How to tackle mildew?!!!

Have you tried using a dehumidifier to prevent the damp in the first place?

You first need to find out what is causing the condensation.

The causes are going to be:
1) EXTERNAL, either thin external walls without insulation, probably east or north facing this means that the walls get very cold inside and any internal warm air hitting the walls causes condensation or solid walls facing probably facing west that get the brunt of rain, so that the walls are getting soaking wet and the condensation is arising from water evaporating from wet walls. The answer to both is likely to be wall insulation.

As it is a block of flats it is unlikely you will be able to install external insulation so internal insulation is the solution. You will need to get a builder to line your walls with insulated plasterboard or frame them up, fix slabs of insulation the wall and then plasterboard over them. If you are on a benefit of any kind; Pension Credit or a disability benefit or if you income is just above that level it is possible you can get this done through one of the Energy Company/Government schemes.

However if the problem is water penetration, all other flat owners on the same face of the building as you will have the same problem and you should contact the management of your flats about the wall being treated from outside to stop rain penetration.

2) INTERNAL. This is probably the more likely cause as you say your double glazing is fogging up. It is caused by either excessive generation of water vapour in the house; drying washing indoors, unvented tumble dryers, using stand alone Calor gas or similar heaters that generate a lot of water when in use or inadequate ventilation. Do your double glazed windows have trickle vents along the top of the frame. Are these closed or blocked? While it is good from the heat conservation point of view to reduce the number of air changes each hour, take this too far and you get condensation. Buildings built to be highly energy efficient also have forced ventilation and heat exchangers to keep condensation down. You will need to find ways to ventilate the flat, extractor fans of some kind in the kitchen and bathroom are the best solution, using them and keeping the doors to these rooms shut when in use.

Sorry for such a long post but with a condensation problem as bad as yours sounds. The only solution is to find the cause of the condensation and remedy that. Apart from anything else the conditions you seem to be living in now can be very bad for your respiratory health.

Wot she ^ sed! (sic)

Flickety respect! But - Grummy I do hope it helps. It sounds awful.

Agree with Flickety.
We had a similar problem (though completely different situation, old damp rural house). Last owner had painted over with plastic type product.
Needs to be stripped back and dried out, then either insulated as F. says, or treated with an antimould product and replastered with a breathable plaster.

Your local environmental health team will be able to offer some advice, and may have grants if you need work done

We have a lot of mould on our walls. It`s always on outside walls, where there`s furniture placed, so can`t be seen till furniture is moved. Have tried many products for mildew, no success. It`s an old end terraced house.

Try waterproofing the outside of the wall and move the furniture out from the wall so that there is more air movement behind it. Best of all, fit or get fitted, exterior wall insulation on that wall. That will sort the problem.

What do we use for water proofing? Sorry, I`m a bit thick about these things. The furniture isn`t actually touching the walls, but not really room to move it further out, only small rooms.

Most DIY stores will sell suitable water proofing liquid and should be able to advise. Your really need to get advice from a builder. If you are on any benefit you may be able to get a grant to have insulating cladding put on the wall.

Thompson do a clear liquid which penetrates the brick etc and waterproofs it all. They also do a product for painting walls on the inside which prevents marks showing through new paint. We had a house where a gutter down pipe had leaked - problem pipe was fixed but you could still see the mark the damp had made on the inside - after painting with the barrier stuff it did not show through the new paint I put on. DIY stores also make their own stuff but read any of the tins carefully to see it appears to do the job you need doing.
Lakeland do a spray which is great for any mould starting up in the bathroom etc - as soon as the first sign appears out comes the bottle!

I've got an old house circa 1850amd I have just had the outside silicone sprayed to make it waterproof. I do however still have mildew condensation on my inside plastered windowsills where the cold outside stone clashes with the warmth. Thinking of having it lined with plastic wood!

I was warned against that with my similarity aged sandstone house?

My son -I-L is in the process of removing the render from his old brick farmhouse as it is clear that the house needs to breathe in order not to encourage damp, mildew and death watch beetle (who love a damp place to reproduce in!). He is going to lime render it. Silicone sprays just make things worse I am afraid. He took advice from a friend who renovates old houses and knows about this stuff. We also received the same advice when we moved into our old stone cottage.

I would be worried that waterproofing the stone would be more likely to seal damp in and prevent the stone from breathing.

On a Geological walk in Sheffield my geology guru was saying that some older houses in Sheffield, built for the accommodating the labouring classes as quickly and cheaply as possible, have some very poor quality sandstone on them. We saw some of this where it outcrops on the west of the city.

In recent years people have attempted to clean the years of heavy industrial grime off the stone to clean it up. Cleaning appears to have made the surface deteriorate even faster. All the grime was probably holding it together. One needs to be very wary.

Waterproofing stone will not seal the damp in. Any damp will gradually dry out through the inside walls. What the damp proofing does is stop any further damp entering the stone.

The ideal solution to the problem would be to fit external insulation to the wall, which will stop the wall getting both wet and cold and will reduce the occupant's heating bills significantly. There are grants, but if you do not qualify I would not think getting one wall of a terrace house insulated would not be outrageously expensive. But I accept one person's definition of outrageously expensive is not another's.

In the past in the area where I live houses with a wall facing into the weather often have tile or wood cladding on the weather wall to protect it from the worst of the rain.

I have an 1891 brick built end of terrace. Windows are double glazed and the loft well insulated, but there's no cavity to insulate. I can't help thinking that external insulation would spoil the character of the house, so what more could I do?

Good advice from flicketyb. The cause needs to be properly identified - dealing with the mildew itself - its just going to re grow. Its a microscopic plant that needs a supply of water from condensation.
Is it rented grummy? If so public or private?

anno I have an 1860 cottage with a single skin of bricks, and had the external damp-proof ceramic bricks fitted 7 years ago. I never notice them as they blend in with the original bricks, and they've done the trick in tackling mildew and damp. Much less intrusive than internal damp-proofing and re-plastering a metre up from the floor.

penetrating rather than rising damp maybe when
anno the only alternative is dry lining but that reduces the size of the rooms, but worked OK on a spacious London terraced house I know of.

Both, Jess. A cottage built on minimal foundations. Pointing sorted the penetrating damp out, and after the front wall showed the damp had dried out, I had it sprayed with a damp protector. It was interesting to see earth when the old fireplace was removed!

Annodomini You can also fit internal solid wall insulation. A friend did that in a house with moulded cornices around the wall/ceiling joins. they took these off and were able to get replacement lengths of cornice made to the same pattern. When you are in the room it looks just as it ever did

Internal insulation is only about 3 inches thick and in a terraced house only one wall in each room will need to be done, so I do not think that the reduction in one dimension of the room will be significant.

It's an end terrace, so there would be three walls in each room! I will make inquiries but I'm not sure I can stand the upheaval.

Hi all, very helpful and sensible advice! However the flat is rented, all the flats in the block have the same problem, I am on a bread and butter budget and the landlord would not be interested in doing anything about fixing the mildew problem internally. So on I will have to go until the lease and I shall hopefully find a drier place to live!