Open Fire - Hole in Upstairs Room?

anotheruser

We have an open fire downstairs.
In the room above the fire, there's a ventilation grill.
I took it off the wall as we're repainting the room.
The hole is about the size of a large malted milk.
Inside there seems to be a lot of dust, almost soil like substance.



Is this just soot?

Should I clear it out?

What's this vent for?
Can I fill it in?

Thanks

JohnB47

anotheruser wrote: »

We have an open fire downstairs.
In the room above the fire, there's a ventilation grill.
I took it off the wall as we're repainting the room.
The hole is about the size of a large malted milk.
Inside there seems to be a lot of dust, almost soil like substance.



Is this just soot?

Should I clear it out?

What's this vent for?
Can I fill it in?

Thanks

Sounds like the upstairs room used to have a fireplace and when this was removed, a ventilation grill was fitted to keep the void between it and the chimney pot on the roof ventilated. All pretty normal. The void is completely separate to the void between the downstairs fireplace and it's chimney pot above.

The stuff you are seeing inside is just soot and old brick dust and other things that have fallen down the void over time. Maybe the odd old birds nest too.

Just clear it out and you will be opening up that void to ventilation again. If you fill it in, you run the risk of the rain getting down into the void building up over time, this can cause a damp problem on the wall its fitted to and the flooring below.

I think it would be acceptable for you to cap off the chimney pot above and then block off the vent. When I say cap, I don't mean a perfect seal, its a cowl that is fastened to the top of the chimney pot and that is designed to leave air to circulate. Search the web for chimney cowl and you'll see what I mean.

Others might disagree with blocking off the ventilation point under any circumstances.

FreeBear

JohnB47 wrote: »

I think it would be acceptable for you to cap off the chimney pot above and then block off the vent. When I say cap, I don't mean a perfect seal, just a sort of hat that is fastened to the top of the chimney pot and that is designed to leave air to circulate.

Others might disagree with this last option.

Certainly clean out as much of the muck as possible. It will be a messy, dirty job. Capping the external pot is definitely worthwhile as it will prevent birds from falling in and dying. It will also stop rain getting in and causing damp. As for sealing up the vent - Two or three 25mm diameter holes should provide sufficient ventilation. Blocking it off completely could result in damp forming over time (especially if the pot isn't capped). Although... If you have a wood stove downstairs, the heat from the adjacent flue will drive off much of any damp.

[Deleted User]

Hi,


if you have a look up at your chimney pots you might find that the redundant ones are already capped and the stoor is just what has fallen over time.

anotheruser

I'll have to take a proper look but I don't think it is capped off.

Cleared out a lot of soot and muck, then bigger pieces of mortar fell so I've left those.

Put the fire on today and I can really smell it in the room above. Perhaps the soot and crap was blocking some out.

Thinking perhaps a sponge and some socks shoved in there would help with the smell?

I know I need someone to check the cap above but that isn't practical immediately now.

bris

anotheruser wrote: »

Thinking perhaps a sponge and some socks shoved in there would help with the smell?

bloody hell are you serious?

You need an engineer out to look at the chimney. If it's blocked you will be spilling CO2 into the room, that's lethal.


It needs smoke bombed and checked at every level.

JohnB47

bris wrote: »

bloody hell are you serious?

You need an engineer out to look at the chimney. If it's blocked you will be spilling CO2 into the room, that's lethal.


It needs smoke bombed and checked at every level.

Just to second this excellent post - CO2 (carbon dioxide) is odourless. So don't imagine reducing the smell is reducing the huge risk.

You are lucky that the smell is giving you a warning to do something about this ASAP (and without lighting the downstairs fire before doing it).

FreeBear

bris wrote: »

You need an engineer out to look at the chimney. If it's blocked you will be spilling CO2 into the room, that's lethal.

It needs smoke bombed and checked at every level.

Carbon Dioxide (CO2) is relatively harmless - It is used to give the fizz to fizzy drinks. The one to worry about is Carbon Monoxide, abbreviated to CO - Note, no 2.

Get the chimney swept and smoke bomb tested. Any leaks in to adjacent rooms means the chimney should not be used until a repair has been made. Also get a carbon monoxide (CO) alarm in this bedroom if you plan on using the fire downstairs. If the flue is leaking, an alarm could save a life.

bris

FreeBear wrote: »

Carbon Dioxide (CO2) is relatively harmless

Ha, yea I know I deal with it nearly every day, I don't know where the 2 came from, blonde moment, although it's more grey than blond now.

JohnB47

bris wrote: »

Ha, yea I know I deal with it nearly every day, I don't know where the 2 came from, blonde moment, although it's more grey than blond now.

Darnit, yes carbon monoxide. I followed your lead!!

ANDY597

Let's rewind a little, is socks and a sponge a wind up!

Buy a packet of smoke bombs from toolstation they arent expensive.

But a monoxide detector, also not expensive.

Smoke test the chimney downstairs, is anything visibly leaking upstairs.
Check outside, identify which pot the majority of the smoke is coming out of.

Test the chimney upstairs, identify the pot. Your homework should be finished there.

Get someone to look at it properly. Old unlined chimneys are notorious for leaking. If you have a stove consider using a steel liner.

Until then your running big risks, monoxide is a silent killer, look out for drowsiness, nautious and sore heads as initial warning signs.