Damp wall - good case for injection?

Not when one has central heating. It doesn't stop condensation being a major issue.

Tis if you have a single brick outside wall..especially in a bathroom or kitchen.

Much rarer with insulated walls these days..but on older properties..

Another cause of this is badly designed heating layouts, where if you were to imagine the house will all the internal walls are floors removed, the radiators are left bunched together in the middle (least pipework) rather than mainly spread around the perimeter where they should be, resulting in uneven heating.

I had a number of areas of very mild condensation in my 9" brick house before installing central heating (house used a number of individual gas wall heaters, but nowhere near as many as there are now radiators). The areas of condensation were very good hints where radiators should be positioned, and by using this technique, there's been no condensation since.

It was said in Victorian times that if you gave the peasants a bathroom, they'd only use it to store coal. The idea that council tenants put wet washing on radiators seemed in a similar vein.

My mother does that to this day.

I hope she's not in a smokeless fuel zone.

Christian.