Mould caused by double glazing??

[TiredMum30]

Hi, posting here for traffic.

We have mould in our rented property, had the landlord out before and brickwork needed repointing, a guy came out and did the bare minimum, even I could have done a better and more thorough job then he did, so there's no surprise that the mould still keeps growing.
it's in 3 rooms, the walls and furniture it's growing on are along outside walls. The humidity in the house is ridiculous, so we always have to keep windows open during baths/showers/cooking, and i generally keep them open a little during the day anyway to try and reduce the mould growth.
Anyway the landlord sent another guy around today, this guy said its because this house wasn't built for double glazing! Erm is this correct? Is that what's causing the issue?
There's a tiny plastic vent above the oven in the kitchen and no vent at all in the bathroom upstairs, I feel like these may also be adding to the issue, aswel as the gaps in-between the brickwork outside 🙈
Just checking because I'm going to email the landlord again, because both me and my son have had persistent chest infections earlier this which took multiple courses of antibiotics to clear, so I don't want to get to next winter without the mould being sorted properly.

Ventilation is key. There should be external extractors in both bathroom & kitchen, but even with this, windows need to be opened after showering/cooking. I am a landlord with a property owned for over 20 years. About 10 years ago I had tenants that were new and very quickly were overrun with mould, never happened before & has never happened since they moved on. So it is often very much a lifestyle thing. Lots of cooking, drying washing indoors & lack of opening windows at peak steam times will result in mould.

I would always expect to open the window or use an extractor fan when using the bathroom. The fact you think this is unusual suggests to me you aren’t really managing the property the right way to avoid mould.

Your landlord is never going to be able to prevent mould for you if you don’t open windows after showering.

Kitchens and bathrooms should really have extractor fans to help manage the humidity. If the property doesn't have them as standard, could you try running a dehumidifier?

EDIT: but having windows open during baths, showers and cooking is fairly standard.

OP, it sounds as if you are doing the right thing in keeping the windows open when showering / cooking and in having them open a bit during the day. Please do keep on doing that.

If that isn't shifting the problem there is every chance that the house needs some attention, not your behaviour. Things that might be needed:

Trickle vents (which are more common in double glazed windows than old single glazed, despite what your builder is saying!), actual working extractor fans in kitchen and bathrooms, better undercuts in doors to allow air to circulate throughout house. It could certainly be a problem with pointing and damp penetration into the home. The fact that it is along all the outside walls also suggests you have insufficient insulation.

Are you able to run the heating much at all? This would do two things:

1. warm up the fabric of the outside walls reducing the condensation on them,
2. hold more water vapour in the air, which means that if you ventilate effectively then you will get more humidity out of the home.

I don’t think it’s a ventilation thing apart from the bathroom should have a decent extractor fan and ideally the kitchen but my house has neither and no mould apart from where the roof has been leaking. That small area has gone black really quick and it’s only just been fixed as we needed a dry day! So I think it’ll be water ingress unless you’re showering 3 or 4 times a day, drying washing inside and boiling lots of food.

Problem is, condensation is one of those things where there is a lot of variation between homes, so what causes a problem for OP might not for the rest of us. Some factors that can vary which aren't ventilation:

• number of people in home, plus how many hours they're in the house
• actual size of rooms (small rooms with lots of people fill up with moisture even if they aren't washing / cooking)
• heat loss through the walls / windows (cold surfaces get condensation quicker)
• how much the home is heated

I work in this area and unless there is significant water ingress mould is normally due to the use of the property. It is unlikely to be anything to do with some shoddy repointing. It can be due to inadequate insulation or cold spots where there are gaps in the insulation but most often it is down to inadequate ventilation.

You should ask your landlord to install extractor fans in the bathroom and kitchen and you should use them.

You should also open the windows and air the house daily and have your trickle vents open at all times.

At this time of year wash your walls down with Milton or dilute bleach and get your windows open all day. The better weather will help get everything dry.

