How to turn a lovley old house with solid walls into a warm efficient home




The south facing wall, which takes the brunt of the weather was patially rendered. This render was in very poor condition. It was heavily cracked, and obviously allowed rain to penetrate behind the render. I planned to remove this render and, because I suspected that the bricks might not be in graet condition once the render was knocked off, I planned to have it re-rendered - this is covered in another article.The old part of my home is made of solid 9" brick and has no damp proof course. I would not say the house has an issue with damp, certainly not rising damp.

I planned to lay a new solid ground floor including a DPM, into which I would install UFH. With the floor unable to 'breathe' it is possible that such action may increase dampness in the walls. Because I did not feel that dampness was a paraticluar issue in my home I decided that this was the best course of action. However as the floor would have a DPM it made sense to install some kind of damp control into the walls too.

There are many injection creams available on the market these days for DIY installation. Holes are drilled into the mortar line and the cream is injected. Over time, the cream soaks into the mortar line and forms a barrier to prevent moisture from rising up the wall - or so the theroy goes. I did my research about these creams but in truth I think it is hard to get a definitive answer regarding their efficacy.

In very thick, irregular stone walls which may even have a rubble infil it is possible that any injected cream coudo just puddle into voids within the wall and not disperse as intended. It is also possible with such irregular walls that there is no continuous horizontal line of horizontal. In such circumstances I would question whether cream injection would serve any purpose.

My house being of brick construction, with no internal void and with an obvious and continuous mortar line I felt that injection into my walls would be beneficial - though its unlikely to be perfect.


injected damp proof course, eco renovation, house, homeThe process of installation is quite stright forward. Using a 12mm long masonary bit holes are drilled into the mortar line to almost the full depth of the wall at 120mm spacings.

Using a standard skeleton gun the cream is injected using a long nozzle. The nozzle is slowly withdrawn as the cream is injected into the hole.

damp proof cream injection, eco home renovationThe hole can then be capped off with a little mortar.


© Christopher Thompson