney Design

The 60s.  Peace, love, flowers and a legacy of bad design.  The concept of the modern house, disconnected from the old fashioned fire meant that they forgot the important lessons of chimney design bequeathed to them by the Victorians.

All kidding aside, there was a gap after the banning of the Victorian-style chimneys in 1965 in which the concept of the open fire burning solid fuel was relegated to the past while electricity, gas and oil would provide a modern, sophisticated way of heating the house.

Of course it didn’t work out like that and before too long they were back building solid fuel chimneys, because people dig that stuff man!

Bends in Chimneys

As I say, sadly the old artisans were no longer in work, and the new ones were at a loss to know exactly what they should do.  So, they looked at the old Victorian chimneys and thought “They have bends. Chimneys must have bends!” Because of that we are stuck with so many modern chimneys having bends when bends are a ‘pain in the whatsits’ and completely and utterly useless.

What went wrong?  Well, the problem was that when they looked at the Victorian chimneys, they never thought to ask themselves “Why exactly DO Victorian chimneys have bends?”  Had they had the wit to go up into the bedrooms, they would have seen that the bedroom flues were without exception, vertical, straight and bend-less.  The reason that the downstairs chimney had a bend in them was that the downstairs fireplace was directly beneath the bedroom fireplace and its flue had to bend to go round it.

Just think, because of that, half a century of chimney sweeps, have had to put up with all the problems associated with wrestling a brush around a bend that was less that optimum.

Resolving the Acid Attack Issue

These modern chimneys, as now, were lined with terracotta tubes.  These were acid proof, and so the reason for the failure of so many Victorian chimneys was removed at a stroke.  They did though bring with them a couple of new problems.

Issues with Terracotta Lined Chimneys

The first of these are the ‘snots’.  When the liners are installed, the bottom tube should be fixed in place and backfilled with the female joint uppermost and the male at the bottom (30 years of looking up flues tells me that in reality they are put in at random, as so many times the bottom flue pipe is installed upside down.)  Then, a bead of heat proof sealant is placed around the end of the fixed tube and the next pipe is lowered onto that to make a seal.  Then that pipe is likewise backfilled. There is supposed to be a weighted hessian sack with straw in it that is lowered down and pulled up again to remove the ‘snots’ the bits of sealant that protrude around the joint.  If not removed (and they often aren’t) they cause turbulence and are the very devil to remove.

In addition, a lazy, sloppy builder will slop cement around the joint to the extent that the ‘snots’ drop off and catch on the unnecessary bend.  I have seen someone nearly die from monoxide poisoning from a ball of cement that was almost completely blocking the bend off.

Another problem is when they make the unnecessary bend, but don’t have the special tubes with the bends in them.  So, they hack up a straight tube and put that in.  Invariably this leaves a weak spot where the head of the brush hits, causing even more grief in the sweep’s life.

Apart from that, terracotta lined chimneys are great.

To recap.

  1. Terracotta chimneys are great.
  2. No, really.  They are fine, it’s just that the people who work with them aren’t always up to speed.
  3. Talk to your certified chimney sweep.  If he starts sobbing, make him a cup of tea and be kind to him.  He has seen terrible things, and they play on his mind.


Check out our articles in this Chimney Lining series:

  1. Chimney Lining – Inglenooks
  2. Chimney Lining – Georgian Chimneys
  3. Chimneys and their liners – the Victorian Era
  4. Chimney Lining – Victorian Chimneys
  5. Chimney Lining – Acid Attack
  6. Chimneys – Modern Design
  7. Chimney Liner – Lining a Chimney

For more advice, or to book a chimney sweeping appointment please call us on 01223 964305 or email us at

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Wight Initiatives Ltd,
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Cambridge, CB1 1AH
The Officers’ Mess Business Centre, Royston Road, Duxford, CB22 4QH
Registered in the UK # 7725 203
VAT # 218 3459 04