Sealing flue liner to lintel gap

Dugsy

Have done most of the air tightness taping and membrane installation in my house, but am looking for suggestions on sealing between a chimney lintel and flue liner above a stove which I have installed. My main concern is about what effect the high temperature in that area may have on any possible fix. Suggestions appreciated.

gman2k

Have you tried fireproof cement? You can get a product in mastic tube format from most good builders suppliers.

Poor Uncle Tom

Or if the space is a little wider you can get an Intumescent foam spray to fill the gap.

gman2k

Poor Uncle Tom wrote: »

Or if the space is a little wider you can get an Intumescent foam spray to fill the gap.

I wouldn't recommend an intumescent in this instance, as it's only designed for the one 'burning' so to speak to prevent spread of flame and gas.

feckincrazy

fireproof insulation between the 2.

Carlow52

Dugsy wrote: »

Have done most of the air tightness taping and membrane installation in my house, but am looking for suggestions on sealing between a chimney lintel and flue liner above a stove which I have installed. My main concern is about what effect the high temperature in that area may have on any possible fix. Suggestions appreciated.

I dont get the issue here.

Normally the lintel is there to support the fireplace ope

The chimney is probably concrete block built in the shape of a square or rectangle and the flue will be fully concreted into this structure, in fact the last piece of flue may rest on the lintel.

If this is the case then before the stove went in, the flue should have been airtight in the concrete block stack so if u blocked the flue room airtight.

Then u fit the stove and flue liner and the flue liner is airtight in the flue and stove so room still airtight when stove draught shut.

Therefore sealing between the flue liner and lintel has me puzzled

Fire cement/heat resistant plaster/weak mix concrete will all fill the gap but whats the end finish