White fungus

[Jb]

A recently built wall has just started showing signs of the white fungus you sometimes see on old walls. I understand it's something to do with salts in the bricks but this has started in the mortar. There are five patches about two inch square at the moment and I'm wondering how to stop it spreading, if that's at all possible. If I removed the surrounding mortar and repointed will it come back or am I wasting my time and just have to keep scrubbing it off? Googling the problem seems inconclusive on a solution.

Thanks

Jb

[The Natural Philosopher]

Its not a fungus. Its efflorescence. Google it.

[newshound]

Inside or outside wall? Earth on one side? New or old bricks?

I doubt if repointing will make any difference, just remove it with a wire brush every time it gets annoying.

[Andrew Gabriel]

A wire brush can easily mark the brickwork. Diluted brick acid will dissolve it, but you don't want to do this too often as it will also damage the mortar eventually. Brick acid must be well rinsed off afterwards, and also beware of any fancy surface along the base of the wall in case it is damaged by the brick acid.

Even rain will eventually dissolve it, but only very slowly.

[The Natural Philosopher]

3-6 months of winter rain and it will all be gone.

or pressure wash it a few times

[Jb]

Thanks for replies and I should have said it's an outside wall around a patio laid with Indian sandstone? so didn't fancy the idea of spraying acid around. I have a small pressure washer so I'll use that every couple of months or so and see how we go. At least your advice saved me the wasting my time and trouble repointing..

Thanks

Jb>

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[Brian Gaff]

Well its all the strands of the growth that go in deep into the structure. Not sure its going to be an easy fix. The thing must be using something there to feed on. Brian

[Chris Hogg]

A neighbour recently had their roof re-slated, and the ridge tiles were mortared into place. Within a couple of weeks, the roof looked very unsightly, with white deposits streaking down from the ridge. Six months later they had all dissolved away. I remember many years ago my school chemistry master saying that mortar efflorescence was a sign of good quality cement.