chimney lining??

[cotegreen]

just a enquiry to those people in the know on these things. I need to line my exisiting chimney which is used for an open fire. i have looked at the standard stainless steel liners and have had quotes around the £1300 mark including making the relevant hood. i have also looked into a concrete lining however had heard horror stories about it pushing chimneys out etc along with the fact that they want to knock a 18" hole in the breast on both floors to centre the former. so after a bit more research, i have found a complany called theromcrete, which seems to have a unique system of puring a lightweight mix of volcanic ash and clays into the chimney from above with a balloon former that is deflated when it sets ( after 1 hour). the chimney is stablisised they say, all gaps in joints are filled and its all guaranteed for 25 years. on top of this there is no knocking holes in any chimney breasts . it sounds like the best solution by far?

this is around the same price as a normal stainless liner so does anybody have any experience of it all. i am trying to get the job done pre christmas, so any help would be appreciated. thanks!!

 

[MdB]

I wouldn't call it unique. I believe various people do that sort of thing and it has been done in our neighbours chimney. It seems to have worked well for them and has been in situ for 10 years or so.

The downside is that it is a one way street. If it fails (through movement in the chimney) for example, or if the hole is made too small - you are then stuck and have a rather expensive problem to fix.

 

[spot]

When I needed my chimney re-lining (September 2010) I looked at the options and decided a ceramic lining was the best way to go and got these people in http://www.landyvent.co.uk/lining.
Unfortunately once they came and did the pre installation inspection they discovered some bricks had collapsed between the downstairs and upstairs chimneys and getting this repaired would've meant major shag and hassle so we ended up going for the metal liner instead.
This was disappointing as I believe the ceramic lining was a better option, but this wasn't going to happen without spending a load of extra time, money and effort to fix the brickwork issue.
Landyvent were fantastic and the liner was installed very quickly and they did a great job replacing the bricks and cleaning up afterwards.

So i'm not sure if the concrete lining you're talking about is similar to the ceramic one Landyvent do? But if it is, I would go with that as opposed to the steel liner. I believe the advantages outweigh any disadvantages.

Edit - I just bothered reading the Landyvent website again and this ceramic lining IS different to what I think is the concrete lining you're referring to and it sounds like one major drawback of the concrete as opposed to ceramic is the reduction in the size of the flue due to the thinkness of the concrete.
Follow the link and see what you think....

 

[88v8]

The main problem with a poured liner is controlling it within the flue. There is nothing to prevent it from resting against the flue in places so that the thickness there will be minimal. This may be fine if you are just looking to seal failed parging & joints against smoke permeation, but is no good if you need heat insulation as with thatch + woodburner.

Stainless liners are expensive but reversible. With an open fire they will last many years, but with a woodburner I believe the cheap liners may only last 10/15 years.

Why does your chimney need lining?

Ivor

 

[Penners]

if the hole is made too small - you are then stuck and have a rather expensive problem to fix.

Wise words from MdB. Before you undertake a fix like this, you need to be very, very sure that it's the right one.

Years ago I took immense trouble (not to mention the risk to life and limb climbing on to the roof!) to sort out a porous chimney by inserting a stainless-steel liner and a register plate - only to discover that the diameter of my liner was too small for the volume of smoke that had to travel up it. The room simply filled with smoke!

:roll: We live and learn...

 

[MdB]

6.7 to 1 is the ratio that building control recommend. This is the area of you fireplace opening to the cross sectional area of the flue. A bigger ratio than this and you "may" have issues.

 

[Feltwell]

I do wonder if there is a danger that we assume chimney lining is always needed when it is not. I appreciate for stoves it is, due to the higher flue temperature - but, for instance, I want to put a cast-iron combination open fire back into our dining room, instead of the current bodge of a dog basket sat in the original builder's opening. Prior to that it apparently had a 1960's gas fire, venting into the unlined flue.

The fire smokes into the room sometimes at the moment, but we know that is because the ratio of opening to flue is wildly wrong. The stack seems sound enough - we've had the flue in question swept, and there's no sign of any leaks. I don't really see the point of going to the expense and hassle of lining it if we think there is nothing wrong with it. Is there a way of testing them properly? I know you can get smoke pellets and look for leaks, is there a better way of doing it? CCTV inspection seems overkill and I'm not convinced would spot anything other than a major problem anyway.

