GreenVision Posted July 3, 2023 Share Posted July 3, 2023 Hi all. Moving into loft this year at some point, kids are getting too old for excuses so its back to the loft space. Not ever used the chimney before, in my two other loft builds I extracted down into a bedroom via built in wardrobes, but this time I need the air going straight out the loft and the chimney is my only option. My current plan is to drill a 12 inch hole and fit a really solid flange into the chimney then just fix the ducting to it. I'm hoping someone has done something similar before and can advise on how safe it is. Really don't want the chimney coming down on me. Cheers. Link to comment Share on other sites More sharing options...
Ajimango Posted July 3, 2023 Share Posted July 3, 2023 Won't a 6 inch hole do? Recently had a look at our chimney. At ceiling level in the loft, almost the whole of one side had been eroded. Didnt want that falling on us while asleep. I fixed it with a small concrete lintel. Dont take chances with things like this. 2 Link to comment Share on other sites More sharing options...
hashbrown Posted July 3, 2023 Share Posted July 3, 2023 If the chimney is brickwork you could gently take a few bricks out for the size you need and just wedge back up any that came loose. ( the bricks will form a natural arch if too many fall) But if it is stonework that's a different kettle of fish as you could have the lot come down. Link to comment Share on other sites More sharing options...
GreenVision Posted July 3, 2023 Author Share Posted July 3, 2023 (edited) 17 minutes ago, Ajimango said: Won't a 6 inch hole do? I have a 12" fan mate so no not really, I cant get a loft tent up there so it a full build. I run a 12" on a controller at a max of 75%, that way I can still get up to 3000m3 P/h if needed in summer, and its quiet as a grave as its slowed down. I could run an 8" or 10" at full revs but it would be twice as loud, plus its another £400 or so spend on a new EC fan, kinda stuck with the 12". 15 minutes ago, hashbrown said: take a few bricks out This was actually my first thought, the chimney at roof height is about 500mm-600mm wide so likely 4 bricks minimum across the chimney, 1 and a half bricks across by 3 down would be a big enough hole I rekon, but a circular hole I think would give me more strength in the brickwork. I'm thinking it would work the same way an arch works, strength by shape. But removing bricks is an option. With a square hole I could re-enforce it with timber like you would a window or door etc and use a square to round flange. Pretty sure its not stonework, I live in a south east terrace not the Cotswold's That said it is covered in screed so I may end up eating those words.. Edited July 3, 2023 by GreenVision 1 Link to comment Share on other sites More sharing options...
Herbal Kint Posted July 3, 2023 Share Posted July 3, 2023 Is chimney in use ? Aiming at don't poison yourself If not then what they said up,reinforce it a bit and mix some concrete to fill it up,not a big job but if loft is not insulated then you got shit loads to do. Link to comment Share on other sites More sharing options...
GreenVision Posted July 3, 2023 Author Share Posted July 3, 2023 Just now, Herbal Kint said: Is chimney in use ? Aiming at don't poison yourself If not then what they said up,reinforce it a bit and mix some concrete to fill it up,not a big job but if loft is not insulated then you got shit loads to do. No mate Downstairs it totally blocked off, central heating was already here and I filled in the fireplace with OSB and platerboard myself. Yh its a MASSIVE job. I need to re-insulate the loft floor, then insulate roof rafters, floor out about 20m2 and board the ceiling and uprights. Huge job, but its gona see me for the foreseeable future so worth it. 1 Link to comment Share on other sites More sharing options...
Herbal Kint Posted July 3, 2023 Share Posted July 3, 2023 Yeah ,good luck,I got same job to do but can't force myself to do it,lack of cash doesn't help Get a decent mask and glasses or you will be coughing dust out for a week if it looks half bad as my attic Link to comment Share on other sites More sharing options...
GreenVision Posted July 3, 2023 Author Share Posted July 3, 2023 Mate I'm gona need a full suit and half mask respirator. There's an old concrete water tank up there I've got to break up and remove, pretty sure they used to put a small % of Asbestos in those so I'm going the full Buzz Lightyear on it. Link to comment Share on other sites More sharing options...
