Leak or damp ?

[Bowness72]

Hi there, and thanks for any advice you can give....

I have some efflorescence on the brickwork outside my kitchen which I haven't noticed before.....

Damp patch

• Bowness72
• 7 May 2013
• 1

I haven't spent much time outside until recently so there is slight possibility it could have been there a few months but I think it's more recent.

Has anyone got any suggestions what they think might be causing it ?

So far I'm thinking....

Leak from washing machine, dishwasher (or kitchen sink as tap is very loose) ?
Has it been rebuilt at some point ?....because bricks look lighter than rest of wall (can't imagine why) and joints darker than elsewhere (possibly because damp).

I've also considered but discounted the following....

To do with decking as it's above dpc level but have investigated and joists don't seem to penetrate into wall.
Possible reduced under floor ventilation due to decking.
Leak from adjacent gully......but it's away from main staining.

I will be pulling washing machine out to investigate but thought I would post in the meantime to see if anyone has any other suggestions ?

Cheers

 

[dann09]

1. It roughly follows the deck and steps, is there a gutter leak/overflow splashing down onto the deck and steps?

2. I assume a cavity wall?

3. Do you have cavity insulation?

4. It's odd that the "inner" brickwork is lighter than the "outer" brickwork!

5. Could the hose pipe and hose-bib play any part?

6. As you suggested, carefully examine your plumbing supplies and waste - watch them in operation - esp the W/M standpipe discharge.
Examine the inside wall plaster for damp - the marks are about 600mm above corresponding FFL.

7. Is the floor suspended?

 

[Joe Malone]

Hi there, and thanks for any advice you can give....

I have some efflorescence on the brickwork outside my kitchen which I haven't noticed before.....

Damp patch

• Bowness72
• 7 May 2013
• 1

I haven't spent much time outside until recently so there is slight possibility it could have been there a few months but I think it's more recent.

Has anyone got any suggestions what they think might be causing it ?

So far I'm thinking....

Leak from washing machine, dishwasher (or kitchen sink as tap is very loose) ?
Has it been rebuilt at some point ?....because bricks look lighter than rest of wall (can't imagine why) and joints darker than elsewhere (possibly because damp).

I've also considered but discounted the following....

To do with decking as it's above dpc level but have investigated and joists don't seem to penetrate into wall.
Possible reduced under floor ventilation due to decking.
Leak from adjacent gully......but it's away from main staining.

I will be pulling washing machine out to investigate but thought I would post in the meantime to see if anyone has any other suggestions ?

Cheers

The clue as to what this is can be gained from the location and the pipe work. This isn't efflorescence, it's detergent staining from the waste outlet. Waste bathroom and kitchen water usually contains detergents from dishwashers, washing machines etc. Clearly the waste water is draining against the wall or the drain is blocked causing it to overflow and cause wall base damp.
As an afterthought, one thing that occurs to me is that the halo effect of the detergent staining would tend to indicate that the source of leak was more to the right of the drain, so either the drain is damaged or the waste water is tracking across to the right.

 

[masona]

I'm wondering if it's the high pressure gun with detergent when cleaning the decking then a quick blast up the wall?

 

[Joe Malone]

I'm wondering if it's the high pressure gun with detergent when cleaning the decking then a quick blast up the wall?

That's a really good thought if detergent has been used. I'm sure it's detergent but the staining is indicative of a long term damp problem rather than a one off occurrence.

 

[Bowness72]

Thanks for taking the time to look and comment guys. Having investigated behind the washing machine and dishwasher and checking the waste pipe/joints aren't loose, I have come to the conclusion the cause is something out of the picture. Directly above there are two holes in the fascia from where two overflows protruded before the current boiler was put in. Apparently these used to drip/run continuously so I believe the wall would have been continuously getting damp from splashback off the decking. The wall doesn't seem to be still damp either inside or outside so I think it's old staining but am going to borrow a moisture meter just to check whether or not it is actually still damp or not.

Cheers

 

[masona]

I'm wondering if it's the high pressure gun with detergent when cleaning the decking then a quick blast up the wall?

That's a really good thought if detergent has been used. I'm sure it's detergent but the staining is indicative of a long term damp problem rather than a one off occurrence.

I think you're right but have noticed the bottom brickworks looks cleaner but the mortar joints is darker than the rest.