Effloresence above DPC

[crazylarry]

Hello. I have effloresence above the DPC on a passage way wall. This wall is not exposed to the elements, therefore no moisture comes into contact with the wall face. Does the DPC need redoing? Is the moisture coming from below or above?

Cheers

Matt

 

[r896neo]

Efflouressence is not indicative of a damp problem.

 

[davebelushi]

Efflouressence is not indicative of a damp problem.

it can be.

 

[crazylarry]

Two differing opinions! Best to get it checked out anyway?

 

[r896neo]

As belushi says it can be an indicator of damp but the way your post read seemed as if you were sure it was and i just wanted to let you know that don't start worrying unnecessarily that this definatly meant you had a damp problem.

The moisture in the air or moisture tranfering horizontally through the wall is more than enough to cause it.

What's happening on the inside? Have you noticed any damp trouble?

 

[crazylarry]

As belushi says it can be an indicator of damp but the way your post read seemed as if you were sure it was and i just wanted to let you know that don't start worrying unnecessarily that this definatly meant you had a damp problem.

The moisture in the air or moisture tranfering horizontally through the wall is more than enough to cause it.

What's happening on the inside? Have you noticed any damp trouble?

Not really. Those pictures are from my passage. On the inside is the chimney stack. I'll take it off with a wire brush and see if it recurs.

 

[r896neo]

have you recently closed up the fireplace?

 

[^woody^]

[ On the inside is the chimney stack.

Well there is you answer then

Moisture from the flue (whether it is in use or not) is causing it

It will come back if you brush it off. Its a phenomenon, not a problem, and there is no quick remedy

 

[crazylarry]

There's an air vent on the inside of the stack in the room. The stack backs onto a passage so I've just put in an air brick on the passage side. I plan to close the vent in the room.

 

[r896neo]

yea it is various salts in the chimney stack leaching out, it has probably appeared recently because of a change of some sort hence why i asked about the blocking up a fireplace. Its nothing to worry about but if the flue is no longer in use best to cap it with a vented cap