Herbal Kint Posted July 3, 2023 Share Posted July 3, 2023 I remember my old man saying it's just a bit of dust,my CT scan disagrees Good luck with the venture GV Link to comment Share on other sites More sharing options...
sweettooth Posted July 3, 2023 Share Posted July 3, 2023 cant you go out under eaves? use a few of those square ducting converters, i have a 10" going into a large plastic box with 4 x 6 inch spiggots on it which goes out to 4 individual vents dotted around the eaves Link to comment Share on other sites More sharing options...
geogeo Posted July 3, 2023 Share Posted July 3, 2023 hi mate watch the old tank !!! yes made off asbestos , the y use'd to use in council houses . if you can put into a space in attic an leave it dont use power tool to knock it to f---k be careful Link to comment Share on other sites More sharing options...
GreenVision Posted July 3, 2023 Author Share Posted July 3, 2023 5 minutes ago, sweettooth said: cant you go out under eaves? use a few of those square ducting converters, i have a 10" going into a large plastic box with 4 x 6 inch spiggots on it which goes out to 4 individual vents dotted around the eaves I could well do mate, its defo an option. But I do have a 12" fan and limited space. The chimney is dead center of the loft so it make sense to use it as the filter is best hung as central as possible. But the eaves are 100% a close second option atm. If I get to the point of using the chimney and don't like the way it feels I will be going out via the eaves for sure. Its actually the reason I'm asking here, if I feel the chimney is too risky I need to prepare to split my 12" fans exhaust into four 4" ones for the eaves. Link to comment Share on other sites More sharing options...
GreenVision Posted July 3, 2023 Author Share Posted July 3, 2023 Just now, geogeo said: hi mate watch the old tank !!! yes made off asbestos , the y use'd to use in council houses . if you can put into a space in attic an leave it dont use power tool to knock it to f---k be careful It a really low % of grey Asbestos, around 7% average. I've done a fair bit of research on removing it. You can pay to have it removed, but if the firm have to break it to get it out the loft they charge about £300 for a 20 min job. Which they will have to do. I think the best option for soind it yourself is to have a respirator with the correct filters, full body coveralls and goggles. Then cover it with a dust sheet and carefully use a hammer to break it into a few a pieces as possible. Then pick up the whole lot (dust sheet and all) and put it into a very large heavy duty dust refuse sack and use duct tape to seal it off. Triple it up with sacks and dispose of properly. I'm gona have all the equipment anyway as I'm using insulation. But I'd rather not be doing for sure, just not much choice, its gotta go. 1 Link to comment Share on other sites More sharing options...
geogeo Posted July 3, 2023 Share Posted July 3, 2023 (edited) Just now, GreenVision said: It a really low % of grey Asbestos, around 7% average. I've done a fair bit of research on removing it. You can pay to have it removed, but if the firm have to break it to get it out the loft they charge about £300 for a 20 min job. Which they will have to do. I think the best option for soind it yourself is to have a respirator with the correct filters, full body coveralls and goggles. Then cover it with a dust sheet and carefully use a hammer to break it into a few a pieces as possible. Then pick up the whole lot (dust sheet and all) and put it into a very large heavy duty dust refuse sack and use duct tape to seal it off. Triple it up with sacks and dispose of properly. I'm gona have all the equipment anyway as I'm using insulation. But I'd rather not be doing for sure, just not much choice, its gotta go. maye get the kids away for the day !! soak a heavy dust sheet in water ?? Edited July 3, 2023 by geogeo Link to comment Share on other sites More sharing options...
sweettooth Posted July 3, 2023 Share Posted July 3, 2023 10 minutes ago, GreenVision said: I could well do mate, its defo an option. But I do have a 12" fan and limited space. The chimney is dead center of the loft so it make sense to use it as the filter is best hung as central as possible. But the eaves are 100% a close second option atm. If I get to the point of using the chimney and don't like the way it feels I will be going out via the eaves for sure. Its actually the reason I'm asking here, if I feel the chimney is too risky I need to prepare to split my 12" fans exhaust into four 4" ones for the eaves. I was trying to use my chimnery but the tops are capped, often when its sealed up/decommisoined , the tops will be capped to some degree, you may find pushing a 12" at 75% wil either blow the cap off or create back pressure and start feeding into the house or even worse, into next doors chimneys?? Link to comment Share on other sites More sharing options...
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