[Kikie]

How far south in Spain do we have to go to avoid high humidity levels in Spanish houses? The hygrometer in our present house constantly reads high 60s to low 70s, even when outside is reading much lower, despite the house being a newish build.

My health is suffering from this and any hidden mold, particularly aspergillus, is a danger to my partner. Dehumidifiers will only help a little.

 

[davexf]

Hola

I live in the Cádiz region and it is very wet here - my weather station will help you understand

chiclana weather station meteo tiempo forcast

Davexf

 

[Overandout]

I know of people in Madrid with damp problems in older properties.

I think the quality of construction is the overriding factor for damp in the building, but of course the air humidity outside depends more on geography, but not so much on latitude, but on other factors such as altitude, distance from the coast etc....

 

[xabiaxica]

Probably the Canaries......... more settled temperatures & I believe low humidity

All of mainland Spain gets cold & damp.

 

[Overandout]

The yellow / orange areas are this with lowest RH (yearly average).

So, xabiachica is correct with the Canaries being the driest, but only the larger islands and away from the coast.

 

[baldilocks]

Damp in most houses arises from two sources and has different methods of transmission and treatment. Very few houses have a damp-proof course in their walls or under the floor, so they suffer from rising damp this manifests itself in the walls of the ground floor or lower. Many properties have little proofing against rain penetration through the walls. In 2009 we had a lot of rain and the water was coming through, then running down the inside (note - this was not condensation,) in addition, this also makes the walls very cold so any airborne dampness in the house condenses on the cold surface.

How to deal with these forms of dampness.:
1. Cover it up: When we bought our house, the walls on the ground floor had some horrible plastic cladding up to a metre from the floor. We have seen other houses that have tiles half way up the wall which can be quite attractive but they are only to keep the damp in the wall and stop it coming to the surface where it forms moulds which are both unsightly and unhealthy for the occupants. We removed the ugly cladding, cut back the affected plaster and painted the wall thoroughly with PVA (poly vinyl acetate = Unibond which is difficult to get in Spain so we used white glue (same stuff) diluted 2:1 with water to make it easier to apply and painted the walls up to a metre with this solution, left it to dry, repainted and again left it to dry; Replastered the wall using ready-mixed filler, then painted with plastic emulsion - end of problem. The damp is still in the wall especially the lower parts but the PVA acts as a barrier and prevents it coming to the surface.
2. Keep it out: Outside walls on the lower and upper floors can suffer from rainwater penetration which is made worse by the fact that the paint on the outside is frequently "Cal" (whitewash.) What is required is for the outer surface to be hacked back and resurfaced with "Capa-fina" which forms a water-proof barrier on the outside of the wall. The Capa-fina is then over painted with plastic emulsion (pintura plastica) which will last at least seven years unless you are in a very exposed location. Allow the wall to dry out; paint the inside of the wall where the dampness was with PVA diluted as before (this is to prevent any salts in the wall drawing any moisture in the wall to the surface, then paint with pintura plastica. These should stop you having a damp house unless, you are in the habit of allowing steam from the kitchen/laundry free access to other rooms.

 

[snikpoh]

Damp in most houses arises from two sources and has different methods of transmission and treatment. Very few houses have a damp-proof course in their walls or under the floor, so they suffer from rising damp this manifests itself in the walls of the ground floor or lower.

Did you know that the use of a damp-proof course (plastic strip in wall) is against building regulations in most (all?) of Spain. I was told this is because we are in an earthquake zone and the house would simply 'slip' off the foundations.

Myth or truth???

 

[baldilocks]

Did you know that the use of a damp-proof course (plastic strip in wall) is against building regulations in most (all?) of Spain. I was told this is because we are in an earthquake zone and the house would simply 'slip' off the foundations.

Myth or truth???

I have heard that before and, I guess it is feasible, but they could use what they used to use in UK - slate.

 

[Overandout]

Did you know that the use of a damp-proof course (plastic strip in wall) is against building regulations in most (all?) of Spain. I was told this is because we are in an earthquake zone and the house would simply 'slip' off the foundations.

Myth or truth???

Total myth.

I was asked by a British Building Surveyor if this was true and I helped him by looking into the building regs here.

In fact, in certain circumstances (depending on foundation design, materials used, groundwater table depth) it can be obligatory to use a physical membrane in Spain.

If I remember I will look up the building codes. I think I kept them somewhere.

What is true is that it is not common here as the circumstances which make it obligatory are not common as they are in the UK.

 

[snikpoh]

Total myth.

I was asked by a British Building Surveyor if this was true and I helped him by looking into the building regs here.

In fact, in certain circumstances (depending on foundation design, materials used, groundwater table depth) it can be obligatory to use a physical membrane in Spain.

If I remember I will look up the building codes. I think I kept them somewhere.

What is true is that it is not common here as the circumstances which make it obligatory are not common as they are in the UK.

The building regs are in the FAQ - I posted them there a couple of years ago.

 

[VFR]

Damp in most houses arises from two sources and has different methods of transmission and treatment. Very few houses have a damp-proof course in their walls or under the floor, so they suffer from rising damp this manifests itself in the walls of the ground floor or lower. Many properties have little proofing against rain penetration through the walls. In 2009 we had a lot of rain and the water was coming through, then running down the inside (note - this was not condensation,) in addition, this also makes the walls very cold so any airborne dampness in the house condenses on the cold surface.

