Damp proofing old house but found breeze blocks!

If the section of wall is new, there may be a plastic damp course installed. Does salt affect that area of wall too, or are there any obvious signs of damp? If you're injecting cream, it goes into the mortar course, but check what's already there first.

Here's a version without hyphens, more conversational: --- Before you touch that section, I'd be questioning whether "rising damp" is even the right call here, or on the rest of the house if I'm honest. It's massively over diagnosed, and injection cream plus membrane gets used as a default when the real cause is often something else entirely. Could be hygroscopic salts pulling moisture from the air, a bridged DPC, penetrating damp, or a dense modern render trapping moisture that the wall would otherwise just breathe out. The breeze block bit is a good example of this. Rather than working out how to inject it, I'd be working out what's actually causing the reading there in the first place. Take proper readings across it and into the original wall either side, and if you can, get a sample tested for salts rather than trusting a moisture meter alone. Salt contamination will give you a false rising damp reading forever, and injecting or membraning it changes nothing because it was never rising groundwater to begin with. Even if it does turn out to be genuine ground moisture, I still wouldn't jump straight to tanking or membrane. That's masking it, and on an old building it tends to just push the moisture somewhere else instead of dealing with it. Better to find the route it's actually taking, whether that's ground levels, sub floor vents, or external render and pointing, and sort that at source. Only fall back on a physical barrier if there's genuinely no other option. So before you buy anything else, figure out why that block panel is there, get proper readings and a salts test if you can, and don't assume the diagnosis for the rest of the house automatically applies to this bit just because it's easier.