17 replies to this topic

[Oscar]

Hi, I have a holiday home which is left empty for long periods. Every time I come back the walls feel damp and are covered in mould. I don't think it is rising damp, could be ventilation (or lack of it!). Does anyone have the same problem or an answer?

Thanks

[Ros21]

Hi Oscar,

I had the same problem winter 2007/08, when I arrived in March my bedroom walls were running with water & I had mould all over them. It not rising damp, as it was upstairs & not downstairs & is caused by condensation due to lack of ventilation.

This winter I have had someone check on the house every few weeks & air the place. I've just come back from there & I didn't have problems, so fingers crossed.

Ros.

[Laid Back Lil]

HI there, we too have problems and it's not uncommon in Crete - many people have damp problems. It's like Ros said though, it's usually due to lack of ventilation. We've got an ongoing problem, we have salt deposits coming through the plaster upstairs, and are trying to find out where the water in the cavity is coming from - bit of a mystery at the moment, as all the window edges, sills, door surrounds etc have all be resealed. We think it's a process of elimination and we'll get to the bottom of it eventually. The downstairs bedroom is the biggest problem - this is below ground so to speak and the walls have been tanked but the duvets get almost wet in there - this is because it is the coldest room in the house and we're looking into this. We have as a temporary measure put those moisture crystals in the bedroom and they take a lot of the moisture out of the air and fill with water quite quickly so they are obviously doing their job. These work out quite expensive in Crete though - I think the last two lots came to 26 Euros whereas it would be around 11 Euros to take 2 packs over from here. I suppose the long term would be to invest in a small dehumidifier but then you'll have the running costs of that. We have all the vents open on the house continuously and we are lucky that we have neighbours who regularly go in the house and open all the shutters and windows for us and give it a good airing. I don't know if you have central heating or not, but we are also looking into putting a timeswitch on the boiler and bringing the heating on for an hour in the mornings and an hour at night during the winter months. Will keep you posted on that. Good luck

[Wim]

This new old topic does run a bell but even the search button did not find the clapper

[Laid Back Lil]

Under 'Dehumidifer' in Living in Crete - and a fine response you gave me Wim!

[Wim]

That's me baby
Love me or leave me..

[Ton]

Most of the house problems associated with damp moulded walls are due to bad wall and roof INSULATION. Not only in Greece but everywhere.
To treat the mould buy a special paint available from your local paint store, to do a permanent fix insulate your walls and roof from either outside or inside.
Opening windows dehumidifiers etc they only treat the problem they do not fix it!!!
A cheap and quick method to insulate for dampness is to use on the external walls of the house and on the roof a material called in GreeK "MONOTIKO" it comes in big buckets and it looks like yougurt rather viscous material. If you are in the mood in the summer to do a bit of house work it can be fun. Hire first a low cost assistant to sand down and clean with a thick brush the walls and the roof. Then apply a coat of what they call in Greece ASTARI (some short of transparent primer) and then you can apply 3 coats of this Monotiko white colour viscous material. This solution will stop the moisture from getting into your house but it will not stop your house getting cold in the winter and hot in the summer. If you have a wet basement in the winter there iam afraid you have a rather serious problem which there is no cheap solution. You will need to excavate from the outside in order to insulate. If you would like a cheap solution the only thing which will resist moisture is a good tile glue which needs to be applied on the walls during the summer when the walls are rather dry.

[Wim]

Yes Denise, I found the one where it should be; in the "living in Crete" topic.

I copied that one as a quote herunder.

Hi Lil,



The first thing you have to know is how to tackle the problem. Is it simply the fact that this moist is caused by a too high humidity from within or from outside the house. If it is caused from outside it means that the wall and/or the floor, to put it simple, absorbs and transports moist which is absorbed by the air in the area which makes a high humidity value ( 90% e.g. is a too high value) and condensates which causes your problem. In this case you have to prevent the moist to let pass the wall/floor and the best way to this is to neutralize the problem, depending from the kind of the wall's material, by injecting it or (even better) by preventing it to come from outside if still possible.

