When condensation and mould is caused by the tenant?

Don't mess about with them s21 while you can and let it to a tenant who will respect and live in the property has it was built for , ie warm well ventilated and regularly cleaned and inspected.

I share and feel your pain. Some years ago I had a young mum renting one of my modern well insulated houses. I had coached her about ventilating the house and keeping it warm. She had a small baby so there was masses of washing which she dried indoors. She complained bitterly to the managing agents about condensation and mould I attended a site meeting and the tenant's rather aggressive dad turned up, effing and blinding, threatening to report me to all and sundry. I patiently sought to explain how moist air will condense on cold surfaces if it is not allowed to escape. Thankfully the tenant left soon afterwards and I have had no issues since, although I did need to redecorate.

Houses need to breathe. The problem is that energy costs discourage tenants from using the heating and it is always seen as the nasty landlord's fault.

I hope you find a solution. I have no advice to offer that has not been given already by others.

Reply to the comment left by Des Taylor & Phil Turtle, Landlord Licensing & Defence at 24/01/2024 - 11:56
Not if a tenant is not using the correct ventilation equipment that's supplied in the property ? If it still is the landlords responsibility we'll its best the landlord and tenant part company.

Reply to the comment left by Reluctant Landlord at 24/01/2024 - 11:05
I think you will find that a humidistat extractor in a bathroom will have to have a cord pull switch in the room and an isolating double pole switch on the outside of bathroom, most are fitted above the door out of easy reach.

Sometimes you DO have to tell people to suck eggs but after that it is their responsibility to look after the house they are renting is it not ?

The fact is that many of our buildings were designed in the nineteenth century, when occupants used to go off to work at the crack of dawn, crawl wearily home after dark, use the outside toilet and go to bed. They'd bathe in a tin bath in front of the single fire in the property on a Saturday, whether they needed it or not.
Now people demand central heating, indoor showers and toilets, and can stay at home all day, working or not. All of this generates huge quantities of the warm, moist air which causes mould. My maintenance engineer installs plastic tubes, with a grill cover on each end, between the bedrooms and the loft space.This greatly reduces the problem

Reply to the comment left by Jason at 24/01/2024 - 09:29
I watched most of Martin Lewis program on 23 rd Jan (last night) and thought it was slightly biased that Shelter were there without somebody representing the Landlords. It seemed to be a great free plug for Shelter.
Anyone else have any thoughts ?

I’m a Chartered EHO and portfolio landlord. One property we rent is a ground floor flat (cooler than other floors). Over the last 13 years we have probably had 5-6 tenants. All were given the same advice regarding avoiding mould build up. All had no issues except one - who complained to Environmental Health. When I explained my experience and knowledge and that the mould issues were caused by not using the heating enough/ not using the dehumidifier/ not using the window trickle vents / not tackling any visible mould when it first appears / drying clothes indoors etc then the EH Dept backed off. Another tenant has been in for two years since then and has no issues as he’s heeded the advice.

Reply to the comment left by Reluctant Landlord at 24/01/2024 - 11:05
In window humidistat fans are quite common - a google search will throw up several brands and suppliers of such.

The issue is that electrical regs require them to have an isolator switch so your tenant will still be able to disable it if s/he wants to. What you probably need is a monitor/data logger that records when that happens - again, google is your friend.

Hi, Im a Chartered Building Services Engineer by profession. Condensation has become a much greater problem as buildings have become more air-tight, preventing the natural flow of air and the removal of moisture. Back when I was a child, we had a coal fire in winter which constantly drew fresh air in to the house and sent it up the ruddy great hole that every house had in it, called the chimney! Lack of heating is often cited as a "cause" of damp, but this is not the fundamental problem. Water, either from drying clothes, cooking and showering, or simply from the 200g of water we each breathe out overnight, has to go somewhere, irrespective of the temperature in the building. (It is a fundamental law of nature that matter cannot be created or destroyed- if you have a litre of water in the air in a room, it will remain there in one form or another until it is removed.) Again, back in the days when we had single glazing, the water in the atmosphere used to condense on the coldest surfaces, which were the single glazed window panes. We used to wipe the puddles of condensation off the window sills in the morning, which effectively spared the other surfaces. Now the walls themselves are often as cold or colder, and the moisture will condense on those surfaces. Warming the room will actually increase the capacity of the air to hold moisture, ( and so help clothes to dry,) but as soon as it cools or hits a cool surface, it will turn back to water. I had a tenant very recently where the problem was so bad that even her clothes were starting to go mouldy. The "problem with the property" disappeared the day she left! If the tenant is unwilling to deploy the dehumidifier when supplied, I really don't know what to suggest. They genuinely are an excellent and highly cost-effective means of combating the problem. It is also worth knowing that it takes more energy, and is therefore more expensive to heat humid air than less humid air. There is a technique of opening all the windows and effecting a total air change with outside air which has less moisture content in absolute terms, although its success relies on the inside temperature being warmer, thus allowing more moisture to be held in the atmosphere. Again, it requires the active participation of the occupant. If they are not willing, I really don't know what to suggest.