Advice on tidying up opened fireplace

[Spoilt Victorian Child]

Our fireplace was bricked up by the previous owner. I've removed the majority of their handy work, but annoying they tied in their modern bricks to the existing coursework on the left and right front edges, so the two sides have a mess of chopped off modern bricks, smashed originals and cement filler.

I'm now contemplating whether to try and remove these odds and ends, put some reclaimed bricks back in and then repoint it all. (I have no experience in any of this whatsoever.)

Here's the current state of it:

The fireplace will be used for storage or display items, and I'm hoping the finished result will look like this (but without a mantle or wood burner):

Do you think this is achievable for a novice?

If so what sort of lime mortar should I use? The existing mortar is very light in colour (under the soot), with small stones in it (you can see them in 2nd pic).
Some of the existing mortar is still sound, but some of it crumbles easily when you rake it with a screwdriver.

 

[Easrow]

It's doable. We have been doing ours and has been coming out well. We did it to repair though and won't be on display as one has a cast iron insert and the other will be rendered. Obviously you will need to be careful as it is structural and holds a lot of weight up but ours were stable and nothing moved. We used nhl 3.5 with yellow sharp sand to a ratio of 3:1. (3 sand, 1 lime) It's quite hard getting the old bricks out. We used a lump hammer and chisel and found sometimes it's easier to smash the brick up than try to dig mortar out and damage decent ones around it. Fitting bricks in between others is a right pain as it's tight on space around it but put some mortar in the (wetted) hole at the back and some on the lower part. Then put some on top of the (wetted) brick and slide it in. Some will get pushed to the back and some will slide off the top, you may need to try a few times to get it sitting right. Then push in mortar around the rest of the brick and back it nice and tight. Be as neat as possible but don't worry too much about getting it on the brick as it can be taken off with a wire brush (cheating) after leaving to set for a while. Good luck

 

[livias]

I did much the same to one of my fireplaces. The bricks on the leading edge are one third or a half fake. You can just see that because the colour is not quite right so one day I shall go back and darken them up a bit



View attachment 1

I used chalk/lime putty/synthetic hair mortar which is very mouldable to get the 3D effect you can see in the last picture. For your fireplace, I would then have some sand and small stones to throw at it to get the right surface texture. Once it is set, then paint artistically with burnt umber and soot to get the truly rustic look

I don't see why you can't do it, there is plenty of working time with lime putty mortar and in truth the more rustic it looks the better.
Follow the usual rules of damp down well beforehand and make sure there is gentle heat (not likely to be a problem) and some airflow (you might want to put a fan nearby) . Ask if you have any questions

 

[Flyfisher]

We went from this . . .



. . . through this . . .



. . . to this . . .



We lime-plastered the two side pillars as shown because the bricks were badly spalled/broken (the replacements can be seen in the 2nd photo) but didn't do anything to the remainder of the brickwork except give it a good scrub with a stiff, dry handbrush to remove all the loose pointing and most of the soot. It's not perfect by any means but we were concerned it might look too new if it was re-pointed. It certainly didn't take long to learn to live with it and it's a nice thought that the last person to do any work on those bricks was the original builder a few hundred years ago.

 

[Cubist]

Hi There,

It's all seems perfectly doable to me but there are some considerations/questions that come to mind. The first being whether the the bodger that did the work has left sufficient support under the lintel? Also, what material is the lintel made from and what condition is it in? In my opinion you need to check these out before going anywhere near it with a hammer and chisel to remove the unwanted modern bricks and cement mortar. In any event I would recommend propping the lintel with suitable jacks before starting to remove any 'structural' material. Another consideration would be whether the chimney/flue has been properly blocked to prevent rainwater entry and whether that too is in good condition. Also, you may want to consider whether, and how, to block the chimney just above lintel.

It should be easy enough to get hold of similar bricks to the old ones in the fireplace and with some practice you can learn to cut them with a bolster chisel to the required size without destroying them; but you could also hire a suitable powered cutter. Ty Mawr, among others, provide a wide range of pre-mixed pointing and building mortars you can use to lay the replacement bricks and also to re-point the existing brickwork to get a good clean finish.

Lastly, do not be tempted to use a sandblaster to clean the soot and other dirt off - that would strip the face of the bricks and leave a horrendous finish. A good wire brush, patience and elbow grease and a tool to root out the mortar between the brick joints - but only to maximum depth of 20mm - will be all that you need.

Hope this helps and good luck,
Cubist

 

[Spoilt Victorian Child]

Thanks for all the replies and pics, very encouraging to see so many people have done similar.

@Easrow - ahh so sharp sand comes in different colours? I assume I'll need white. When you say 3:1 sand & lime, what sort of lime - like the lime putty Livias suggested? It won't be hard getting these old bricks out, even the good mortar breaks down quite easily.

@livias - what do you mean your bricks are 'one third fake'? Are they more like brick slips? Looks good.

@Flyfisher - wow, cool find behind innocent looking alteration!

