Water problems in UK are not uncommon and there are many ways that it should be dealt with. I can understand that it may not be very straight forward for some to see that they have a water damage on their walls and carpets.
I can see in many houses laundry being dried in the rooms where windows are closed and it is just cold in the house, how many households have furniture close to their clod walls that simply produce moisture drops that will with time transfer to fungus and other interesting living beings.
What is best in cases like that is obvious and should be applied immediately, if it is not obvious then I will outline it for you. Do not have clod room with laundry in room. do not have furniture close to clod walls. Other then that one can always place moisture traps, they can be bought cheaply in supermarkets and those are grate inventions that will save you lots of lung conditions and money on renovation your property and simply great comfort of living.
I had same problems myself, frankly no moisture traps are bought yet. But I do certainly have my furniture farther from wall and no wet clothing in my room at any time.
This is amazing place to be leaving at and one should visit Barry at least once in lifetime if you are living in UK, however not only this place is amazingly lactated and with many great community it has some serious issue with clod walls and obvious moisture. There is much research and common sense knowledge showing that moisture is causing mould on the walls and in the air, it is not that we don’t have mould spore in regular house and it is only occurring at those seaside places. Mould is very effective leaving thing that will utilize every possible space it can and as much food as it can consume and convert in to energy will be utilized.
For those spore to develop in to mould many conditions has to be actually in place, first of all there needs to be enough humidity in the house and not enough air circulation to make the spore circulate in the air rather then stay on the surface and start eating organic matter. That is why it is strongly recommended to have air dehumidifiers in the rooms that one is experiencing some mould development, besides that you can always clean your walls with dettol or other disinfecting substances that will help to fight spores that are very origin on mould structure in the house.
Unfortunately Barry and Cardiff is presented with lots of moisture in the air, not because of all the rain that we have in Wales.
Using passive dehumidifiers and cleaning your walls with domestics or other strongly antibacterial solution will help to fight spores that are main cause of mould development on the walls, when it comes to carpets one should be careful with use of any strong antibacterial chemicals as those can damage carpet irreversibly. Best of luck with your fight.