What is likely to have caused this water mark?

Phil3822

Hello all, I have recently had this pictured water mark appear. More recent the drips have dropped further and lower and it’s moving across the wall. It’s always looking wet and does feel it. This is in our upstairs main bedroom, it’s on an outside wall. As the house is a dormer bungalow there is a small roof space above barely accessible, that wall has PIR insulation behind the plaster board then its the membrane and tiles. No water pipes in the area. Appreciate any thoughts. 

[Deleted User]

Hi,

could be the colder more damp days now.

Is room ventilated in morning and a bit of heat later in day?

Bendy_House

Well, it looks like condensation to me - ie it appears surface-formed, and not from behind.

But, you reckon that wall is well insulated? I wonder if someone messed up so that the top edge is still way colder than other parts? If it's cond, then enough has formed to actually 'run'.

Or, it's a leak from the ceiling above.

Can you get to above that ceiling to see if it's from an outside leak?

FreeBear

Looks like condensation forming around the coving, and then running down the wall. Any idea what the humidity is like ?

diystarter7

A leak of the flashing joint  I suspect.

At times it may not show after a bit of rain and at others it may depending which way the wind blows.

housebuyer143

I lived in a dorma bungalow for years and as soon as we had a baby we had this all the time in colder weather. You will find the roof space area isn't insulated at all or barely.

Providing the roof is fine, it's condensation and a good dehumidifier will sort it right it. We used a meaco 123, super quiet and would put it on everyday for about 2 hours in the colder months and we never had a problem again.

Phil3822

Thanks all, we have lived here for 4 years and it’s happened twice. I will check the humidity of the room but generally the rooms are around 50 pc. Directly above that area are some roof hip tiles so I will check out the mortar too. It’s just so random, it first appeared beginning of October this year so very mild but we did have some heavy rain. All helpful comments to check out. 

[Deleted User]

A family member experiences this in their home, in their place it's when that room's door has been closed overnight with someone sleeping in there, also when the bathroom (next to this room) has had one of them taking an hour long bath - the other time is when cooking's been going on for hours ....
Yup, all this with barely a window open anywhere 🙄🤷‍♀️🤷‍♂️🤷‍♂️🤷

Eldi_Dos

Do you have trickle vents in window in that bedroom?
Have you redecorated recently and moisture more noticeable due to colour change or change from matt to vinyl finish?

Phil3822

Eldi_Dos said:

Do you have trickle vents in window in that bedroom?
Have you redecorated recently and moisture more noticeable due to colour change or change from matt to vinyl finish?

Yes we have trickle vents on all windows. We will leave open. And yes we have decorated within last 2 years and since this issue appeared but the previous colour was a matt grey so would noticed too. We have an en-suite shower room in that room which has an extra fan etc too. The windows do not get condensation so really was not thinking this would be condensation. Appreciate all the guidance. 

Phil3822

Again thanks for your advice, have just been and checked things out. 

In the loft above this area is an extractor pipe that runs from the bathrooms and out the house. Could not feel it and need a hand but will see if it’s wet. I have also put my hydro/temp gauge in there and it’s showing 67% moisture in the room. The room is slept in but not heated. It’s around 18c during winter and has two adults sleeping in it. I have now opened the window vents and velux vent. Door to the room is open all day and closed at night. Hope this allows some insight. Thanks again.