Condensation/damp

JuneBow

I have a rental property and there is mould on one of the bedroom walls upstairs. It is next to the ceiling.
The builder thinks it is condensation because it is black, but he says he is not sure so I need to get a specialist.
What sort of specialist would that be?
I have looked in Yellow Pages and I can see many entries for DPCs but not for this.
Is black mould always an indication of condensation owing to poor ventilation?

tony6403

Warm air rises and if contains moisture it is quite likely that the mould is caused by condensation.
I don't think that a specialist is required before you have checked out a few basics.
There are loads of posts on here about why excessive moisture gets into the home (e.g. drying washing on radiators , cooking , steam from bathroom) and you should think about these first.
Ventilation can be the answer but also have a look to see if there is water getting in from defective/missing roof tiles , guttering problems or the state of the joints in the brickwork.

smifffy1989

We are looking at the Nuaire Drimaster to fix an issue similar in our own house. Maybe worth a look!

adamslinger

As Tony has already mentioned, first rule out any structural problems, cracked water pipes or missing tiles on the roof.

Try to wipe off the mould with warm soapy water whilst it is still wet, drying out the mould will only cause the mould spores to spread to other areas of your home.

It is in your landlords best interest to solve the problem as ongoing maintenance and decorating costs will start to get expensive for them.

mcoyne1969

Most issues I look at as a surveyor are "household" issues such as people drying clothes inside, not using fans, not opening windows etc, try ventilation and / heat in the room. But as other posters say check externally to make sure roof / gutters are ok first

cyclonebri1

June, Tony is on the right track, it is highly likely to be a lifestyle issue.

IE, you put to much body moisture through breathing into the place.

You dry clothes, you cook steamy dishes etc etc.

Your heating and ventilation has to be able to cope with all this and still leave a nice warm and condensation free atmosphere. It costs unfortunately.

The only other issue is insulation, and I'm afraid in a rented property that is outside of your control,


"Is black mould always an indication of condensation owing to poor ventilation?"


yes, almost certainly

richardc1983

smifffy1989 wrote: »

We are looking at the Nuaire Drimaster to fix an issue similar in our own house. Maybe worth a look!

Ive had one installed for a month, best £300 ever spent, get the one with heat though! At the same time I changed the bathroom extractor fan to a Nu-Aire Cyfan, this has constant trickle extract if you need that option but the bathroom doesnt even steam up any more now we have both of these.

Heres my review from it on amazon...

I work in facilties management and HVAC for commercial buildings so I am used to dealing with large air handling units for office buildings and other complexes. I am aware therefore of how buildings have to provide fresh air for occupants. This is a simplified miniature version for the home. I bought the version with the heater option as it was cheaper to have it built in rather than buy it at a later stage. My main reason for purchase was for ventilation and fresh air because I live next the motorway so lots of noise and dust from traffic etc. I love fresh air also so my windows are constantly on the catch all the time but this means cold air just infiltrates the house but doesn't really ventilate. I don't have any damp issues other than the bathroom walls dripping with water after a shower. My house is a 2 bed small end terrace with 2 rooms down and 3 rooms up double glazing no trickle vents, cavity wall insulation and above the recommended loft insulation.

I had issues with cooking smells lingering and getting upstairs along with bathroom smells coming downstairs and the usual stale bedrooms on a morning, despite windows being left on the catch 24/7 it made no difference. The fan was installed by an electrician with the vent put into my landing ceiling. It was recommended for the size of my house that speed setting 2/3 was used but I couldn't feel much air flow from the vent. As I wanted to actually feel fresh air coming into the house the same way an open window I put it onto speed setting 4. I closed all the windows so the house is only relying on the Drimaster fan to ventilate and within half an hour the landing felt and smelt fresher with clean filtered cooler air coming in. My lodgers were cooking burgers and frying them in the pan that evening (I hate frying smells) and usually you can still smell this through the house the next morning especially the kitchen. Now the next morning there were no cooking smells at all, nothing unpleasant just fresh and aired. The house even felt warmer. Our kitchen is also feeling warmer and this is the coldest room in the house as there are cold draughts coming under the cabinets and around appliances.

