We have a holiday home in Western France which consists of two 19th century stone properties. It’s left standing empty for most of the year, and is used mainly in the summer months. The main house doesn’t have any problems really, it smells a little musty and we get the occasional bit of damp coming through one of the walls by the window but nothing that you wouldn’t expect from an old property that is unoccupied for most of the year. The problem lies with the guest cottage/gite. When we initially got the keys to the house, we immediately noticed a very strong damp smell in there as well as an absolute bitter cold. At the time, we put this down to the fact that there hadn’t been anyone in it for a month, and thought it just needed a good airing. But the smell didn’t go. Last October we had to take up the floor in the kitchen area (it’s open-plan) as they had used these lino-type floor ‘tiles’ that were laid on chipboard. It was so damp that the lino had started to lift up and all the chip board underneath was damp and mouldy. When we lifted the floor we noticed that the soil underneath was stacked against the joists, meaning there was no airflow. The soil was bone dry though, much to our surprise. We thought we’d found the route of the problem, we levelled out the floor creating a space between the joists and the ground, so that it could breathe. We purchased a dehumidifier which was left on constantly for around 2 weeks, and warmed the property using the log burner. At the end of the two weeks, you could tell that the air was much drier, and the damp smell had disappeared. We then came back to the UK, so the gite has been left standing for approx. 3 months.
Our caretakers went in this week to open up for renters, and the property was very very damp, worse than it’s ever been. The linen upstairs was wet, there was mould growing on the wooden utensils in the kicthen, along the wooden pannelling, mould had also attached itself to some decorative boxes I have upstairs, hanging off mirrors in big strings, it was bitterly cold in there, you could see your breath in the air….you get the picture. So we are now perplexed as to what is causing this. The floor underneath has been checked again and it’s totally dry, so it’s like the damp is there in the air not rising from the floor. When we had the floor up, we checked everything for leaks, but there was nothing. After doing a bit of research I’ve read that chemical injections as a damp proof on old stone properties are not practical and can do more bad than good. So we don’t know how to deal with this problem. Obviously when we go over in March, I can dry it out with the dehumidifier again, but it’s not going to solve the problem when we shut it up again. Like I already mentioned the main house is made of stone too but it doesn’t get this problem. The only difference between the two houses is that the gite has double glazing, whereas the main house has the original windows. Is there a chance that the double glazing could be causing the cottage to ‘sweat’? Again, I ‘ve read that double glazing is not always practical for old buildings as it doesn’t allow them to breathe. Any suggestions or guidance would be greatly appreciated.