damp kitchen wall

[daveaspy]

Any idea what is going on with the damp in this wall?

View media item 66395
This is above the kitchen worktop and looks like rising damp since the electric socket seems to halt the damp at that point. This goes around the corner onto the next wall for about the same distance again. Then the bit of damp on the window reveal - is it connected? The two patches dont touch but they are very close.

I just dont know why it is so damp. It will go away and leave a tide mark then a few weeks later come back again. Cant see anything leaking underneath the kitchen units. Outside is a gutter drainpipe that isnt leaking. There are a few bricks with pointing in need of renewing but with large eaves the wall doesnt really get lashed with rain.

I have a little weather monitor in there an it reckons current temp is 16C 86%RH - but then it is chucking it down outside!

 

[dann09]

1. I notice that your window frame has been installed, presumably, flush with the outside brick face - (is it brick, or something else?).
Perhaps you could check the caulking?

Moisture might be bypassing the frame and crossing the cavity?

Moisture can penetrate in one place and manifest in another.

2. Do you have cavity insulation - original or injected?

3. Have you investigated the lower wall (and floor if possible) behind the base units for signs of damp?

4. Pics of the exterior & a larger view of the kitchen would help.

5. Where are your wet appliances located?

6. Does any wet pipework or waste run behind the base units?

7. When was any bldg work last done in the kit. or above the kit. or outside the kit?

 

[joe-90]

He's got a leak. It's obvious.

 

[tony1851]

Is it an old house?
If it's been treated for rising damp some time in the past, they may have replastered the lower part of the wall in a cement/sand mix in an effort to suppress any damp.
This can cause condensation when the humidity is high.

 

[daveaspy]

I'll try and get some wider pics later but at work now. So, a bit more background

1930's red brick semi
The window is almost flush with the outside but sure the caulking looked ok. The outside of the wall doesn't really get the rain and these marks have been coming and going throughout the year even when we had long dry spells so I dont think it is penetrating from outside.
It is a cavity wall with blown fiber insulation (I think! white stuff, not solid like foam or separate like polystyrene balls)
In the corner to the left and above is the gas boiler.
Underneath is the washing machine and to the right the sink.
There are water pipes running along the bottom of the wall to the appliances
There are water pipes running floor to ceiling in the corner taking hot&cold water to the bathroom above.
The floor is solid (concrete I assume?) in this part of the kitchen.

I had some problems with musty smelling units and pulled off the kick boards under the units earlier in the year to investigate. The exposed cold water pipes had big drops of condensation hanging off them as the pipes were not insulated. Having dried them and left the kick boards off for ventilation those pipes now seem dry. There doesn't looks to be visible dampness on the wall at floor level, but really, that is hard to tell without ripping out the units. If I had a leak there would be puddles somewhere, no?

 

[joe-90]

Bet it's a leaky pipe encased in concrete. Seen loads of those over the years.

 

[daveaspy]

hmm, leaky pipe encased in concrete - dont like the sound of that

I can see the water main rising out of the solid floor underneath the sink unit - that is on the right hand side of the window. The pipe is lead as it comes out but converted to copper after a few inches then the stop tap. No idea where the water main goes under the floor - would it normally go under the wall then down the drive to the road or though the inside of the house and exit at the front? I can not find any external water stop tap near my property although most other houses in the street seem to have one.

Any idea how to prove or disprove this possibility?

 

[TheVictorian]

Can you take a brick out behind the units and see if the cavity insulation is wet?

Is there any staining on the outside skin of brickwork?

 

[TheVictorian]

It is also possible that your water pipe is a shared supply so runs under the floor to next door and then down next door's drive to a stop tap that covers both properties.

 

[daveaspy]

Can you take a brick out behind the units and see if the cavity insulation is wet?

Is there any staining on the outside skin of brickwork?

yeah thats probably not too much trouble - thanks