What Humidity level in my house is right in the UK

dominoman

Since we moved in around a year ago we have always had high humidity.

The problem actually decreased last winter but now humidity is really high again. I installed a couple of remote meters under the floor and it is regularly above 75%. Even in the downstairs hall it is now 70%.

The house is an Edwardian house and well ventilated. Really not sure what to do next?

DRP

Do you have damp problems? mould on walls/ceilings? condensation in the winter? does it smell? etc

If not, does the high humidity matter too much? (especially if you are measuring under the floor)

We have a problem Edwardian terraced house where previous owners had blocked underfloor ventilation t front and back and filled the subfloor void with mud and rubble. There was also a broken gutter for years in one corner. All this has led to a smelly, damp house with high humidity.

We increased the airbricks, cleared out the sub-floor, fixed gutter (finished the work about 5 months ago) - the smell has gone, but the downstairs hall is still humid (60-90%) compared to the rest of the house (45-60%).

A few things i would check:

1. Is it wet under the floorboards? soil or cement at ground level? any wet or rotten wood?
2. How many air bricks and are they blocked - you need them back and front to create through flow.
3. Check for leaks in plumbing, crappy gutters etc have a look in the loft too.
4. Double glazed? Open the windows every day for ten minutes.

dominoman

Thanks DRP for the advice and the empathy! Nice to know I'm not alone.

Last winter we had a lot of condensation, but that has now gone, and I think was just because we had no working central heating for most of winter.

The problem now is mainly on the ground floor. There aren't any visible problems of mould, but we do have woodworm and I don't know if it is still active. I know that higher humidity helps woodworm spread so that is one reason for tackling it.

The other problem is a damp cellar, with water gathering on the ground in one corner (not a pool, but wet to the touch).

Under the floor is dirt, with years and years of old building rubble and discarded paper and bits and pieces. It's a mess and I am sure all this is helping retain moisture but it is hard to get to without lifting floorboards. It isn't impeding the air flow so I've left it.

paddyrg

Condensation is actually a sign of lower humidity - the water has condensed out of the air! But 40-60% is 'normal'.

Even on a wet day, the air outside is usually a lot drier than indoors (and warmer air holds more moisture), so keeping windows open can be a big help

stator

Get a dehumidifier in. If it produces 1-2L of water per day you know you've got a leak somewhere

50% is okay. 60% is a bit high, 70% is too high in my opinion. But I've found humidity meters not very accurate, they rarely agree with each other, but mine are all cheap. Maybe yours is ok.

dominoman

stator wrote: »

Get a dehumidifier in. If it produces 1-2L of water per day you know you've got a leak somewhere

50% is okay. 60% is a bit high, 70% is too high in my opinion. But I've found humidity meters not very accurate, they rarely agree with each other, but mine are all cheap. Maybe yours is ok.

I have a dehumidifier in my bedroom, which is actually one of the least humid rooms. It easily fills its full 5 litre tank in a day! I now set it to near minumum so it keeps humidity around 65-70 so I don't have to empty it so often.

I suspect there is a leak somewhere...

PasturesNew

I've never heard of anybody being concerned by humidity, or discussing humidity in their homes.

What is the actual problem you are experiencing that makes you wish to measure/compare it?

stator

dominoman wrote: »

I have a dehumidifier in my bedroom, which is actually one of the least humid rooms. It easily fills its full 5 litre tank in a day! I now set it to near minumum so it keeps humidity around 65-70 so I don't have to empty it so often.

I suspect there is a leak somewhere...

:eek: Is your name spongebob squarepants?
5 litres per day is huge. Most dehumidifiers only have a 2l tank and would struggle to fill it in one day unless left in a suana.

SG27

PasturesNew wrote: »

I've never heard of anybody being concerned by humidity, or discussing humidity in their homes.

What is the actual problem you are experiencing that makes you wish to measure/compare it?

It causes damp and eventually mould growth.