Mould spots on wall

bridgeman

Hi my house was built about 4 yrs ago and I notice in the main bedroom there is spots appearing on the walls , both internal and external walls . The spots are about 5-6 mm in diadeter looks like mould or mildew . Has anyone any answers to what could be causing this . Thanks .

pieface_ie

There is moisture getting in through the walls or coming from under the floor,if it's a upstairs bed room it will obviously be coming through the wall,I'm mo expert but it is a big job to fix the problem,the plaster board will need to be taking down to gain access to the area. Also make sure the room is well ventilated

slimjimmc

It could simply be poor ventilation.
Make sure the room vents are always left open, people often close them off during the winter and forget to reopen them. If you have an ensuite shower keep the door closed when showering and keep the ensuite ventilated. Moisture from the shower can travel into the bedroom.

bridgeman

Hi thanks for that it is a bungalow . Ther is an ensuite in the room there is an extractor fan in the ensuite should I fit a permanent vent in there or leave the extractor on for longer . I did have the vents closed for the winter . Should this wah off the walls or do I need to paint

slimjimmc

A permanent open vent would give good all day ventilation but might make the ensuite a bit chillier in winter (which I assume is the reason you closed the bedroom vents). Before you start bursting holes in the wall I'd try leaving the fan on a bit longer. Keeping the bedroom vents open would be best for there too.

The mould should wash off. You can buy mould cleaner (fungicide) in most DIY shops or use 50% diluted bleach in water if the surface is not sensitive to bleach.

jmbkay

Its caused by poor ventilation. You can get spray stuff in DIY shops, it covers the mould and then you paint over it.

PeteHeat

Hi,

The mould is usually caused by condensation, in this case the plaster boards may have been blobbed on to the block which would account for the spots.

As posted I expect the fan needs to run longer, also the vents in the bedrooms should not be closed they are supposed to be permanent vents to allow air changes.

.

LeotheLion

PeteHeat wrote: »

Hi,

The mould is usually caused by condensation, in this case the plaster boards may have been blobbed on to the block which would account for the spots.

As posted I expect the fan needs to run longer, also the vents in the bedrooms should not be closed they are supposed to be permanent vents to allow air changes.

.

and what if they were foil backed/insulated plasterboards that could not be the correct explaination.

PeteHeat

Hi,

O.P. has asked what could be causing the problem.

"in this case the plaster boards may have been blobbed"

If the boards were foil backed or insulated the cold could be transmitted by the fixings / nails or because the foil / insulation was damaged prior to or during installation.

Ventilation should be permanent in both the bedroom and the en suite regardless of the finish or methods or attachment used.

.

LeotheLion

Cold can be transmitted by plastic mushroom fixings?? :eek:
never heard of it,

I agree about the ventilation part and cowboys using damaged plasterboard

bridgeman

Hi thanks to all for the help . I guess it must be a ventilation problem and yes the vent was closed during the winter as there was a draught coming through it and making the room a bit chilly . There are no slabs on the wall as it is a solid block construction with plaster and a hardwall finish so that rules out the slab problems . Thanks again .

legs11

get a de humidifier and leave it firing away in the room for a bit