Insulating around chimney opening

[george121212]

Hi , I have a log burner which I don't use. Around the top of the chimney breast area there are a few gaps between the brick and board which are allowing cold air through and making the room a bit draughty.

Any idea how to safely insulate these safely and cosmetically? Pics attached thanks

 

[cwhaley]

I had the same issue when I installed my stove. I wasn't able to make a closure plate which fit perfectly into the opening of the flue.

I just used a layer of rockwool on top of the plate and around the edges. It's entirely non-combustible.

If you plate doesn't need to be removed, how about the black high-temp sealant? The gap looks quite small around most of the edges.

 

[george121212]

Thanks for the advice , seems like a good shout. Some of the gaps are sealable but others 2-3 cm so will need rockwool. Rockwool seems to come in large packs, any other products that might come in a smaller quantity? Thanks

 

[cwhaley]

I just used some from the insulation in my attic. You can buy rockwool slabs for a few quid online -- might be worth sourcing one of these and simply cutting it to shape to fit the gap. Here is an example:

Rockwool Slabs

Rockwool slabs are perfect for drip irrigation systems Rockwool can be used in conjunction with Danish Base Trays/Aqua Trays for optimal growing Structurally stable growing environment Perfect balance of moisture retention and aeration

www.futuregarden.co.uk

I've had my insulation in place three years with no ill-effects. I noticed after I installed it that there was a draught up the chimney around the gaps like yours' -- I did a smoke test and could see smoke being sucked up there when the stove was on.