Repairs to brick pillar

[zena123]

Bricks of top 3 courses of pillar at one end of 8ft wall (at bottom of garden) were loose. I've 'lifted' or eased out about 20, plus a few red engineering bricks laid 'brick on edge' on the top of the wall that had also loosened. The frogs (& also the 'mortar') on these top 3 courses seems made of compacted sand, which scrapes off or breaks away fairly easily. Rest of the wall is stable.

It was built by a well-known housing developer 20 years ago, and the top 3-5 courses of boundary brick walls in other places on our estate look less 'professional', as if 'finished off' maybe by an apprentice, or maybe the 'mix' was changed.

My question : could the 'sand' that I am removing be a mix of sand & lime and so a legitimate way of bonding bricks on a boundary wall? If so, then should I replace it with a mix of
sand: lime (presumably 2:1) or should I do: cement:sand:lime (1:2:2) or will a
cement:sand (1:4) mix work (or be too brittle).
Tx in advance for any advice !

 

[^woody^]

Sand and cement, not lime - unless you meant to say it was built 120 years ago

1:3 for the coping/capping and the wall below should really match (in colour) the other mortar or it will look odd

 

[zena123]

Thanks for replying Woody. The 1:3 will make the colour look grey-ish (as there's more cement) won't it ?? But I'll try it .... I also saw a suggestion on this forum to add Everbuild 503 Premium SBR to the mix (as well as 'paint' the brickwork with it first) to reduce the chances of cracking/shrinking & frost damage. Any views on that ?
Also: What do you make of the bonding that is already there, which is basically sand? When loosened up a bit, it can simply be brushed out & I'm collecting it in a bucket & to all intents & purposes, it looks & feels just like sand alone. In 2000 would substantial garden walls (it's 2 bricks thick) have been built like that & passed whatever building regulations may have been in place?? I'm asking, as you reply to a lot of people's queries, & you seem very well informed. Afraid I'm taking advantage of your generosity here ! But mega Tx for your time !

 

[zena123]

... not 'there's more cement' ... I meant to say, 'there's less sand' as the ratio you suggest I should use is 1:3, as opposed to the 1:4 I was thinking of using !!