Why do houses in the uk mould so easily?

[december2020]

My understanding is the main causes for mould is condensation, humidity and rising damp.

I live on the UK but I'm originally from Scandinavia and mould doesn't seem to be a problem like it is in the UK, yet there is humidity from steamy showers and cooking in the kitchen as well as prime condensation conditions like warm inside and cold/minus temperatures outside - but the windows never have condensation and it's rarely a problem.

Why is this? Maybe a dumb question on my part! Im really curious (also in case there is anything I could be doing to future proof getting any mould).

All of the above

My very old house in Sweden is properly ventilated. I'm not talking open windows and a light activated extractor in the bathroom. It's a full on ventilation system that runs constantly and has ventilation ducts in every room. Originally it was powered by the chimney which sucked air through the ducts. Now it's electrical as the fireplace is gone. We had an awful problem with damp when it broke down.

Agree, but this is the primary answer to the question 'why do houses in the UK get mouldy'.

@Chewbecca Yes true.
A ventilation system sounds a good idea but what about costs, does it have an integrated dehumidifier?

No idea. It's constantly sucking fresh air through the house. There are inlets and outlets in every room and all the old damp air disappears up the chimney. The machinery is like a cap on top of the chimney.

There are extractor fans that also recover heat from the air, and control humidity. They can be room focussed if having a centralised system seems overwhelming. Opening a window will also exchange wet air for drier, usually even when it's raining.

Q: Why do houses in the uk mould so easily?

A: The "maritime, moist and temperate" climate in combination with a poorly constructed housing stock (in the main).

Much of the housing stock is old, or very old. Originally, these houses were highly ventilated via natural airflow, but this ventilation was gradually interfered with as people moved away from having open fires to central heating systems, from looser fitting timber windows and doors to tightly sealed uPVC units, and other measures, that steadily reduced the exchange of air from inside to out. These changes were compounded by reducing the breathability (ability to transport moisture outwards) via measures such as vinyl paints on walls inside and many masonry paints on the outside, plus cement renders and pointing on the outside. And for these poorly constructed homes, you get to pay some of the highest prices in the world 😉

The age and construction?

I've never had a house or flat go mouldy though and I've bought homes constructed in the 19th to 21st Centuries.

when I rented a flat in germany attached was an 'airing table'. basically instruction how to air effectively and how long.

plus clothes were not to be dried inside the flat. there was a laundry & drying room in the cellar.

(was an old house, built in 1900, similar to many many british houses)

Old, poorly maintained housing stock.
Poor ventillation.
Poor insulation.
A damp Atlantic climate.

In terms of housing stock age, there's a period in the 1920s to early-1950s when housing was generally well built, well proportioned, and airy. These are less prone to damp - although they can have issues with poor maintenance or botched insulation (a lot of cavity wall insulation refits were poorly done).

Many Victorian -1920 houses were less well built and/or have suffered from poor maintenance and are prone to damp.

Mass build of the 1960s-1990s can be shocking for ventillation, insulation and build quality.

Post-1990s developments have theirown issues, but are generally better as buildings standards have improved. Although there is an ongoing issue with adequacy of ventillation in the pursuit of nominal energy ratings.

The addiction to property value (and heritage/tradition) in the UK has meant that there's a strong reluctance to demolish poor quality housing stock and replace it with more efficient, modern homes.

Yep, we moved into damp flat where radiators were literally rusting and mould around window seals. But we're not skimming on heating and opening windows regularly, so it s no longer damp. There are a lot of brits that just don't heat their houses/bathrooms. Simple as that.