Unblocking a chimney

[ireneadler101]

We are buying a Victorian house which has had its fireplaces blocked up. It looks as though they have been plastered over and we are keen to reinstate them. Can anyone suggest the best way of unblocking these to see what's underneath? Is this a DIY job, or a job for a builder? I am aware that once unblocked, the chimney will need to be swept and inspected, and potentially lined.

Presumably you guess where the opening would be, and chip away to see what's behind the plaster? Either it could just have been boarded over and plastered, with the fireplace intact, or it could have been bricked up?

Sorry to ask such an obvious question but we are new to renovating and need all the help we can get! I am dying to get cracking and see what's behind the wall, but don't want to risk any damage, either structurally or to any potential fireplace behind the wall...

 

[Feltwell]

Welcome to PPUK, and don't worry about asking "obvious" questions, there is no such thing when you first start!

Are all the chimney breasts still in place, or have any been removed? If so, completely removed or only taken out of certain rooms? Are all the external stacks above the roofline still there? Presuming all the chimney pots are still in place, can you work out from each stack where all the fireplaces that fed it were, there should be 1 per pot? Don't forget that a kitchen range and a wash house copper may also have had their own flues.

Unblocking fireplaces internally is (usually!) an easy DIY job, it's the lining and any external works that are more involved if you want it to be a working fireplace.

Firstly, where the opening should be, tap it with your knuckle - if it's board that's been plastered over it will sound very hollow, if it's brick it will sound solid.

Taking the decoration off should reveal where the opening was, unless the whole face of the chimney breast was skimmed with plaster. If that's the case, just start at the bottom in the middle, and take plaster off horizontally until you see where the bricks change, then start going up until you reveal either a brick arch or a big lump of metal - the lintel - this is what supports the chimney breast above. Before you take any bricks out, make sure the arch or lintel is there and looks OK - very rare that they've been touched. Don't worry, taking the plaster off won't do anything other than making a mess! Just take your time and keep chipping away slowly with a small lump hammer and a cold chisel, no power tools.

If the current chimney breasts are flush faced with no obvious boxing hiding a fireplace, then what you will reveal in all likelihood is just the "builders opening", i.e. the space into which the original fireplace was inserted. This, including the brick arch, was never meant to be seen.

For a cosmetic, non-working fireplace you can simply get the surround & insert of your choosing and fit it in place. It's a good idea to get the flue swept by a chimney sweep - old soot reacts with moisture over time to form an acid which eats into brickwork and pointing - then make sure there is still some ventilation to the old flue, don't block it up. On the outside, you should cap the chimney pot off if it's not already been done - again ensuring ventilation. A popular way to do this is a "pepperpot" insert, a round cap with holes in the side that sits in the top of your original chimney pot.

For a working fireplace it's a bit more involved and I would strongly recommend getting a HETAS registered fitter to do the work for you - carbon monoxide is not to be messed with. A "living flame" gas fire must have the flue lined, as must a solid fuel stove (different sort of liner though), an open solid fuel fire doesn't necessarily have to be lined depending on the condition of the flue - but I'd play safe and get it done anyway personally, after 100+ years of fires I don't like to trust that the original flue is still gas tight.

An open fire will be more original and will look lovely, but will be very inefficient. A stove is a lot more efficient and better at actually heating the room. The choice is yours!

Have you any original fireplaces, or have neighbouring houses? It's a long, painful process but if you search you may be able to find fireplaces that are the same as what was there originally, I've managed to by steadily buying up various, often incomplete, matching fireplaces and building complete ones from the parts. It takes patience though and a willingness to travel! Go through the cellar and any outhouses, check any undergrowth in the garden, you may find bits of the original ones, I did!

Lastly - take your time before making any changes. Don't be too enthusiastic with that hammer, one room at a time! You may have more urgent priorities on a new house than sorting out fireplaces.

Ohh yes, and everyone on here loves pictures. :wink:

 

[livias]

Good summary Feltwell
Remember that opening up fireplaces is the messiest job that there is. Soot is FINE and BLACK and GREASY so try to work in an empty room and pass bags of waste out of the window

 

[Flyfisher]

Yes, good summary and agrees with my limited experience of opening up two chimneys.

I'd just add that if the pot is not covered then be prepared for the chimney to be full of debris. One of our chimneys had clearly been playing host to nesting birds over many years, judging from the amount of sticks and skeletons removed. A hook attachment on the end of drain rods was essential for snagging the twigs to pull them down - not a particularly difficult job but very messy, as livias has rightly pointed out!

