Hi to all

Just arrived at our place in Moraira, not been for 6 months it's the longest we have been away sinse we had it built 5 years ago. Never had a problem with damp on any walls but this time there are two areas approx approx 1 foot above floor level and spreading approx 4 feet along the wall. This is on an internal wall so we are putting it down to humidity/ condensation. The question is how can we prevent this in the future, we leave a dehumidifier on, set at 60 percent. Also we have tried drying the wall out but it has left a stain, should we paint over it or chop off the plaster. Any advice would be appreciated.

Thanks in advance

odd that it's on an internal wall, especially with a dehumidifier running - are there any water pipes running in it

the best way to get rid of a damp stain is to wash it with weak bleach solution - if itis so bad that it has bubbled then of course you'd need to rub it down etc.

I think it all depends what the internal walls are build on. In UK, they are built (generally) on a slab of concrete which has a damp proof membrane - it's not necessarily the same in Spain.

I know my buildings are a little older, but the internal walls here are (effectively) laid on bare earth with no damp proofing. We get damp coming through all the time and there's not much we can do about it.


Having said all that (doom and gloom), I suspect in your case that it could be down to poor ventilation in that particular area. What you are doing sounds reasonable - welcome to Spain!

If you look closely, most homes and public buildings have damp patches. In the UK one would be extremely concerned but in spain the locals don't regard it is an issue.

I've just cured the same thing. Water pipe leak under the floor is my guess running from the shower(s).

Wow - do you have a crystal ball

I have damp in my basement apartment, internal walls again - what's the problem?

Hi
No leaks from pipes etc, think it has to be humidity, or cold bridging, how can we prevent it happening in the future?

Would give you best guess if I had a look at it and the surrounding rooms.

Given that the OP's property is only a few years old and presumably has a damp course, the natural assumption (I know, can be the mother of all Fukc-up's) is an internal leak either under floor or along edge of walls, depending where the water pipes are running.
The one I have just done had a two fold problem, bad grouting at the base of both showers ( both backing on to my bedroom wall) and next bedroom's shower, the down pipe from the shower had come loose and was leaking onder the concrete floors. Just like the OP's problem, the wall was damp in a long and upward spreading patch, but is now cured.
Now, please go to the back of the class, sit on your hands for an hour and let the adults discuss the problem and hopefully we (the adults) can help the OP can move forward.

Are there any wash basins or showers backing on to the wall Bil and do you have a damp course?...or any known water pipes (toilet outlet etc)running near by?

We had damp in one bedroom where the wall joins the ceiling and was pretty sure it was caused thro condensation. Washed the walls with a bleach solution and then painted with a special paint recommended to us by the assistant in Leroy Merlin. That was four years ago and its never been back since although we now keep two small damp absorption thingys we bought from Mercadona and replace the crystals once a year.

I do hope Bil's problem is as simple to cure....much easier all round.

Riggy
No water pipes or waste pipes in the couple of areas of damp.property only been built 5 years and as you would expect there is the required dpc. The property has quite an extensive under build so is above ground level. I was thinking along the lines of cold bridging where the cold floor comes into contact with the plastered wall causing a cold spot then humidity condenses leaving a water stain. But if this was the case why has it taken 5 years to happen?
If we paint on damp repellant will that just move the problem to another area?.
Thanks in advance

Hi Bil, a myriad of things to consider, but as the house isn't going to fall down this week don't fret about the damp patch, unless it gets really bad.
So, other forumites have experienced damp patches, usually one-off (hope yours is as well) and cured them by various methods and their advice may well come into it's own at some stage. Personally, I would keep brushing it off untill you are satisfied it has completely dried out and no sign of it spreading or indeed returning, then rub down and paint over with a sealant as has been suggested.
Just some questions, what is above this internal wall, another bedroom, a loft? Is the damp patch any where near an external wall?
Does the damp patch start above floor level or has it spread to "one foot above the floor"?
I'm playing detective here as I can't see the problem any chance of a picture in relation to the room/nearest window etc?

Hi Riggy

IPad for some reason won't let me send picture, will have to sort that out after damp patch; damp patch starts above the skirting tile , when I say internal wall it is actually an external wall but set back under a porch with glass curtain front so rainwater would not get to that area of wall.
Keep thinking it has to be cold bridging and condensation.
Will paint on water repellant paint and see what happens.

Aha! I'll put a fiver on a leak from the porch that you can't see..........bit of pointing, flashing or nail hole or something letting it in..........