Non existent pointing

[Argentum66]

Hello Everyone.
Looking for a bit of pointing advice. My Daughter bought a 1930's semi which is turning out to be a bit of a nightmare with sunken floors, wonky door casings, strange smells; to be honest beginning to wish she'd never bought it. But my immediate concern with winter approaching is the pointing. The front and side have engineering bricks with maybe 8mm mortar joins and it is really really crumbly. At some point it looks to have had red resin like material pushed into most of the joints which is failing in most places. So in the long term I will probably be pointing most of the building but in some joints the existing mortar is non existent (mainly the perps where a bay window meets the main wall) I can put a screwdriver right into the cavity and the gap starts thin at the front and opens up where the angle meets the wall. My question is how can I point these without pushing the mortar into the cavity as there is no back to push up against. Reasonably okay with the general pointing but scratching my head with this. Any help welcomed.

 

[^woody^]

Don't press so hard

 

[stuart45]

Try and push some against the sides of the brick in the perps with the pointing trowel first to build it up at bit at the back. Then leave it to harden up while you do the rest and fill in later.

 

[Argentum66]

Done a bit more research and it looks like these may be Accrington bricks that have possibly been pointed with red mastic at some point over the original mortar. Just trying to get the gaps water tight for the winter and can spend more time general repointing next year. Any thoughts on what to fill these larger gaps with in this situation? And going forward will it be best to replace the red mastic with red mastic or return to the original, presumably lime mortar?