Re-pointing chimney stack

[Finally_motivated]

I'm going to take advantage of scafflolding access to my chimney stack and plan to re-point it.
Property is about 100 years old.
Gaps can be seen from ground level in quite a few of the joints. I don't know what condition the flaunching is in.

Does anyone have any tips/advice on repointing this area, ie mix to use (remembering that the original mortar is lime based).
What would be a good joint to use, I like weatherstruck or would flush be okay. Any tips on achieving flush joint, what tool to use.

Thanks in advance.

 

[Nige F]

Try www.mikewye.co.uk

 

[dunc]

Hi,
First carefully check contition of brickwork and joints. Often this can be very poor and difficult to see from ground level. Assuming its repointing only I would use a 9 parts soft and graded sand, 3 lime and 1 cement. Sieve the sand through a vegetable strainer, this takes out any small stones....
Cut out all of the mortar to a depth of 25-30mm with a small angle grinder with 10mm disc. Then either buy a pointing gun or a cheaper option a catering 'piping bag'. Mix up small amounts using something to measure accuarately with, no more than 1/3rd of a bucket. Mix needs to be creamy, add a little plastiseser if necessary. Its sooooo much quiker than trowelling in a few inches at a time. Pipe into the joint leaving the mortar protuding, this means you don't have to go back and mess around with a trowel filling odds and sods in!
When you have done a couple of courses strike off the excess with a trowel and finish as reqd.
Enjoy!

Dunc