What the fan does is filter air from the loft & pump it into the house from a central point (landing) which then pressurises the house. This is the same as what they do in operating theatres to ensure there is no dirty air penetrating into the theatre environment. Imagine a balloon with holes in it and your trying to keep it blown up. The balloon is the structure of the house and the holes represent the air gaps within the house such as cracks around doors under floors and air bricks that sort of thing. Normally outside air will penetrate these gaps which results in a cold house and that's how your house normally ventilates but inefficiently so. The fan is technically blowing the house up keeping a gentle pressure that is higher than outside so any stale damp air is pushed out through the gaps inside-outside. This means that the cold air that was coming in round cupboards and skirting boards in the kitchen are kept at bay. Any smells and humidity are constantly diluted down with the filtered, clean, fresh & dry air.

I'm amazed at how good the fan is at circulating the air. This is not a propeller fan like you would have on your desk (which would do nothing) it is a Centrifugal fan which are used to push air and create pressure in a space. If its 12C outside the temperature of my loft is 16C, I fitted a digital thermometer in the loft and one outside to compare... so instead of 12C dirty polluted air coming in through the windows I now have 16C air blowing into the house. Should the loft drop below 10c the small 500w heater will kick in and pulse on and off to increase the air temp upto 8C this is just for comfort of the occupants so you dont feel icy cold air circulating on the landing and its there as an option should I decide to fit it on a timer so that the heater part only runs on a morning when people are getting ready or on an evening. We had a cold night last week where it was 4C outside and the loft was at 8c so the heater kicked in and the air blowing out was at 16C on the landing.

Yes it makes your landing a little cooler but if you want a fresh and dry home then there has to be compromise and nothing is free but this is the best and most efficient way of achieving it without expensive dehumidifiers. Even if your heating is on a bit longer this still no where near like the running costs of a dehumidifier which don't really help and cost a lot to run. Nothing can beat fresh filtered air and plus the air flow from it is warmer than it would be opening a window due to the loft being 4/5c above the outdoor temperature. You might as well reuse that heat that has escaped into the loft as even if you have the best possible insulation heat will still escape.

Hope this review helps people, don't hesitate in getting one I wish I had got one sooner. The house is less draughty especially on the landing & stairs where you could feel the cold air from the windows on the catches just sinking down the stairs. Anyone that has had poor luck with these you either need to adjust the fan speed higher or lower. If its too draughty turn the fan down or turn up if you are not getting the results you were expecting. Keep all windows closed as air will take the easiest route out of the house and that will be the windows. Leave internal doors ajar.

Any questions please ask

cyclonebri1

richardc1983 wrote: »

Any questions please ask

1 question;


Given the depth of reply to a specific product, are you in anyway attached to this company, ie, is your reply SPAM?

richardc1983

cyclonebri1 wrote: »

1 question;


Given the depth of reply to a specific product, are you in anyway attached to this company, ie, is your reply SPAM?

No not at all I literally copied and pasted my review from amazons having already bought one. It's an in depth reply as I am very knowleagble on ventilation. I think with the number of post counts I have I do not spam. I answer a lot of posts on heating. Is someone not allowed to put a detailed reply these day?

poppellerant

A very good, realistic, opinion of the system here: http://www.doyourdream.co.uk/2013/01/installing-a-drimaster-heat-piv-system/

I'm certainly looking into these now.

caz_who_loves_a_bargain

We have a similar problem in our house with condensation and i appreciate the information and links to the nuaire drimaster . The only concern i have is that our loft and next doors loft are 'open'. We have a wall between the 2 loft spaces with a doorway sized opening between and because the roof is so high the dividing wall only reaches up to about 7-8 feet so there's a large opening over the top as well. Would this make any difference,and would we need the neighbours permission to install one ?