Black mold behind the washing machine

Emily_Joy

There were washing machine and dishwasher in the kitchen next to each other and next to the cupboard under the sink. The vendor removed the washing machine but left the dishwasher. It turned out the wall behind the washing machine was just covered with black mold. The mold seem to continue to the corner, in the direction opposite to the sink and dishwasher, but not behind the dishwasher. This is the external wall and on the other side there is a firewood shed. 

I presume the causes of the mold could be (1) the lack of ventilation (2) water leak  (3) penetrating damp. The house has a DPC installed. How to diagnose the problem? 

The new washing machine is due to arrive this week.

Jonboy_1984

Can you provide pictures of the plumbing arrangements for the waste water from the washing machine?

(At our old property there was a vertical pipe you simply pushed the washing machine waste pipe into and that periodically overflowed when pumping water out of the drum)

FreeBear

Emily_Joy said: I presume the causes of the mold could be (1) the lack of ventilation (2) water leak  (3) penetrating damp.

4) condensation.

Likely to be a combination of ventilation and condensation on the cold(er) exterior wall. An old water leak may have been a contributory factor, especially if the wall wasn't washed down after fixing the leak.

Increasing air flow behind the washing machines is not going to be easy. Reducing the humidity will help, but in a kitchen, this isn't going to be easy either. Short of going to town insulating the wall, I don't have any low cost suggestions.

Emily_Joy

Jonboy_1984 said:

Can you provide pictures of the plumbing arrangements for the waste water from the washing machine?

(At our old property there was a vertical pipe you simply pushed the washing machine waste pipe into and that periodically overflowed when pumping water out of the drum)

I took some photographs earlier today. Under the kitchen sink:

Emily_Joy

The wall behind the washing machine, after it has been washed with mold killer:

Emily_Joy

The wall behind the dishwasher. On the right is the cupboard under the kitchen sink.

Emily_Joy

A view to the left from where the washing machine used to be, behind another (currently empty & dry) cupboard.

Emily_Joy

I think I figured out the reason for the mold: all water that comes on the top of the wood shed is just poured into the wall. Now I need to find a solution...

FreeBear

Emily_Joy said:

I think I figured out the reason for the mold: all water that comes on the top of the wood shed is just poured into the wall. Now I need to find a solution...

Pull the wood store a good foot or two away from the wall. Better still, modify the roof so that it slopes the other way (and I'd still leave a ~300mm gap).

kipsterno1

This wouldn't affect the black mold but shouldn't the waste pipes from the dishwasher and washer be fed in higher than they are? 

Gavin83

kipsterno1 said:

This wouldn't affect the black mold but shouldn't the waste pipes from the dishwasher and washer be fed in higher than they are? 

Yep they should be. The waste pipe should be fitted so a part of it is higher than the sink.