 

[Penners]

I don't really see the point of going to the expense and hassle of lining it if we think there is nothing wrong with it. Is there a way of testing them properly?

Oh, yes! My attempt at lining the chimney (narrated above) was prompted by a very revealing test. I lit a fire in the dining room fireplace of our Victorian Cotswold farmhouse. I thought everything was going well until Mrs P told me (in her most informative, Force 10 voice) that the bedroom upstairs appeared to be on fire.

Actually, it had just filled with smoke, thanks to a chimney that was slightly more porous than a sieve.

 

[MdB]

In our case it was simple to discover that the chimney was shot.

Remove a stone from this wall. Any stone will do. The back of it will be black. Basically, the centre part of the wall is hollow allowing smoke to move within it unrestricted. Not something I was happy with at all but the previous owner used it in that condition for many years.

 

[Feltwell]

That illustrates what I mean - sometimes it's rather obvious that action is needed, but if not.....

Usually I'd always stick to the "if it ain't broke don't fix it" method, but in this case with carbon monoxide involved I'm rather more cautious. The link that Spot mentioned above to Landyvent indicates that they do air pressure testing, which sounds like a good idea - but asking a chimney lining company to test your chimney sounds rather like asking a damp proofing company to test your house for damp, we all know what that does.......

 

[spot]

asking a chimney lining company to test your chimney sounds rather like asking a damp proofing company to test your house for damp, we all know what that does.......

Totally agree.
With ours it was obvious we had a problem as you'd light a fire downstairs and smoke would also come out of the vent from one of the blocked up bedroom fireplaces.

 

[Penners]

Remove a stone from this wall. Any stone will do.

OK, I've done that. What now?

 

[stuart45]

Air testing is a good method, but if it fails you still need the smoke test to see where it leaks. To do the smoke test properly the top and bottom of the flue needs to be sealed. Regs allow for some smoke to escape, but what is a safe amount is left to the discretion of the person doing the test.

 

[biffvernon]

I do wonder if there is a danger that we assume chimney lining is always needed when it is not.

What? Such Heresy! You dare to question the almighty Buildings Regulations?

I've been burning wood in woodstoves for over thirty years in various old chimneys, all without liners. I've come to the conclusion that the whole issue is bonkers.

 

[Feltwell]

I thought I might do my own smoke test - it can't be that hard, Screwfix sell smoke pellets, surely you just shove them in the fireplace, set them off and then check smoke is coming out of the appropriate chimney pot and nowhere else?

Perhaps not - the National Association of Chimney Sweeps have smoke tests down as being a full day's course at £275! But as Stuart says above, top and bottom of the flue need to be sealed, which frankly I wouldn't have thought of.

http://www.nacs.org.uk/docs/Training/Smoke testing procedures details.pdf

There is a sweep local to me who is qualified, chimneys do seem to be a bit of a "black art" in many ways so I think I may just get him in to sweep the chimney and check it's sound. Probably unneccessary but it's for peace of mind.

 

[MdB]

Remove a stone from this wall. Any stone will do.

OK, I've done that. What now?

:shock:

Put it back together again before we get back home.... (and more importantly Mrs MdB sees it!)

 

[MdB]

That illustrates what I mean - sometimes it's rather obvious that action is needed, but if not.....

The thing was, ours wasn't very obvious. We only found out the issues once we started renovating though I did have my suspicions. The black back to the blown plaster wasn't obvious from the front.

 

[cotegreen]

thanks for all the replies . i basically have leaks from my current chimney into the dining room and upstairs bedroom. having now got a young baby i cannot risk using the chimney anymore with it leaking. i opened up the chimney about 5 years ago and there has always been pieces of the liniing or parging as i believe its called , falling into the grate and just by looking up you can tell its in need of repair. whilst i have sealed up numerous draughts into the room which has done the 'draw' of the fire no good i will probably have to crack a window in a different room to get it draw correctly which is one of those things i need to live with. the other option is to put an air brick into a solid stone wall - which is not going to happen. i have been told that a 12" flue instead of the current 14" should not cause a problem however should it become a major issue i suppose i could put a stove in. so on this subject if i had a stove i take it smoke in the room is not an issue and the draw it needs is not as much? again all advice is much appreciated.

 

[biffvernon]

http://www.hotline-chimneys.co.uk/products.asp?category=Chimney+Sweeping&subcategory=Chimney+Sweeping+Brushes