In winter it is more difficult especially if you are trying to reduce your heating bills as you still need to open windows and you also need to keep the house warm. You may find a dehumidifier and a window vac help. If you regularly dry clothes indoors then you really need a dehumidifier.

I’ve lived in two houses prone to mould and I’d say it is mostly down to ventilation but also direction your house is facing. My first house, a Victorian terrace had shocking mould on any cold outside surface. The only thing that worked was opening windows for at least a couple of hours a day and wiping with dettox mould remover the minute any appeared. I was obsessive about never having anything against an outside wall as that is lethal in an mould prone room. Even now my adult children remember the fuss I would make about it. My second house, a 1930s semi was a lot better but I noticed the north facing rooms were very prone to mould and I carried on the same habits to control it. Our small bedroom was so bad, I lined it with polystyrene on a roll which really helped although the kids loved poking holes in it. We got extra lagging in the loft two years ago and noticed, the following winter, mould appearing on the hall ceiling next to the north facing wall so I just stepped up the window opening in the hall. I hate waking up to winter condensation on windows with a passion, but I have found windows only need to be open a tiny amount during the night to cut it down significantly, especially when drying clothes indoors. Safety aspects of leaving windows open at night though do impede this.
I was reading modern double glazing have ventilation vents in them. Does anyone have experience of these….. Do they make a diffference?

I leave the trickle vents open in bathroom, kitchen and living room all the time, but I keep the windows closed when showering, and just open the bathroom window a bit when I leave the bathroom afterwards. And I dry washing indoors a lot of the time but don't get mould, or condensation save for when I shower.

I do have great double glazing though, maybe that helps, and cavity wall insulation.

I'm sorry, I don't think I worded it properly. I don't think it's unusual to open the windows during cooking/showering etc I just meant that we do have them open. we do ventilate every day regardless if we're cooking/showering or not.

The mould was also an issue for the previous tenants, we was promised the issue would be fixed before we moved in but unfortunately they just popped a bit of paint on one area and that was it. When we moved in the walls was covered in mould underneath the wallpaper, we stripped it all and then either painted or papered. I've had to strip my daughters wall at the beginning of this year due to mould growing underneath it, her window is open slightly all year round, front bedroom windows are open during the day but closed on a night due to noise from the street/road but my son will often just leave his window open slightly because the noise doesnt bother him as much. We also run a large dehumidifier on the landing all day and night.

I'll also say that the issues are upstairs, they didn't do any repointing on the upper part of the house, just lower. There's actually a brick missing in one spot where the condestation builds up and the mould is growing, the paper has started peeling off in this spot.

In regard to the comment about it depending on which side of the house it is, we're semi detached the mould is growing on the side of the house, there's a passage way between our house and the neighbour, It's often dark and wet down there and gets no sun, so that could be an issue. If we look on the wall outside you can see the bricks are damp in certain areas and not others.

I don't dry washing in the home, we're out for the majority of the day with work/school so there's not constant showers or pans being boiled all day. There is definitely some water getting in because I have a built in cupboard also along that wall where water drips in when it's raining and it's caused the plaster to crumble.

I think I've covered everyone's comments so far.

There's also no trickle vents on the windows, they're quite old windows, they gather alot of condensation during winter so I use a window vac in a morning.

We've literally tried everything we can to reduce the humidity but it doesn't seem to make any difference.
I'm not sure if the house is insulated, I know the loft is but it's more or less just been thrown about and stacked really high in some areas and barely any in other areas. I've no idea if having that evened out would?
There's obviously cold spots along that wall because the areas where having issues with are alot colder then other areas on the same wall.

There's no actual extractor fans in the house at all. Just those plastic ones.
And there's also no air bricks in the house, besides a couple on the kitchen extention. I thought this was strange because our previous homes have all had them all around the bottom of the houses.

I do think there's a tendency to blame residents for mould. I've only ever stayed in one property that got mould and there was some sort of problem with the external cladding of the building, luckily that was just a rental.

Also my sons bedroom has a medium sized dehumidifier running too.