If the problem is caused from within the house it simply means that this part of the house has not sufficient ventilation. Ventilation means in this case a constant air flow or draft from outside to outside. In a closed area the humidity in the air condensates and hence causes your problem.

A professional with the right equipment can measure this. 9 times out of 10 the problem is caused by the ventilation matter. Using a dehumidifier is an artificial way of solving the problem which, on the long term, costs you a lot of money (electricity) but solves nothing.

Painting the ouside wall like Ton suggest is also a possibility we do that a lot in Holland with houses that have massive (220 mm) outside walls. In that case you have to take care which kind of paint you use. I don't know if Monotiko like Ton suggests is what we call a "breathing" paint. Which means that it keeps down the moist from ouside but lets pass the moist from inside. Usually this paint is on a chlorine-rubber base.

Cheers

[Oscar]

I think I have now found the answer. I have found a company who supply and install solar powered de-humidifiers. As they are solar powered they cost nothing to run and will work every day even when I am not here. I also think the unit will provide some background heating in the winter months and possibly some additional cooling in the summer.

the web site is http://www.Solaair.com and the man to contact is Dennis

[Ton]

Some thoughts......

Sounds interesting but the presentation leaves open a lot of questions. The site info does not give technical data for how many cubic meters/room volume the system is good for. What happens during the night? Presumambly the system stops and the damp cold air accumulates again? Additionally in Crete during the winter the sun can only do a good job for a maximum of 4-6hours.

[Ros21]

One potential problem is, who is going to empty the water from the dehumidifier in your absence? I believe they have to be emptied almost daily.

In winter 2007/8 I bought a couple of the dehumidifier plastic boxes with crystals & put them in my house. When a friend went to check on the place these were not only full, but had emptied all over the floor!!! One of them was upstairs & I have a wooden floor & the water came through the ceiling. It is also the upstairs bedroom which is the biggest problem, and this was where I'd left one of these!!! I suspect that this also contributed to the condensation & mould that I had that year in that room.

Ros.

[Ton]

Ros, Oscar's solar solution does not require to take out the water from the dehumidifier. The dump air is pushed out of the house and replaced by dry air before it has a chance to condensate and create the problem. My concern though is that this system can perhaps work fine in a an area of 25 to 35 square meters with ceiling height of 2.5 meters. However for larger rooms it will be inefective since during the night the moisture which is entering the house from the non insulated walls will condensate and it will create the problem again. In brief I believe that this solution is a waste of money for areas larger than 35 m2 and its like treating a tooth decay with aspirins.

Ros to solve your issue with your dehumidifier plastic boxes you can insert a rubber tube at the bottom of the plastic container which drains the water outside the house via a house opening or a house drain tube.

[Oscar]

The unit I am having installed give a flow of 60m3/hr minimum (obviously during the day)and is suitable for a floor area of 70m2. I may have an aditional smaller unit fitted at a later date. It also claims to give a temperature rise of 30 degrees C - but we will see. Clearly it will not operate at night but then I don't have anything else that operates at night now. During the day it will work for nothing.

[Ton]

Oscar please give us a short report after you have the unit installed and tested.
thank you-Ton

[Oscar]

Will do

[Rampanthorse]

Do they have someone here to install it or are they coming from England?

[Rampanthorse]

hi Oscar
have the work done yet?

[stephen]

hi i am a newbee to forum
looking to move to elounda later this year and read the post about mould and damp problems.
I currently operate a thermal imaging machine that pin points leaks and damp in seconds, it also spot electrical problems and can scan houses from top to bottom in 2 hours
just wondering if anyone local offered a simular service?
would it be a viable business in and around elounda?
we could also offer a full repair and renovations service as ive been in property renovations for 15 years
any comments would be helpful
thanks steve