Repointing 1930s solid wall property

[danlightbulb]

Are you sure it's a solid wall? Stretcher bond usually suggests it's a cavity wall, although not always.

Definitely solid wall. There's a header course but it's only every 5 or 6 courses rather than every 2nd course in older houses.

IF you can get NHL3.5 locally and you're happy to mix your own mortar, then that would probably be the cheapest option and would be highly unlikely to cause any issues at all. That's what I'd do if I were looking to save a few bob.

If you're feeling a bit flush, then a premixed NHL2 mortar would be the overall best option in my opinion.

It's really annoying because the manufacturer packaging says NHL2 is for 'sheltered' applications or internal work, and that NHL3.5 is suitable for external pointing. But this contradicts the other advice that NHL2 is the better choice.

If I could get NHL2 locally I'd probably use it but I can't.

Also can I trust the NHL3 locally as it's not St Astier?

Absolutely agree 100% with @stuart45 post. Hot lime is the gold standard for “really old” properties, my mental measure is pre-1850s for that sort of thing. Failing hot lime, like putty based mixes are usually the way to go.

Later than that there’s very little that a good NHL2 based mix won’t solve.

Up above I mentioned mixing NHL3 with lime hydrate. You said that was ok but you doubled the sand dose as well which means I still have a 1 to 3 mix. Why would you not add hydrated lime to NHL3 and keep just 3 parts sand? Wouldn't this improve the lime content and make it more like an NHL2?

 

[a twig]

Up above I mentioned mixing NHL3 with lime hydrate. You said that was ok but you doubled the sand dose as well which means I still have a 1 to 3 mix. Why would you not add hydrated lime to NHL3 and keep just 3 parts sand? Wouldn't this improve the lime content and make it more like an NHL2?

It would absolutely improve the lime content but my thinking was that you might then struggle more with shrinkage and hence my preference for upping the sand.

If you were so inclined you could give both a go and report back with photos after a couple of months and let us know?