Top of chimney

[cdbe]

I've cleaned everything off the top, pointed the outside. All the flues are redundant, my side only has stack and what's in the loft left, neighbour still has the whole lot.
I have 2 good pots to put back on neighbours and was going to leave his gas cowl in the middle, on my side I plan to cover the holes with roof tiles and then re-flaunch the whole lot.

Questions:

Some of the inner bricks are loose, the cement having been replaced by weeds, would you start rebuilding these, given that the new flaunching should do a good job of holding everything together?

What mix for the flaunching?

The gas cowl is connected to a liner so if I just flaunch on top of that aluminium plate the flue itself won't be ventilated, just the liner - is this a problem, it's how it was before? If it was my side I think I'd buy a pot and push the liner out of the way to vent the actual flue but neighbour won't want to pay for that - any easier solutions?

Thanks.

 

[^woody^]

You should be Gas Safe to work on that flue, or it should be tested afterwards by someone who is. Otherwise you will be responsible for any spillage or other problems.

You don't need to ventilate a flue that is lined and in use.

Any loose bricks should be re bedded. The problem with just face pointing, or leaving joints void like you have there, is that sulphates are sill in the mortar and every time they get wet, they soak into the new mortar and if you have not used sulphate resistant cement then the joints degrade quickly.

2:1:1 for the flaunching - sharp:building:cement

 

[cdbe]

Thanks. None of the flues are in use. Neighbour has had back boiler and all gas fires removed, chimneys blocked with balloons and electric fires installed - I just think if I flaunch that cowl in when it's attached to the (redundant) flue liner it's not ventilating the chimney?

I'll make good all the brickwork.