@Cubist - there is an original iron arched lintel about 2-3 courses above where I've opened it up to. The few modern bricks still 'floating' below the lintel are bonded together with cement, and have a really hard cement plaster on top. I opened it up over a year ago and they haven't moved, so don't think they will do so, but will prop them as a precaution while working, thanks.

Will check out the Ty Mawr pre-mixed mortars - thank you!

I'm still unsure how to block the chimney up at the bottom to stop further soot falling down, was thinking maybe batton all around about 1 course up inside the chimney, and screw a sheet of marine ply to the batton, possibly with a vent in it?


I've watched all the videos I can on repointing in both lime and cement, and repointing with lime seems a lot easier/more forgiving - am I right?
Have you guys seen this guy: https://www.youtube.com/watch?v=vG5ZZPu7rCA (he starts at 10:06) - is his technique a good example to be aiming towards?

 

[paulc]

When you say 3:1 sand & lime, what sort of lime - like the lime putty Livias suggested?

Lime putty will do just fine. Mix slightly damp sand in to the putty and add a tiny amount of water if required, If you add too much water, leave it to stand for a few days/months and the excess water will come to the surface. With lime putty mixes, as long as you keep it damp in a sealed bucket, the stuff will last for years.

One other tip - Soak your replacement brick overnight in a bucket of water and then leave them to drain for an hour or so before you come to use them. Give the old bricks a good soaking as well. If everything is dry, the bricks will suck all the moisture out of the mortar causing it to crack.

 

[Abi Cott]

I'm still unsure how to block the chimney up at the bottom to stop further soot falling down, was thinking maybe batton all around about 1 course up inside the chimney, and screw a sheet of marine ply to the batton, possibly with a vent in it

Stoves get hot. Very hot. Heat rises. Ply is a bad idea. I've not got a stove yet so I've not researched this properly, but some sort of cement board would be more my thought. For the amount you need it would probably not be dissimilar in price. A sheet of cement aquapanel might do the trick.

 

[paulc]

The fireplace will be used for storage or display items, and I'm hoping the finished result will look like this (but without a mantle or wood burner):

No stove, so ply would be just fine. A small grill in the middle will help with ventilation, although I would put a baffle plate over the top to stop any soot falling through.

 

[livias]

Mine is all modelled in chalk lime plaster. You only need to remove enough of the new stuff to get space for a 10mm layer of plaster then get modelling ☺

 

[Cubist]

I'm still unsure how to block the chimney up at the bottom to stop further soot falling down, was thinking maybe batton all around about 1 course up inside the chimney, and screw a sheet of marine ply to the batton, possibly with a vent in it?

That would work and a vent would ensure the brickwork above and below would still be able to breathe. However, there would be some heat loss from the room and hence a draught. An alternative you might want to consider would be a Chimney Sheep, they are available on-line for £20-£40 depending on shape and size, also they appear to be very easy to install/remove.

Here's an example on Amazon.

https://www.google.com/aclk?sa=L&ai=DChcSEwjNwaWm4tDeAhXqk-0KHXoFC10YABAPGgJkZw&sig=AOD64_3S315NkoNnT5xwyFxgIm75pAvb7Q&ctype=5&q=&ved=0ahUKEwi116Cm4tDeAhXRN8AKHQobCEAQ9aACCEo&adurl=

 

[Easrow]

A quick reply to your question. Yes sharp sand comes in different colours. Even the same sand can have different colours due to being done in batches. Once the lime is added it will go quite light so you might find yellowsharp sand is fine. We use natural hydraulic lime. (NHL) which comes in different strength. The NHL 3.5 is middle and easier to get hold of at our building supplies. We
've not used putty so can't comment on that.

 

[Cubist]

A quick reply to your question. Yes sharp sand comes in different colours. Even the same sand can have different colours due to being done in batches. Once the lime is added it will go quite light so you might find yellowsharp sand is fine. We use natural hydraulic lime. (NHL) which comes in different strength. The NHL 3.5 is middle and easier to get hold of at our building supplies. We
've not used putty so can't comment on that.

I've been using a Lime Putty / Sand blend this year to fill the shrinkage gaps around the infill panels for the timber frame of the house; with mixed results - pardon the pun. There's a fine art to the choice of sand (how wet or dry), how vigorously it is mixed, the weather conditions and application techniques all of which can conspire to affect the quality of the result. For the work you need to do I would definitely go with a pre-mixed mortar to get the required consistency of appearance and performance.

 

[plasticpigeon]

Is your house Victorian??? I know it is not what you have said you want, but in a Victorian house, a cast iron insert is more traditional and would cover a multitude of sins!!!!

 

[Flyfisher]

I'm still unsure how to block the chimney up at the bottom to stop further soot falling down, was thinking maybe batton all around about 1 course up inside the chimney, and screw a sheet of marine ply to the batton, possibly with a vent in it

Stoves get hot. Very hot. Heat rises. Ply is a bad idea. I've not got a stove yet so I've not researched this properly, but some sort of cement board would be more my thought. For the amount you need it would probably not be dissimilar in price. A sheet of cement aquapanel might do the trick.

