Modern house - orange/brown mould

Postby Claremb » Fri Mar 27, 2009 6:51 pm

I apologise as this has undoubtedly already been answered but I have spent alot of time searching and not found it yet.

Our house is an end terrace and was built in 2004. We have all our trickle vents open unless it is very windy out in which case we may close them in bedrooms on the appropriate side of the house.

We have orange/brown mould rising 2/3 up the walls in 3 corners in the living room, corner of cloakroom. There is no furniture against the walls in these areas.

We have orange/brown mould coming down/across the walls in 1 corner of bathroom and 1 corner of son's bedroom and a 40cm line extending down wall by approx 2cm and onto ceilng by approx 2cm in daughter's bedroom.

There is no evidence of condensation on any of the windows downstairs but occasionally some in the morning upstairs and occasionally some on the letterbox.

Any help with solutions would be very much appreciated. Thank you in advance for your time.
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Simply Build It

Postby stoneyboy » Sat Mar 28, 2009 7:16 pm

No I don't think this problem has been raised in the recent past.
Do you dry clothes in the house, have you got a kitchen extractor, how about a tumble drier not ducted to outside.
You do have a serious damp problem - how often do you open the windows, do you open the windows when sleeping in the bedroom.
We need more information to be able to help you.
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Postby Claremb » Sun Mar 29, 2009 2:33 pm

We do dry washing inside - up to 3 loads a week during bad weather - but I always hang it outside if possible. We don't have a tumble drier.

There is an extractor in the kitchen and we often open the window as well. I can't see any mould in the kitchen.

We use on of the french doors in the lounge/diner as the main entrance/exit of the house so it is frequently open for short periods of time (long enough to get the children in and take their shoes off before I come in). The front windows in the lounge aren't open very often but there are no traces of mould on or around the window frames. There is a speckling of dark brown mould on either side of the french doors rising approx 5cm and I have noticed more of the orangey/brown mould behind furniture by that wall. Both items of pine furniture are a minimum of 15mm away from any wall.

The window in the cloakroom is usually shut during winter months and then left locked slightly open during the summer months. The trickle vent is always open BUT I've walked around the outside of the house looking for any indicators and noticed that the trickle vent is completely blocked with the paint and sand mix that the house is painted with. The way it has been put in means there is no way I can remove it and replace it.

That's downstairs covered. Upstairs we have 3 bedrooms. During the day, the windows are often opened regardless of time of year (I'm a bit of a fresh air freak!). The master has an ensuite which doesn't have a window and relies on an extractor fan which the developers insisted is adequate. We have always had a low level problem with black mould in the ensuite. In the bedroom itself, the window is occassionally open and frequently secured slightly open overnight on milder nights. On warmer nights, the window is usually left open.

In the children's bedrooms, the windows are rarely open overnight during mild weather but usually open until 11pm and then secured slightly open for the remainder during warm nights. There are a few black mould spots on the sealant in both these rooms.

In the main bathroom there is an extractor fan and the window is usually open at some point during the day, maybe secured on latch if the weather is bad.

All the orangey brown mould spots are on external walls, there is nothing on internal walls.

The trickle vents are rarely ever closed. Even when it gets cold - I tend to forget about them - but if it's very windy, I may close them upstairs on 1 side of the house. There isn't any mouldy or musty smell.

On the exterior of the house I've noticed an obvious patch of black mould between the trickle vents of the master bedroom and an even darker patch next to 1 trickle vent of my daughter's room and the blocked trickle vent which is fully enclosed by the structure of the house with only the one blocked face visible. as mentioned above.

I hope that is enough detail but obviously ask away!

What is the difference between black, dark brown and orangey brown mould? I've found lots of info about black mould but not about brown etc.

Thank you so much for your help.
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Postby stoneyboy » Tue Mar 31, 2009 5:51 pm

Well done with the detailed explanation.
With your house being only 6 years old I would not expect structural defects to be causing the mould growth.
Black/brown mould - I would suspect you have trees nearby which are giving off spores.
Clean off the mould with a bleach solution.
Buy a humidity meter ( a cheap gardening one will do) and see what readings you get in different rooms.
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Postby Claremb » Wed Apr 01, 2009 10:41 am

Thanks for the advice Stoneboy. I'll go and get a humidity meter, clean all the walls and redecorate with some good quality paint and we'll see what happens.

Thanks again
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Postby rigga » Thu Apr 02, 2009 8:04 pm

It seems to me that the insulation has been cut short into the corners. If your house was built in 2004 then the walls should have sufficient insulation to stop any cold spots, just about the time they changed from a 50 mm cavity to a 75 mm one but never the less the insulation if cut short into the cavity would cause cold spots. This is where mould if spores are present will grow. Warm room, cold wall, poor air circulation. Air does not move into the corners. My advice would not be to use a bleach solution this would crystallise on any finished plaster and the next time the wall is wet you will end up with bleach running down the wall. Not to mention the damage to fitting and surroundings. I would recommend Milton sterilising solution mixed to the manufacturers recommendations try to avoid wiping the mould around if you have to wipe or brush into the mould. This will stop the spores from spreading. As for the insulation. You could try removing a brick from where the damp is on the exterior to check this, if this is evident remove a brick at the top of the wall section and insert cavity insulation beads; this will fill up the void where the insulation is missing.
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