Vent on chimney breast

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if I brick up a fire they get a vent if some one caps the chimny what you dont want is dead air as youll be getting fruiting bodies, be gentle!
 
Vent on chimney breast
Originally Posted by bodplasterer Vent on chimney breast
The flues should be separate surely?



My thoughts exactly, If they do join in the loft area then the hot gasses will only rise aided by the bedroom vent.

Vent or no vent, unless the chimney is almost totally blocked, gases will escape properly.

FWIW I usually just block bedroom vents.

I say

The flues don't join in the loft or attic in the sense that is implied. What happens for example; you have a one room wide by two room deep house. There are chimney breasts on the same wall in the middle of each room. In the loft or attic all the flues exit the house via one stack. The flues are worked from the centre of the room to the centre of the house but each flue is kept as a distinct entity.

This second statement is demonstrably wrong, a vent in a bedroom can be dangerous in older houses where the mortar is shot and another is in use.


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bubbles65 said:
Just thinking about this................. if you've bricked up the fireplace opening (which would be about 16" x 22" standard) and left a 9" x 6" or 9" x 3" vent, surely you have decreased the amount of toxic fumes/gasses finding their way into the room, and therefore - perhaps somewhat perversely - installed a HEALTHIER system for the client?
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I take the point. When you burn wood as we were in the particular instance you are deviating from the normal fuel used in the house. The resulting smoke is more easily seen and smelt. Think of it rather like a canary down a coal mine it is the sensitivity of the detecting device that warns you of the danger. In this case wood smoke warns people of defective flues. I now look forward to endless comments of canaries damproofing buildings.:RpS_drool:
 
i knew it would go the same way the rising damp thread went

Cleckhuddersfrance? ive not heard it called that before
we call it Cleckhuddersfax
 
NPS said:
i knew it would go the same way the rising damp thread went

Cleckhuddersfrance? ive not heard it called that before

we call it Cleckhuddersfax
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It refers to where I presently reside but also from where I come from.

I have passed the debate to some flue experts, well gas fitters to see if there is a code of practice for vents in redundant flues.
 
I dont see how smoke would come out of the other chimney upstairs they usually are seperate to each other just look on the roof and count the pots. If they were to connect lets say in the loft and all the chimneys were capped off then yes posibly the smoke would come back down from the top and come through the upstairs chimney but it would also come through the down stairs chimney. Oh and yes vent the chimney to stop condensation (or rising damp damp as steve likes to call it) coming through.
 
sliemasteve said:
It refers to where I presently reside but also from where I come from.

I have passed the debate to some flue experts, well gas fitters to see if there is a code of practice for vents in redundant flues.
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oh right i didnt know you was frog :RpS_mellow: how long you live over here?
 
I take it you have had bad experiences with chimneys Steve, I only know mine were separate due to the fact I opened one of them up to fit a range cooker into it there is also 2 breast's in my house which connect's to 2 separate chimneys, but each breast span over 3 floors with 3 separate flues in each and on the chimney there is 3 separate pots for each flue but I don't have any fires in any of the breast's just opened them all up and plastered, as the house is warm enough with the central heating, I also wouldn't be able to have an open fire as where I live it's a smoke free zone.
 
flynnyman said:
I dont see how smoke would come out of the other chimney upstairs they usually are seperate to each other just look on the roof and count the pots. If they were to connect lets say in the loft and all the chimneys were capped off then yes posibly the smoke would come back down from the top and come through the upstairs chimney but it would also come through the down stairs chimney. Oh and yes vent the chimney to stop condensation (or rising damp damp as steve likes to call it) coming through.
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Flynnyman where have you been? It is a widely understood and experienced event as below taken from National Association of Chimney Engineers web site. And note this does not preclude leaks at the ground floor level. Look at the number 1

C. REASONS FOR LINING
There are a number of reasons why an old chimney may need lining. These can be summarised as follows:
1) The flue is leaking smoke and fumes into other rooms or parts of the building.
2) Condensates or tar are seeping through the chimney walls causing staining either inside or outside the building (a common problem with wood burning stoves).
3) The flue is much too large for the type of fire or appliance being used.
4) The flue is too cold, particularly if on an outside wall, and is consequently not drawing properly.
5) If the chimney was built since 1965, but with the liners installed the wrong way up (regrettably this is quite a common occurrence!) tar and condensate leakage may occur.
6) The old flue surface is eroded and rough causing frictional resistance to the flow of the flue gases and resulting in poor updraft.
7) When a new gas fire is installed to an unlined chimney, lining should be considered if the old parging is crumbling with mortar debris continually falling onto the hearth, or if there is evidence of condensation. (see BS5440 pt. 1 -4. 1 .9.).

So this deals with smoke being emitted into a bedroom, .


Everyone on this site has probably blocked and plastered over fireplaces and put vents in, I have numerous times. The condensation that is normally in flues comes from the combustion of fuel I am not on about thisl. Out of curiosity can anyone explain to me, how in a chimney breast that has become redundant, that does not suffer from imaginary rising damp, from where does the moisture come from that requires a vent? Don't just say its necessary the question is why and clear reasons for the need .:RpS_thumbsup:
 
My understanding of it is that you put a vent into the bricked up hole so as to

1. primarily, maintain the ventilation of the ROOM

and

2. secondarily, ventilate the flue - in conjunction with a mushroom cowl or similar to prevent moisture build up due to the ingress of rainwater.
 
We as human beings give off moisture Steve so that's why good ventilation is usually required but due to the laws of nature its usually condensed to the coldest wall generally the external wall or the window so generally speaking its better to have an air flow going through the house.
 
flynnyman said:
I dont see how smoke would come out of the other chimney upstairs they usually are seperate to each other just look on the roof and count the pots. If they were to connect lets say in the loft and all the chimneys were capped off then yes posibly the smoke would come back down from the top and come through the upstairs chimney but it would also come through the down stairs chimney. Oh and yes vent the chimney to stop condensation (or rising damp damp as steve likes to call it) coming through.
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Flynnyman where have you been? It is a widely understood and experienced event as below taken from National Association of Chimney Engineers web site. And note this does not preclude leaks at the ground floor level. Look at the number 1

C. REASONS FOR LINING
There are a number of reasons why an old chimney may need lining. These can be summarised as follows:
1) The flue is leaking smoke and fumes into other rooms or parts of the building.
2) Condensates or tar are seeping through the chimney walls causing staining either inside or outside the building (a common problem with wood burning stoves).
3) The flue is much too large for the type of fire or appliance being used.
4) The flue is too cold, particularly if on an outside wall, and is consequently not drawing properly.
5) If the chimney was built since 1965, but with the liners installed the wrong way up (regrettably this is quite a common occurrence!) tar and condensate leakage may occur.
6) The old flue surface is eroded and rough causing frictional resistance to the flow of the flue gases and resulting in poor updraft.
7) When a new gas fire is installed to an unlined chimney, lining should be considered if the old parging is crumbling with mortar debris continually falling onto the hearth, or if there is evidence of condensation. (see BS5440 pt. 1 -4. 1 .9.).

So this deals with smoke being emitted into a bedroom, .


Everyone on this site has probably blocked and plastered over fireplaces and put vents in, I have numerous times. The condensation that is normally in flues comes from the combustion of fuel I am not on about thisl. Out of curiosity can anyone explain to me, how in a chimney breast that has become redundant, that does not suffer from imaginary rising damp, from where does the moisture come from that requires a vent? Don't just say its necessary the question is why and clear reasons for the need .:RpS_thumbsup:
 
henry said:
What did you do in your working life steve.
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I left school at 14 just short of 15. I did a six year craft apprenticeship. Went to night school and day release and won a scholership to unversity when I was 20. Four year sandwich course. At 24 took on my first job as main contractor having bought an old house in my spare time. Was a supervisor and manager and general dogsbody for others till 29. Next ten years plastering and damproofing and building business of my own employing max of 12 people. Small fry building activity. Got pissed off with planning department plonkers in the 90’s and did course on Historic Conservation at Oxford University and conservation law and practice module at Oxford Brookes at same time. Then went to De Montfort and did an M.A in Architectural Building Conservationa, this was all part time. Became member of Association of Conservation officers ( now Inst. of Historic c Buildings Conservation) and associate of Chartered Inst Of Building.
In defence from the possible assault from Irish and Flynnyman.....When I do intelligence tests I am good for 100 and anything over is good luck. I am not academic I have tried for O’Level English twice, many years ago and failed. I was a complete failure at school having failed the eleven plus but the panic of unemployment and what to do when I left school motivated /drove me to limited success in my last year in the awful school that I attended. I am much happier working with my hands than brain.
 
bubbles65 said:
My understanding of it is that you put a vent into the bricked up hole so as to

1. primarily, maintain the ventilation of the ROOM

and

2. secondarily, ventilate the flue - in conjunction with a mushroom cowl or similar to prevent moisture build up due to the ingress of rainwater.
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Reply Thanks. Concerning 1. That's the argument nowadays ie passive ventilation it may have held before but I don't recall heard it.

2 I can see that this would help keep the stack dryer but decent flashings and soakers are good for 100 years. The reasonm I understood the need for the vent was the removal of condensation but never thought about where it was coming from.
 
I would be only guessing steve to your question so will pass on it. what I like to ask you is what you think about dpc firms what insert the plactic strip dpc. My thoughts on this is it just dont seem right to disturb the brick work like this . What I have seen
of this is when they put the bricks back they pack with slate which I would not be happy about and make good with mortar I would of thought some type of fast setting grout would be better then slate.
 
bodplasterer said:
Seems like an interesting life you have had Steve
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Really? Sounds boring as hell to me...far too much swatting up.

Why didn't you chose the drink and drugs route Steve, much more fun.

And I hardly ever think about the physical movement of H2O or flow diagrams of double venting chimneys.
 
cant be arsed to read this thread any more cant we just delete it?????????????? its getting just like the rising damp thread ========WAN K
 
DannyMac said:
Really? Sounds boring as hell to me...far too much swatting up.

Why didn't you chose the drink and drugs route Steve, much more fun.

And I hardly ever think about the physical movement of H2O or flow diagrams of double venting chimneys.
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I take it my sarcasm is to subtle.
 
NPS said:
cant be arsed to read this thread any more cant we just delete it?????????????? its getting just like the rising damp thread ========WAN K
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Do what I do with the machine section.....DON'T FKIN READ IT!

How you getting on with them ideas I sent ya?
 
just waiting for replies mate, most of them contacts from the links dont do the publications its an outside company that do it if you get me, im looking to get the details of the companies that publish the books, but without knowing someone who has one of the books its a hard job lol
 
irish_spread said:
It's NOT difficult.


Answer my question.

Is it more dangerous for my neighbour to light a fire in their fireplace than it is for me to light a fire in mine ?

Think about it for a couple of hours
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You quote loads of other "experts"


Basically, answer the question






YES OR NO ????
 
There seems to be a lot going on in this thread and with bubbles talking in code am not sure were I am LOL Are going to have a potting shed section this year.
 
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