Damp problem

[Rosehill]

Hello

We have a holiday let which suffers from damp and mould mostly due to condensation caused by the guests as confirmed by a damp specialist.

we recently had a guest who suffered an asthma attack and complained about small mould and damp patches.

We have considered a dehumidifier but they need constant emptying, costly to run and are noisy. We would be grateful for any suggestions on how to deal with this issue.

Thanks

[newtimber]

I would expect your damp specialist to come up with a solution to the problem. You'll have constantly changing guests so they aren't all going to be drying clothes inside, not using the extractor fans etc.

I suspect it may be caused by the usage - the property is cold when no-one is there then heated up. the cleaners come round and leave everything damp and the house is then closed up and gets cold again. Increasing ventilation (trickle vents, extractor fans), increasing insulation and keeping a decent background heat would help.

You can get dehumidifiers that you attach a hose to so you can drain the water but it's not a good idea in an empty property in case the hose leaks,

[oasiscouple]

Perhaps you could consider the French system called VMC (ventilation mechanic controlée) used for many years in new build. It comprises low output permanent ventilation, usually in the roof space, with very small extract grills in each room connected to flexible tubing and an almost silent extract fan. Electrical consumption is very low and worth it to keep the property aired and dry.

[Drax]

From my experience of damp problems after renovating our 2 properties, one an old stone built house the other a more modern brick-built bungalow. The obvious one is to find out where the damp is coming from.
Our bungalow's damp problem was caused by a leaking roof (not always noticeable), tenants drying their damp washing inside the property and a lack of air bricks after fixing these and putting a rotary washing line up in the for guests to use, the damp problem was solved.
Other issues with regard to brick built properties are cavity wall insulation, which can cause internal damp problems and check whether the DPC (damp proof course) has been breeched.
With regard to our stone built house, damp was caused by a leaking roof (again) and earth piled up against a an external wall. These were fixed and the problem was solved.
Other issues with stone built houses are stone flags being replaced with a concrete floor. with a waterproof membrane to stop damp rising up through the floor. What happens though is that the damp travels up through the internal walls instead.
Also chimney flues being blocked up can cause damp problems.
The key to all these problems can be and is lack of ventilation.
Hope this helps.

[CSE]

Rosehill wrote about the damp issue last year.
viewtopic.php?p=366896#p366896
They have had a survey done.

[Rosehill]

Thanks for your responses. We already have a PIV drimaster in the roof which helps with the upper floors but the lower floors still suffer from condensation which has been confirmed by a damp specialist. They suggested keeping the windows open to increase ventilation but it’s not something we can ask our guests to do.