Light mould / moisture build up at window reveals

[Paul205]

Hi All,

I have added this question into the building section as I am unaware of where the root cause of this issue may originate.

We have a detached house, built in 1968 with a pitched tiled roof and wall construction which consists of outer brick, an air gap and inner block.

On the west facing wall we have first floor bedroom uPVC windows where in the window reveals light mould and then moisture builds on the paint which results in flaky paint and then a slow softening of the plasterboard. This occurs on both the side and upper reveal for both windows and it is predominantly where the plasterboard meets the uPVC window frames.

The issue was in place both many years before and the years after the fitment of replacement uPVC windows which were fitted in 2005. There have never been lintels in place in the outer brickwork but there are on the inner blockwork. The issue is not in place in any other windows but it does appear to affect a number of identical houses in our road.

I have attached photographs below.

I would be very grateful on thoughts on what maybe the root cause of this issue.

Many thanks




Paul

 

[jj4091]

Just a guess but I would suspect they may have been built without cavity trays above the windows. Or do you get a lot of condensation on the surface of the reveals. Or is it worse after heavy driving rain.

 

[Paul205]

Thanks for the response, I do not know whether cavity trays have been fitted, if they weren't how should / would water enter the cavity anyway

There is certainly no condensation issue JJ, certainly not

 

[^woody^]

Your images are not showing much, other than common skim and mastic cracking from thermal movement of the frame and maybe cooler edges of the reveal making the skim brittle.

I can't see any staining or signs of water penetration, or mould.

 

[jj4091]

Looking at the picture of the gable there appears to be something running along the mortar 2 courses above the larger window. Obviously I have no idea from looking at pictures but water can penetrate brickwork either through the bricks or mortat joints. Or it could be getting into the cavity at the verges. Have none of your neighbors had the problem investigated.

 

[foxhole]

I can’t see any trickle vents or other types?

 

[Paul205]

Perhaps the photos arent the best but around 2 years of repainting the plasterboard certainly begins to fail

 

[Paul205]

I can’t see any trickle vents or other types?

There are no vents above any of the windows in our house including the two windows in question

 

[Paul205]

Looking at the picture of the gable there appears to be something running along the mortar 2 courses above the larger window. Obviously I have no idea from looking at pictures but water can penetrate brickwork either through the bricks or mortat joints. Or it could be getting into the cavity at the verges. Have none of your neighbors had the problem investigated.

The white line appears to be silicon but this was installed by the previous owner. One neighbour seemed to feel that in his house the bricks and mortar above the windows had sagged due to a lack of lintels

 

[foxhole]

There are no vents above any of the windows in our house including the two windows in question

No ventilation = damp and mould