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 !
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 !