Mould in bedroom !

[Mike]

Hi all

We had an extension build three years ago and now there are signs of what I guess is mold.

What causes this and what is the best way of getting rid of it ?

Many thanks for your time and regards

Mike

A leak or condensation. If thats an outside wall or chimney breast it could indicate you need a bit of repointing, maybe a leaking drain or guttering on that wall.

[Raistlin]

There's damp getting in there somewhere, how it's getting in will depend what's above that wall/ceiling joint.

What sort of warranty did you get with the extension?

[Halcyon]

As xocemp has said, it could be a leak, maybe a gutter on the roof that is leaking and water is falling up against the wall and seeping in.

If thats a joining wall from the existing house to the extension, it may also be worth have the flashing checked, flashing is what was lead and still could be lead on your property.
Get a few builders in 3 or more to give it the once over and give you a price. And see if they all come up with the same problem area.

[Rob]

Black mould like that is normally condensation. You do need to work out where the moisture is coming from.

Is that ceiling against an external wall and to a roof? If so there could well be a lack of insulation pushed against the joint creating a "cold bridge". There may be physical building work needed to address it, and try to fix the joint. You also need to look at the amount of moisture you are trapping inside the home (simply breathing in a bedroom overnight creates a significant amount that's going to go somewhere), as well as looking at ventilation and temperature.

I'll attach an info leaflet on condensation I recently prepared, in a moment or two.

I have the same type of problem, the mold is in 4 upstairs rooms on the ceiling above the windows. I use a cloth dampened with diluted bleach, it seems to work for a week or more before it comes back.

[mr_bo]

Use a dehumidifier as a temporary solution to keep it at bay until the root of the problem is solved.

[Mick Fisher]

Get rid of condensation at the point of origin before it condenses out on the first cold surface it encounters. Use a cooker hood vented to outside and an extractor fan for the bathroom and you have accounted for the vast majority of it.

Also check in your loft in case, for some reason, your Central heating system has started 'pumping over'.
If you have an electric immersion heater check that it is not over heating thus causing the water in it's header tank to get hot or even boil. If you cannot stand to hold your hand under the hot tap, as a rule of thumb, it is too hot, at or over 60C unless you have set it this hot on purpose.
While you are up there it never hurts to check the status of any warning pipes. Some are only push fit systems and I have seen some drip a little water inside from a loose joint before expelling the majority outside.

Otherwise

Blocked/leaking guttering and/or blocked/leaking downpipes need checking as does any problems with slipped or broken tiles/slates.

[Mike]

Originally Posted by xocemp

If thats a joining wall from the existing house to the extension, it may also be worth have the flashing checked, flashing is what was lead and still could be lead on your property.

Thanks for all the informative replies really apprecaited. I attached another picture. The wall on the right is the extension coming out from the house which has areas of mold. The picture also shows parallel wall (left) which has a area of mold just starting to appear which is where the extension joins the house.

About 2 years ago we had the roof insolated with 10 inches of insolation and this area may have been an area difficlut to get to !

The room does suffer form mositure !

Thanks again

Mike

[Osem]

As others have said it's probably condensation, the effects of which have been made worse by the cold/damp weather and lack of ventilation. Vinegar solution can be used to kill mould and is safer to use than bleach. A dehumidifer would probably help a great deal.

[Rob]

Where was the insulation placed? In the roof void? Is the space above the insulation well ventilated? As warm air with moisture vapour rises it will make contact with the insulation and tries to pass through it. Eventually the temperature difference will cool the air leading to interstitial condensation within the insulation, or on top of it. If there is poor ventilation of the roofspace you could be seeing this moisture accumulating, saturating the insulation and causing the damp.

[DaiNasty]

Originally Posted by Rob

Where was the insulation placed? In the roof void? Is the space above the insulation well ventilated? As warm air with moisture vapour rises it will make contact with the insulation and tries to pass through it. Eventually the temperature difference will cool the air leading to interstitial condensation within the insulation, or on top of it. If there is poor ventilation of the roofspace you could be seeing this moisture accumulating, saturating the insulation and causing the damp.

That makes sense. If there is a pitched roof above this ceiling I'd bet the insulation has been pushed right out to the eaves and is blocking any ventilation. Condensation from under the felt is running down and producing the damp effect around the edge of the ceiling.

[Noggo]

Looking at the pictures, are those water marks on the ceiling (I've drawn lines on the pics attached for where I think I can see them).

If I’m right and not seeing things, I would think that there's a serious problem somewhere above. It could be anything already mention earlier in the thread by other people. I would have a look above the ceiling, in the loft space if there is one and on the roof to check any flashings, any valleys and roof covering. If it is a flat roof, I would recommend the use of some old boards or blanks to walk on to help spread your weight more evenly cross the roof, because if it is leaking the ply boards underneath will be a little wet and compromised in strenght.