 

[angrybird]

Good summary Feltwell
Remember that opening up fireplaces is the messiest job that there is. Soot is FINE and BLACK and GREASY so try to work in an empty room and pass bags of waste out of the window

not forgetting the bird poo and bat guano! I had 5 bin bags of it from one chimney! A mask is a must or it will singe the hairs from up your nostrils :lol:

 

[Tony.]

We don't call them pepper pots but call them elephant's foot


Don't see too many upside down elephants but you get the idea

http://www.1stsuppliesscot.co.uk/chimney-cowls-caps-pots/1305-fluvent-elephants-foot-buff.html

 

[plasticpigeon]

It shouldn't be too bad. I would imagine that the openings have been bricked up. There will be a builders opening that is far larger than the original insert, perhaps 5 ft high, and as Feltwell says it will be an arch (most likely) or perhaps have a lintel. Originally within this large opening, there would have been more brickwork that would have been built to fit the insert that was put in. The best idea is to knock the plaster off and see what you've got!

 

[Lewis Tiffany]

Found the best way is to remove one brick from the bottom first and work your way in
If you remove the plaster first this will show the opening

Be prepared for a lot of soot and rubble especially on
ground floor fireplaces some are used to disposal of rubbish
This one was cleaned out because of the damp coming through wall because it had been filled with rubble you can see the damp about 2ft up

Seven and half bags of soot and rubble from a first floor fireplace.

The photo up the flue shows damp towards to the top of the stack dark area this is because of the missing pointing .

 

[ireneadler101]

Thanks very much everyone - that has given me the confidence to give it a go - even if I only get so far as to chip away at the plaster!

 

[ireneadler101]

So we have finally moved in and I've given the fireplace a go...

It's not revealed quite what I expected, though..no bricks, just cement mortar under the plaster. Do I just keep chipping away until I get to brick? Obviously any lintel is currently covered up (assuming it wasn't removed). Has anyone else dealt with something like this? If so, any suggestions or techniques? It's looking like it will be a long slog as it's rock hard...I'm also worried about chipping too much away without identifying the lintel...

 

[MikeG]

I'm not sure what you mean by "no bricks". The bricks are clear to see in that photo. Just keep chipping away. Once you have one or two bricks out, there rest should follow fairly easily.

 

[ireneadler101]

The photo is misleading - although it looks like the outline of bricks, there is just thick cement mortar which we've not managed to break through. Drilling into it doesn't bring out any brick dust either. I will persevere though in case I'm wrong!

 

[stuart45]

Could be concrete blocks with a sand/cement render.

 

[MikeG]

It doesn't matter what they are, get them out! Oh, and take that skirting board off (carefully) before you go any further.

 

[ireneadler101]

Thanks - we will try to remove the skirting as I agree that will assist - there is definitely a gap under there and there is quite a draught coming through so fingers crossed it will make chiselling away the cement a bit easier. Any tips on how best to remove the skirting without splitting it (can you tell we are novices to restoration?!)?

I am half tempted to get the Feinn multimaster out and cut out the section of skirting in front of the fireplace and lever just that section off. Suspect there will be a fair few nails holding it in which will make it tricky though...

 

[kreyszig]

Fein + crowbar would be my approach (for the skirting)

 

[Flyfisher]

Removing the first brick or block is always the most difficult part, after that there will be an 'edge' to work against. When a few bricks or blocks are exposed through the render, it might be worth drilling some holes through the mortar around one of them. That should help loosen the brick for easier removal. Hopefully the mortar will not be some horrible hard mix. I've been fortunate in that the fireplaces I've opened up have been filled with a very weak lime mix and once the first brick had been removed the others could be pretty much removed by hand with only the occasional assistance of a small crowbar.

 

[Zebra]

not forgetting the bird poo and bat guano!...A mask is a must or it will singe the hairs from up your nostrils

Hmm, perhaps a useful grooming tip there for the older gentleman.

 

[ireneadler101]

Slow progress here - after hacking away at the edge of the cement mortar, this is what I've found so far. Red brick can clearly be seen under there. I suspect this is the original brick wall next to the fireplace opening, but we shall see...

...there also seems to be some some wood in there...strange.

 

[ireneadler101]

Progress:

Would you feel happy removing the brick infill, given that there seems to be a metal lintel remaining?