Damp on external wall old property

mutty_hc

Thanks FreeBear

Yes, I meant kill the root itself with some killer

Indeed, lots of grunt work to do currently.

Would you consider airbricks and ventilation around the property worth considering to (e.g. extractor fans in kitchen etc?)

FreeBear

mutty_hc wrote: »

Would you consider airbricks and ventilation around the property worth considering to (e.g. extractor fans in kitchen etc?)

There should be an air brick every eight feet or so to ventilate the void under the suspended wooden floor. Having a concrete slab in one room may well have messed up the cross flow of air under the floors in adjacent rooms. Ventilation of the under-floor void will help keep damp under control and minimise the risk of joists rotting.

Extractors in bathrooms & kitchens are generally a good idea. A decent extractor hood over the hob/cooker venting to the outside will pull much of the smells & steam from cooking out. Same for the bathroom. In an old house, there is rarely a need to fit air bricks to the walls to allow (cold) air in to replace air being extracted. If you were thinking of going that route, I'd suggest looking at MVHR systems. But save that for another day - It isn't going to help with the current damp problem.

mutty_hc

Some exterior pictures of the property after removal of earth today.

https://ibb.co/nkXWsx2
https://ibb.co/zH3vF7D
https://ibb.co/CH4rYbJ
https://ibb.co/gD0nkQD
https://ibb.co/P5h7NBM

We dug out a hefty amount of concrete, there was a huge amount right up next to the property in both areas which are suffering from damp.

The exterior picture which shows some brick missing has seemingly been like that for a long time, lots of plant roots going in to the property there which we are going to take back.

Will fill the area with pea gravel to create a french drain, will hopefully help somewhat.

mutty_hc

I'm thinking we might need parts of that wall repointing, particularly the area affected by the roots?

mutty_hc

Further investigation - chipped off damp gypsum last night to reveal lime plaster which feels dry underneath?

Wall will need a replaster for certain as it is so old.

FreeBear

If you're up for doing the job yourself, Ty Mawr do a series of short videos showing the stages of lime plastering - https://www.youtube.com/watch?v=DmWQ1X1jYOk&list=PLFSqOXpgBEL7HsP_j3HQv1YQzwrbhJDLi (just posted on another thread, so had the link to hand).

cardude

Hi All,

I thought I'd update this, I have left it now 6 months since taking it all back.
Gravel French drain has been in since late November (therefore throughout the worst of the rain we've had).

I took off the gypsum skim layer and have left the wall since. At first the wall was 'cold' in areas which were previously damp, however, since then it has dried out and there has been zero signs of damp on the wall. There were some signs of salts when I chipped off the gypsum layer, but this has not returned and I have been particularly observant since. Both areas of 'damp' were localised to areas whereby there was significant soil/ damp on the external part of the property which has now been remedied.

Therefore I am nearing a point of considering next steps with the wall, I am debating two options here really.

a) take off lower layer of gypsum around the external wall, reskim with a lime plaster mix not worrying about the layer being too clean, go over with an insulating paper and then a good quality wallpaper, paint with a breathable paint

b) take plaster back to brick, consider fitting plasterboard but ensuring it is done properly (this will probably not be until 2021 given current circumstances) 

in both events I will repoint areas to the external property, but the french drain seems to be doing its job. I have since dug one in around the entire property.

What I cannot work out is that at the base of the wall in certain areas there isn't plaster, but instead what looks to be concrete (or possibly limecrete) and I can only think when the fireplace was put in part of the plaster came off and was then repaired but a previous owner. Either way, this too is dry.

Thoughts on the above?
Thanks.

FreeBear

Once a wall dries out, it will always be warmer. Water is pretty good at sucking heat out, which leads to cold spots where condensation forms - Ends up being a vicious circle.

As to what to do with the wall - Don't put up insulated wallpaper. It will form a waterproof barrier and you'll end up with a cold, wet wall again. If you want to insulate, do the job properly (look up warm batten insulation), pay attention to leaving an air gap between the brick & insulation, and ensure there is adequate ventilation. Alternatively, cork & wood wool boards finished with a coat of lime plaster.

If you are just going to replaster, then remove as much of the cement render as possible, and do a two or three coat lime plaster.