Ply would probably be ok as there is no current intention to fit a stove but it would have to be replaced if a stove was fitted in future.

For our inglenook I used some angle-iron and galvanised sheet steel, though the size of the chimney helped as I could stand in the fireplace while fixing it all. I dare say Abi's suggestion of some type of 'cement board' would also be ok. The steel sheets are not fixed and simply lay in the frame formed by the angle iron, which makes them easy to remove for periodic cleaning of all the dust and detritus than seems to fall down chimneys. Not had any problems with this arrangement over the past four years. I had intended to paint the steel sheets black but since they are not visible unless I really crouch down I've not bothered.

 

[TheForge]

Thanks for all the replies and pics, very encouraging to see so many people have done similar.

@Easrow - ahh so sharp sand comes in different colours? I assume I'll need white. When you say 3:1 sand & lime, what sort of lime - like the lime putty Livias suggested? It won't be hard getting these old bricks out, even the good mortar breaks down quite easily.

I've watched all the videos I can on repointing in both lime and cement, and repointing with lime seems a lot easier/more forgiving - am I right?

Lime is the correct material for the age of house, it will accommodate seasonal and temperature related movement and won’t damage the bricks. If there are any issues with moisture ingress into the chimney lime mortar will aid the evaporation of the moisture out of the building fabric.

Once you have a mix, clean the joints to be repointed, remove any loose material, wet down to control suction and push the mortar to the full depth of the joint. I would leave it fractionally proud and then beat back (don’t brush along the joints as you’ll get drag marks) with a churn brush when the mortar is ‘green’ hard and beginning to firm up. This will reveal the aggregate.

There are literally hundreds of sands dependant on the source and these come in a variety of sizes depending upon sieving etc. The sand colour will largely dictate the final mortar colour and directly affect its performance. Limestone derived sands have been shown to have a beneficial effect on carbonation of the mortar. Ideally the sand should be a washed sand with a good range of particle sizes within it. This is sometimes referred to as well graded but graded to what?!

More info on sands at:
https://www.roseofjericho.co.uk/product-category/sand-aggregates

There are many suppliers of pre mixed mortars as well as Ty Mawr, Rose of Jericho, Mike Wye and Limebase being some.

Lime putty is closer to historic mortars although NHL limes have become popular as they are supplied hydrated in bags like cement.

There is however increasing evidence of hydraulic limes causing damage to building fabric when incorrectly specified due to relative hardness and limited porosity. I would suggest only using NHL2 if you do choose to use NHL. Modern NHL 3.5 has properties more akin to what would have traditionally been used for engineering work.

http://www.nigelcopsey.com/reports/summary/summary_lime.pdf

 

[Spoilt Victorian Child]

For the work you need to do I would definitely go with a pre-mixed mortar to get the required consistency of appearance and performance.

So something like this?: https://www.lime.org.uk/pre-mixed-fat-lime-mortar-london.html

Also, Cubist, that Chimney Sheep looks good and easy in theory, but will blocking all draughts not lead to more problems later?

@TheForge - thanks for links. This is starting to sound complicated! I think pre-mixed is my way to go or I'll be here for a month deciding.

@Flyfisher - thanks will consider angle-iron as yes, that would make it easier to lift out and clean any debris.

 

[TheForge]

Duplicate post - sorry!

 

[Cubist]

So something like this?: https://www.lime.org.uk/pre-mixed-fat-l ... ondon.html

Yes, but as you can see there are several options in terms of colour and the grade (size) of the sand/aggregate available and some suppliers do provide a larger range. It's your choice of course but you may want to match the new material to other exposed mortar joints around the house.

Also, Cubist, that Chimney Sheep looks good and easy in theory, but will blocking all draughts not lead to more problems later?

Assuming that the chimney has not been permanently closed at the top of the stack or chimney pot using say a concrete or stone slab cemented in place then air will still be able to circulate in the cavity above the Chimney Sheep and the brickwork will still be able to breathe. Also, as I understand it, while these Chimney Sheep are quite dense they are permeable to air.

 

[Flyfisher]

@Flyfisher - wow, cool find behind innocent looking alteration!

Yes, we were rather pleased

Actually, I removed three different fireplaces before getting back to the original one shown. All were substantially smaller than the original and I guess it didn't take them long to figure out how inefficient such a large fireplace and chimney can be - though it would have been quite easy to send a small child up there for cleaning purposes :wink:

But the really good thing was that each iteration of 'new' fireplace had been built with such weak mortar and with no bonding to the previous brickwork that the bricks could be pretty much lifted out by hand. I hardly had to use a hammer and bolster at all and was able to remove most of it with a simply pry-bar. Because of this there was minimal damage to the insides of the original inglenook brickwork. I doubt the builders of yore were thinking about future occupants but it was a pleasant surprise to find something that was so easily reversible . . . unlike our many black-painted timbers :evil: