Wagas Posted August 30, 2020 Share Posted August 30, 2020 We've got log burning stove with a flue that goes through the ground floor ceiling and then behind a dwarf wall on 1st floor and then out of the roof. It's got a vent on the ground floor ceiling and if you stand under it it's like standing next to an open window! I presume it's there for a reason but it seems a bit ridiculous. Any ideas on what we can do? Link to comment Share on other sites More sharing options...
SuperJohnG Posted August 30, 2020 Share Posted August 30, 2020 I dont know too much about them but the vent is required to provide air for the fire to burn which is normal. You would want to convert it to a room sealed stove then it wouldn't be bringing a chill in. See here for details on room sealed type. https://www.stovesonline.co.uk/external-air-stove.html Link to comment Share on other sites More sharing options...
Gav_P Posted August 30, 2020 Share Posted August 30, 2020 I assume you have a fairly new home and / or the stove is over 5kw. So HETAS reg say you need an air vent to ensure you don’t create a vacuum inside the house. The vents size can be calculation from the size of the stove and the air tightness if your home. The shouldn’t be blocked. However they only need to be quite small (maybe a couple of inches for smaller stoves). There are some stoves that come with integrated ventilation so you don’t get the drafts (but that won’t help you). You can get different collars without the vents if it turns out you don’t need the ventilation or have an alternative. Link to comment Share on other sites More sharing options...
ProDave Posted August 30, 2020 Share Posted August 30, 2020 The "issue" will be further up. A flue pipe like that cannot touch flamable materials, typically it must be kept 50mm away from anything flamable, so that grille is covering an over size hole in the ceiling. At some point, the flue will pass into a cold loft, or straight out through the roof. The same applies. You cannot let any flamable material touch the flue. What i suspect has been done here is the installer has just left big gaps so cold air from the loft or outside the roof can get in and down the space around the flue and down into your room. There is a solution. the manufacturer of my flue make an insulating sleeve to go around the flue pipe which is a tight fit to the flue pipe. It is obviously made of a non flamable material. With that you can then make the opening through a celing or roof sealed and air tight and no cold air will get in. Who built the house and when or who installed the stove? EDIT: reading the above, I very much doubt this is the intended air intake. It might be doing that by accident, but the intentional air intake is usually low down near the stove. 1 Link to comment Share on other sites More sharing options...
Wagas Posted August 30, 2020 Author Share Posted August 30, 2020 This stove has been installed with external air. The vent doesn't provide any air for the fire as it's on the ceiling ? This pic probably explains it better: Link to comment Share on other sites More sharing options...
Wagas Posted August 30, 2020 Author Share Posted August 30, 2020 3 minutes ago, ProDave said: The "issue" will be further up. A flue pipe like that cannot touch flamable materials, typically it must be kept 50mm away from anything flamable, so that grille is covering an over size hole in the ceiling. At some point, the flue will pass into a cold loft, or straight out through the roof. The same applies. You cannot let any flamable material touch the flue. What i suspect has been done here is the installer has just left big gaps so cold air from the loft or outside the roof can get in and down the space around the flue and down into your room. There is a solution. the manufacturer of my flue make an insulating sleeve to go around the flue pipe which is a tight fit to the flue pipe. It is obviously made of a non flamable material. With that you can then make the opening through a celing or roof sealed and air tight and no cold air will get in. Who built the house and when or who installed the stove? If it's just a case of not touching anything flammable why does the grill have to be a vent, why can't it just be solid? I built the house ? and HETAS installer installed the stove and flue. The problem is behind the dwarf wall is a large cavity before you get to the external wall. I'm not going to be able to put an insulated sleeve around it now. Is there any reason why I can't use a solid 'ceiling plate' to at least block off the draught rather than have this vent? Thanks Link to comment Share on other sites More sharing options...
Russell griffiths Posted August 30, 2020 Share Posted August 30, 2020 If it’s like mine then that grill is not a vent, it just has holes in it as a pattern to make it look pretty, as Dave said it is more a spacer to keep the pipe a set distance from any flammable surfaces. As dave said again you probably have a poor install with gaps around the flue which is allowing the cold to travel through the grill. 1 Link to comment Share on other sites More sharing options...
Wagas Posted August 30, 2020 Author Share Posted August 30, 2020 1 minute ago, Russell griffiths said: If it’s like mine then that grill is not a vent, it just has holes in it as a pattern to make it look pretty, as Dave said it is more a spacer to keep the pipe a set distance from any flammable surfaces. As dave said again you probably have a poor install with gaps around the flue which is allowing the cold to travel through the grill. Ah ok. So if it's just for show I can replace it with one without holes and/or try and get a specialist sleeve up there. Link to comment Share on other sites More sharing options...
Russell griffiths Posted August 30, 2020 Share Posted August 30, 2020 My flue changes from the un insulated grey version to an insulated version just before it goes through the ceiling, this allows the flue to be in closer contact with surrounding materials. I think i would go back to the installer and check first, as I might be talking out of my backside, please check. Link to comment Share on other sites More sharing options...
Wagas Posted August 30, 2020 Author Share Posted August 30, 2020 From a google search it seems that it is a vent and not just for looks: The Shieldmaster Ventilated firestop plate should be used when passing through a ceiling. The slots cut out of the plate allow for cool air to ventilate between the floors of the property whilst preventing the spread of fire. For compliance with the building regulations, a ventilated plate must be used. Link to comment Share on other sites More sharing options...
PeterW Posted August 30, 2020 Share Posted August 30, 2020 That is a ventilated flue plate so that you cannot get a build up of fumes behind the wall in the enclosed space of the flue fails Link to comment Share on other sites More sharing options...
ProDave Posted August 30, 2020 Share Posted August 30, 2020 This is the insulated sleeve I mentioned, being prepared before passing this bit of pipe through the roof. The roof structure can then be sealed to the outside of the insulated sleeve ensuring no cold air enters the house. Even of you replaced the ceiling grill for a solid one, you would still have the cold air getting in through the roof, and into the void behind where the flue pipe is hidden, and it would still be cooling the house only it would not be so obvious. You do need it solved either where it goes into a cold loft, or where it exits the roof. This is the BIG problem with the UK building industry, very few people understand problems like this or take the care to avoid them happening. Link to comment Share on other sites More sharing options...
Wagas Posted August 30, 2020 Author Share Posted August 30, 2020 But wouldn't that insulating sleeve block up the vents and negate the effectiveness of the ventilated flue plate? Link to comment Share on other sites More sharing options...
jamieled Posted August 30, 2020 Share Posted August 30, 2020 @ProDave presumably that sleeve would work on any twin wall flue of the right diameter. Out of interest, where did you get hold of it? Link to comment Share on other sites More sharing options...
Russell griffiths Posted August 30, 2020 Share Posted August 30, 2020 See told you I was talking rubbish. Link to comment Share on other sites More sharing options...
ProDave Posted August 30, 2020 Share Posted August 30, 2020 It came from flue-pipes.com 1 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now