Always leave ventilation in kitchens and bathrooms. If you don’t, mould will come along.

The thing about it being the wrong kind of house for double glazing sound like bollocks.

The newer stuff with trickle vents is better, but it sounds like there is serious damp coming from somewhere too. Can you get your own expert in to look at the place? Or maybe the council can help.

I think so too, we've never had mould issues in previous properties we've lived in and we've tried everything we can to prevent the high humidity in this one, I'm not sure if there's anything else we can do ourselves. And the fact that the previous tenants also had mould and damp problems shows its not just us and our lifestyle

Please read my follow up comments, I stated that I worded it wrong. We do ventilate.

I've spoken with council and they said they can contact enviromental health, but i'm worried if we do that the landlord will look at evicting us. Houses in this area don't come up often, but if it's not solved by next winter we'll have to look at moving.

We do have a leak in the dining room ceiling which we think is from the pipes underneath our daughters floor, that was another reason why we had them round today. I don't think that would cause issues with damp and mould on the walls though, unless there's maybe a leak somewhere else? The leaky room hasn't had any mould since they repointed some of the brickwork outside.

When I had double glazing installed the company warned me that I will need to ventilate by opening them/using vents. The old windows were single glazed, wooden frames and you could feel the air flow if you sat near them. So there is truth in what he says, one of the reasons that early 1900 terraces didn’t get mould was because of the ventilation from chimneys, airbricks and single glazed windows. A lot now get it because modernisation prevents airflow.

Agree. These threads always annoy me. I grew up in a large old house now live in a modern small house. So both ends of the spectrum. We never bother to open windows when cooking or showering unless the food stinks. We dry clothes indoors and neither of these houses have had damp apart from when our chimney was leaking in the old house.

But I’ve lived in 5 rentals in between those houses and 4 had mould in which landlords always insisted it was us drying clothes inside or not leaving the window open 24/7. We would always change behaviour to try and sort the problem and It never worked. It was always landlords ignoring structural issues like missing roof tiles, leaking pipes or paying for shoddy repairs.

op if water is coming in through the walls there isn’t really anything you can do. You can only move out. You really shouldn’t be paying to redecorate that’s a landlords remit!

Not cheap to buy but I got an electric dehumidifier for nothing on freegle and have never looked back. I'd never be without one. It's on from October to April during the coldest weather and pulls a ridiculous amount of moisture from the air, no mould anywhere since.

We have a large one that we keep on day and night on the landing upstairs and our son also has a medium sized one in his bedroom but I'm thinking I may buy another large one and have it in on in the kitchen. The one on the landing collects alot of water and is great.

We are in a house that’s been in the family since it was built. It never ever ever has a mould issue untill it had cavity wall, central heating and double glazing installed, even after the chimney was blocked was fine, double glazing was fine, till central heating.

So I do think it’s to do with houses being made more air tight and heated so well as well.

But also the out houses get mould and they are airy as fuck 😅

Surely if your son keeps his window open slightly, you are trying to dehumidify the universe and giving the machine far too much to do?

Keep furniture 2” off the external walls if you can. Rooms need to breathe.

Local council should have on line info about avoiding condensation mould. If you ask council to visit & advise, they will talk to you as you’re the ones who’ve engaged them.

Your LL won’t get to know unless you tell him? It would be up to you/him to act on the council report.

Give Shelter a ring. They have lots of helpful advice too about mould & damp issues. Check out their website.
You seem to be doing everything you can to mitigate the issue. I hope it can be resolved.

This is a good link:

https://www.envirovent.com/help-and-advice/why-ventilate/?utm_source=google&utm_medium=cpc&utm_campaign=luke_robinson&utm_term=home%20ventilation%20system&utm_content=596266399849&gad_source=1&gbraid=0AAAAAD8JkXAqBhnztoQO0N6eBZrJoimc2&gclid=EAIaIQobChMIqaDioMTghQMVxZFQBh3FfghcEAAYASAAEgKgnfD_BwE