severe damp problem above a window

[donmaico]

I am at my wits end with this because i cant figure out where its coming from.We have had a number of jobs done on the wall where the window is situated including replacing the window itself ,because of a constant issue with damp penetrating from the a outside ,The wall itself is brick double skinned with a cavity which has been filled with insulating polystyrene beads although the damp issue was there well before they were put in.
The outer skin of the wall has been painted which doesn't seem to act a s barrier to driving rain.
When we first moved into the house we had the areas around three windows on the wall replastered because it was literally falling off.We also had the trays over the windows replaced and new weep holes installed.Now that has worked for two windows but not the other.Any holes or gaps that we could find in the brickwork we had filled in and checked the guttering to see if that was blocked and it wasn't.
Had two building surveyors round who could not enlighten me the builder I used has obviously not cured the problem so i really don't know where to turn to.Another builder, structural engineer or damp proof consultant? Can anyone suggest what I can do? Thanks

 

[stuart45]

Can you post some photos of the inside and outside?

 

[donmaico]

Can you post some photos of the inside and outside?

here are some photos I took.One is of the wall immediately above the window,two on the inside showing the damp in the recess and to the right of the window and then the other two to shops where remedial work was carried replacing tray and installing plastic weephole pipes.
I have since discovered that the other two windows are affected as well although not to the same extent
what worries the most is the fact the lintels we have on the inside skin are made of oak so there could be rot issues there

 

[donmaico]

Can you post some photos of the inside and outside?

//www.diynot.com/network/donmaico/albums/18935

I couldn't figure out how to add the pictues into my reply so I just put this link up instead

 

[tony1851]

Could it be 'cold bridging', whereby condensation forms on parts which are less-well insulated (and hence colder) than other areas. Metal lintels can cause this.

PS
There doesn't seem to be any lintel on the outer skin, judging by the headers over the window frame. When new plastic window are put in, the weight of the brickwork can cause them to bend downwards a little, possibly opening small (hairline) cracks in the brickwork above. This might be where rainwater is getting in and running down?

 

[donmaico]

Could it be 'cold bridging', whereby condensation forms on parts which are less-well insulated (and hence colder) than other areas. Metal lintels can cause this.

PS
There doesn't seem to be any lintel on the outer skin, judging by the headers over the window frame. When new plastic window are put in, the weight of the brickwork can cause them to bend downwards a little, possibly opening small (hairline) cracks in the brickwork above. This might be where rainwater is getting in and running down?

actually when the fitters fitted the windows the brick lintels did move downwards somewhat so i had to get a builder to repoint the gap just above it.As for the cold bridging we had one of the oak lintels replaced with a steal and although that has damp issue as well its nothing like as bad as the one on the photo.
If there are small hairline cracks as you suggest maybe I could cover the brick face with a cement slurry then paint over that ,have the wall repointed or have it rendered with one those new system renders that don't crack, but before I do any of that I have to ascertain what is actually causing the problem.

 

[Alastairreid]

Looks like condensation caused by cold bridging!

 

[donmaico]

Looks like condensation caused by cold bridging!

yes but the odd thing is that the worst affected window has no metal lintel over it ,rather an oak one and on the top right of it the paint seems to be peeling somewhat and its very damp .I guess the bridging could be caused by the insulation we had installed , something that we were required to do by the local authority in order to comply with building regs re a new extension we had done.I guess if that is the problem its matter of how one removes the insulation.

 

[Alastairreid]

The insulation will not create a cold bridge unless it gets saturated and slumps to create localized pockets of dampness.

Personally i would try an insulated plasterboard over all the affected walls.

 

[donmaico]

The insulation will not create a cold bridge unless it gets saturated and slumps to create localized pockets of dampness.

Personally i would try an insulated plasterboard over all the affected walls.

the tray and weep holes should cope with any water than falls on the trays but from what i can make out that doesn't seem to be happening , in which case the insulation beads could well have slumped and become saturated. The plaster in the window recess at the top and to the immediate right of it, feels quite wet
I am using a dehumidifier now and shall open a window slightly to see if that helps at all

 

[stuart45]

I have seen problems when the tray was sitting on the brick above the frame instead of the frame itself.
Only in really heavy rainfall, enough water could get through the soldier, or brick on edge to cause dampness inside.

 

[Architexeter]

What is the orientation?Ddoes this wall face the prevailing wind/rain? Full fill cavity wall insulation can easily cause these defects/exacerbate previous defects but nomally only on an exposed elevation.

 

[donmaico]

What is the orientation?Ddoes this wall face the prevailing wind/rain? Full fill cavity wall insulation can easily cause these defects/exacerbate previous defects but nomally only on an exposed elevation.

yes it does face the prevailing wind /rain, but when we bought the house and there was no insulation the problem was evident then because we had water coming in and the plaster in the top part of the recess was literally hanging off.It was then that we decided to replace the trays

 

[donmaico]

I have seen problems when the tray was sitting on the brick above the frame instead of the frame itself.
Only in really heavy rainfall, enough water could get through the soldier, or brick on edge to cause dampness inside.

well yes its sitting on top of what is in effect the brick soldier lintel

 

[donmaico]

I am thinking of having a render system such as this on that one wall.Its not in an immediately visible side of the house so it wouldn't matter so much if it was at odds with the rest,I understand some renders can provide a "painted brick" finish anyway.

http://www.wethertex.co.uk/external-rendering/

As for the cavity wall insulation issue it just seem that opinion is very divided as to whether it does cause problem .If I could say with absolute certainty that it does i would have it removed , problem is it was there already before I had the stuff injected.
As i see it the bricks used in the construction back in the 30s were of low quality and the pointing mix used was rather weak,This has resulted in some of the bricks spalling and the pointing literally crumbling away in some parts particularly in the lower levels of the wall ,where I had it replaced.
Painting the wall only serves to seal any water than gather inside so it can only go in and not out.Thats why i am now think in terms of sandblasting the paint off and applying a modern render system over that one wall