oh no they've gone mouldy

[fluffytail10]

Help, my lovely, recently exposed, pamment/brick floor is going mouldy. It is really good, old fashioned furry white mould and is covering a few floor bricks in the kitchen. It is very damp there so I'm not surprised. How can I get rid of it? I guess it will go as the floor dries out but is there a solution for now? Only some bricks seem to be covered, others are fine. Have tried wiping it off but it comes back.
thanks

 

[MdB]

Sounds like it is efflorescence to me rather than mould. This will be salt crystals left behind as moisture evaporates from the surface of the brick.

I has quite a good crop when we removed a bath:

Whilst evaporation continues, I not sure there is a lot you can do apart from seal it and the moisture in - probably not what you want to do. In our case, once the wall dried out, the efflorescence stopped as there was no moisture to transfer the salt.

 

[Penners]

I think MdB may well be correct about this being efflorescence - salts coming out of the flooring bricks because of the damp. I echo what he said: don't be tempted to seal the floor - this will just trap the moisture and the salts in it.

There are various levels of treatment for efflorescence. The simplest and safest is just to use a stiff brush to brush it away. It will almost certainly reappear, so you just need to keep doing the brushing periodically until (a) the salts have all leached out and/or (b) the damp has dispersed. The salts are water soluble so you can wash or hose them away, but this is somewhat self-defeating as you can drive some of them back into the brick, and encourage dampness.

An old brickie once told me that you can deal with mild efflorescence by peeing on it! The problem with this is that, if you have extensive efflorescence to deal with, you may find yourself paying far too many visits to the pub in order to generate additional supplies of the treatment.

But the principle is right - efflorescence is alkaline, so you need acid to neutralise it. You can use dilute hydrochloric acid, but personally I would regard this as a last resort. Not only is it dangerous stuff but you're also putting moisture back into the bricks that you're trying to dry out. If you do decide to resort to acid, I should try something mild first - white vinegar, for example, or kettle descaler.

 

[fluffytail10]

Nope sorry looks like mould to me :?





We have plenty of inflorescence too, which we're brushing away and ignoring.
thanks

 

[fluffytail10]

sorry effluessence

 

[fluffytail10]

well you know what i mean :roll:

 

[Penners]

...inflorescence...effluescence, let's call the whole thing off. :wink:

It's pretty difficult to tell from those photos whether it's efflorescence or mould. It could even be that your tail is moulting.

If you really believe it to be mould, try scrubbing it with a mild solution of bleach. Be sure to dry it off afterwards as thoroughly as possible, with old towels.

Be sure to try a small test patch somewhere insignificant first - just to be sure that the bleach doesn't take any colour out of the bricks.

 

[worms]

It might be the linseed oil that you put on them. I'd just polish off the mould and after a couple of times it probably won't come back. Or rub the tiles down with a little white spirit and buff them up.

 

[fluffytail10]

thanks worms - i did wonder if it is was the linseed or beeswax!

 

[Flyfisher]

Could there be both problems here? The first photo definitely looks like efflorescence and the second one definitely like mould.

 

[worms]

Could there be both problems here? The first photo definitely looks like efflorescence and the second one definitely like mould.

To my eye, both of fluffytail's photos are mould. The first one, labeled "mouldy brick", you can see the classic round colonies, with the raised, older, central portion which is sporing nicely and if you zoom in you can see that (just like an old loaf of bread) you've got a mix of a white species and a blue species. They'll only grow where they are undisturbed and have a suitably nutritive substrate. Regular polishing solves the "undisturbed" bit and a rub down with a cloth dampened in white spirit will help remove any excess oil or wax which might be providing the nutrition.

 

[Zebra]

Does mould like oil/wax then? Would have thought that oiling something would protect against mould. Not questioning what you say, just wondering. Come to think of it though, my Mum's oiled leather saddles used to go mouldy if they were left damp. That is to say, I mean my Mum's horse's oiled leather saddles....

 

[Flyfisher]

Oil and wax are hydrocarbons and can provide adequate nutrition for some organisms, though they also need a source of water as well. It depends on the exact type of oil, but linseed oil seems to be a bit of a favourite 'dish'.

Perhaps surprisingly, diesel fuel tanks are also susceptible, especially if the tank becomes contaminated with water, which is not all that uncommon due to condensation. http://www.howcleanisyouroil.com/DIESEL-FUEL-BUG

Life can be remarkably adaptable.

 

[Penners]

Good grief! I didn't know about "diesel fungus"!

I'm aware from personal experience that vegetable oils can support the growth of fungus - our oiled garden bench has to be pressure washed every couple of years to get rid of black growth on it. And I suppose mineral oils aren't actually that different from vegetable oils (being, as they are, created originally from prehistoric vegetable matter).

 

[MatthewC]

Oil and wax are hydrocarbons and can provide adequate nutrition for some organisms, though they also need a source of water as well. It depends on the exact type of oil, but linseed oil seems to be a bit of a favourite 'dish'.

Perhaps surprisingly, diesel fuel tanks are also susceptible, especially if the tank becomes contaminated with water, which is not all that uncommon due to condensation. http://www.howcleanisyouroil.com/DIESEL-FUEL-BUG

Life can be remarkably adaptable.

You get cladisporium resinae in (jet) aircraft fuel tanks as well. It's a well known problem, hence the need for regular fuel system water drain checks. In the RAF jet fuel has some stuff called "Fuel System Icing Inhibitor" which had the useful side effect of also inhibiting the fungal growth. I would hate to make people worry about commercial flying, but I don't think airlines use it due to the extra expense...

 

[worms]

There is also Helaeomyia petrolei the Californian petrolium fly, whose larvae live in crude oil, feeding on other insects that fall into the oil.

 

[Penners]

You get cladisporium resinae

I think I caught that once from a Greek waitress.