Damp patches on my walls

I can only assist with advice, but only after this on-going situation. I can assist with a professional (Sax family Spanish construction company) but are now in lockdown. Feel free to contact by PM at a later time.

V

Many thanks. I will

Cheers Graham

From my guide to paint:

Transpirable - Breathable. If you're painting walls subject to rising damp, sealing the surface with ordinary paint will result in the rising damp forcing that paint off. If you use a breathable paint then the moisture can escape without forcing off the paint. I don't doubt there are several makes on the market, but the ones I've come across are both by Titan - Orion fachadas plastico A4 Titan profesional, and Titan pintura antihumedad D14.

It's no good dry lining the walls without solving the problem first, the plasterboard will just get damp and fall apart as you will just be hiding the problem temporarily.
Most of the problems we had were immediately solved by installing central heating, expensive, I know, but it worked. We had a few other problems with the tiled surround being defective and having to dig it up in places where it had just been laid on bare earth with about an inch of cement underneath. We have also redirected down pipes so they empty away from the house. Only when we had solved the damp did we put insulation sheets on the external walls and plaster-boarded over which all helps to keep those walls warmer.
Damp is a huge problem everywhere so I wish you luck.

The plasterboard won't get damp if the job is done correctly, did my whole house nigh on 18 years ago and never had one sign of damp since, need to make sure you use someone whom actually knows what they are doing, and not just an easy jet got of the plane i'm this i'm that supposed builder. Go and see similar past work that has been carried out by whom ever you may choose to do the job. Talk to the house owner see if they were happy with what has been done, how long ago was it done etc etc, use your brains, or you will be had over.  The reason there is damp, is because old and some new Spanish buildings don't have damp course. 

If it was condensation causing the damp then dry lining will solve it because the walls will not be so cold. If it is penetrating damp then dry lining will only be a temporary solution as the damp will penetrate the plasterboard sooner or later. For example, the grouting of the tiled skirting around our house had perished and water was soaking into the wall. If we had not made good, the water would have continued to soak through. In some parts there was very little concrete under the tiles so we dug it all out and started again and in another place one of the red bricks with holes had been used to "fill a gap" in the blockwork with the holes going from outside to inside, if we hadn't solved these issues then no amount of dry lining would have stopped it.
It is not just the lack of a dpc, it is the single skin walls and lack of insulation that cause many other problems.

Sorry, you are wrong! I know exactly what I am talking about and have arrested damp ingress here in Spain many many many times, if its condensation, an air brick or two in the correct places will alleviate condensation. If its rising damp, that is coming up through the walls, per no damp course, this is a harder fix! You can do one of two things, you can either excavate round the walls of the house, cut into the wall below ground level and feed a membrane in, then tank it out. Due to the fact that houses in general here do not have a cavity, you can not inject the walls as doing so to a none cavity wall has a  very short term effect if any. The other way, is with wall board, but there is a professional and correct way of doing this. Personally I have done both of the above more than a few times for friends and  each way have arrested/ stopped damp ingress. In the UK, I was a plasterer for many many many years, obtaining both a citing guilds and master craftsman  certificates. Indeed as I say, my home was infested with damp when we first moved here some nigh on 20 years ago, but come into my home and you won't see any damp what so ever.  

Hi

When you say wall board are you referring to p/board? If so is it foil backed?

Do you dot and dab or fix timber battens to accept the board?

The problem with aluminium backed plaster board is if the rising damp is alkaline, in which case it will soon erode the aluminium.

Dot and dab is an easy way of fixing plasterboard, but I prefer timber battens to give a bit more air space. Having fitted them, cover with heavy duty polythene sheet, stapled on. Then fit the plasterboard, with some louvres top and bottom to allow the damp to escape.