How to deal with these forms of dampness.:
1. Cover it up: When we bought our house, the walls on the ground floor had some horrible plastic cladding up to a metre from the floor. We have seen other houses that have tiles half way up the wall which can be quite attractive but they are only to keep the damp in the wall and stop it coming to the surface where it forms moulds which are both unsightly and unhealthy for the occupants. We removed the ugly cladding, cut back the affected plaster and painted the wall thoroughly with PVA (poly vinyl acetate = Unibond which is difficult to get in Spain so we used white glue (same stuff) diluted 2:1 with water to make it easier to apply and painted the walls up to a metre with this solution, left it to dry, repainted and again left it to dry; Replastered the wall using ready-mixed filler, then painted with plastic emulsion - end of problem. The damp is still in the wall especially the lower parts but the PVA acts as a barrier and prevents it coming to the surface.
2. Keep it out: Outside walls on the lower and upper floors can suffer from rainwater penetration which is made worse by the fact that the paint on the outside is frequently "Cal" (whitewash.) What is required is for the outer surface to be hacked back and resurfaced with "Capa-fina" which forms a water-proof barrier on the outside of the wall. The Capa-fina is then over painted with plastic emulsion (pintura plastica) which will last at least seven years unless you are in a very exposed location. Allow the wall to dry out; paint the inside of the wall where the dampness was with PVA diluted as before (this is to prevent any salts in the wall drawing any moisture in the wall to the surface, then paint with pintura plastica. These should stop you having a damp house unless, you are in the habit of allowing steam from the kitchen/laundry free access to other rooms.

So to summarize you removed the cladding (that the vast bulk of Spanish houses have) and replaced it with plastic emulsion (liquid cladding) inside & out.

https://youtu.be/Ck7RGBkxy8k?t=89

 

[baldilocks]

So to summarize you removed the cladding (that the vast bulk of Spanish houses have) and replaced it with plastic emulsion (liquid cladding) inside & out.

If you can't be bothered to read the post properly and without preconceived ideas, it's not my fault.

 

[VFR]

If you can't be bothered to read the post properly and without preconceived ideas, it's not my fault.

I read what "you" wrote.

 

[Pesky Wesky]

It seems to me that the local geography has a lot to do with dampness but little to do with how far south you are. For me Nerja was one of the worst places I have ever visited because it was in the summer and the humidity was unbearable. That's probably because I've spent 30 years living in the very dry area of the Sierra de Madrid. Where I am there is very little damp, I'd go so far as to say none, but Over and Out lives in a different area of Madrid and says he knows people who suffer from damp in their property so I think it's a very localised problem. I do know that near the coast there is logically more damp. I have noticed it in Formentera, Valencia, Tarragona, Nerja, Torrevieja and funnily enough not so much in Bilbao, but it's probably noticiable in older properties

 

[Alcalaina]

It's more to do with construction than location. Our house, built in 1988, has no damp. Others in the same street have damp coming through the walls every winter and are constantly fighting black mound. They are old townhouses with walls 2 or 3 feet thick made from mud and rubble. Ours is made from concrete blocks with plenty of airbricks.

Good ventilation and prodigious use of bleach is is the best solution. Always moisten mould with bleach solution and leave for half an hour before scrubbing it off. That way you won't spread live spores.

 

[Europa47PG]

When I lived in an old townhouse in a village just outside Granada we had damp patches and there was no rhyme or reason as to where they appeared, it drove me mad but when I mentioned it to the locals they just shrugged and said that was just part of living in an old property. When a house was being built on a plot of land a few streets away I was staggered to see they didn't put a damp course in and that was only 5 yrs ago. I went through bottle after bottle of bleach....in the end it got the better of me and I sold and moved on to a property that didn't suffer the problem.

 

[davexf]

Hola

As was said, "Ventilation is the key" - I use a dehumidifier 24 X 7 from now until April and don't have a problem with mould - but I use portable gas heaters which need dehumidifiers.

Davexf

 

[bob_bob]

Dave, as I'm sure you know (but others may not) that portable gas heaters throw out a lot of water as a byproduct of the gas combustion process with heaters with no access to a flue... you may as well spray water on your walls; hence the need for a dehumidifier(s).

In Spain you need 'dry' heat such as gas central heating or electric heating, if you have a good source of well seasoned wood then a wood burner will work well.

 

[davexf]

Dave, as I'm sure you know (but others may not) that portable gas heaters throw out a lot of water as a byproduct of the gas combustion process with heaters with no access to a flue... you may as well spray water on your walls; hence the need for a dehumidifier(s).

In Spain you need 'dry' heat such as gas central heating or electric heating, if you have a good source of well seasoned wood then a wood burner will work well.

Absolutely correct - Even my log effect gas fire gives water out while burning. And when the house cools, condensation is a problem unless you take positive steps to deal with it.

Electric heating is expensive when compared to other types of heating, but everyone should be aware of the need to avoid mould

Davexf

 

[thrax]

Well where we live a damp proof course is illegal but it does vary depending on where in Spain you are. I believe Almeria is the least likely area to be affected by damp and humidity in Southern Spain.