140 year old red brick mid terraced - re-point using what kind of mortar?

It would probably consist of a strong hydraulic lime mix. 4 medium fine sharp sand to 1 N.H.L 2 lime.In my experience it will probably have a pozzolan added, which aids the set. This is usually fly ash.

If building has existing mortar, try and match what’s there already. Would be a lime based mortar mix at that age.

Most certainly lime based mix. The tricky part is getting the colour to match up harmoniously with the existing. Ash or brick dust etc might have been added. mortar Composition analysis can be done to determine the exact mix. ...Would suggest just ordering some NHL3.5...this is a standard Lyme mortar mix. Test a small area to see how it matches up in colour.

Hydraulic lime NHL 3.5 and sharp sand 1/3 1/4 ratio. Spray the raked out pointing with water prior to repointing. If you require a certain colour masons mortar will make it up for you. Check there website.

I would use a mix of three parts washed sharp sand, one part soft sand to one part mature slaked lime putty. Minimum depth of new pointing would be 30mm. Clean all dust from raked out joints and dampen before re pointing.

It would probably consist of a strong hydraulic lime mix. 4 medium fine sharp sand to 1 N.H.L 2 lime.