How to manage blooming on black bricks?

[233sqn]

Folks… I would appreciate your guidance on how to manage blooming on Black bricks

I understand that blooming is one of those things, but as ours seems to get worse by the year and is particularly unsightly on black bricks I’m looking for the best way to keep them clean and reduce the build up.

We have a black limestone patio, and it is raised with the vertical faces in a smooth faced black brick. It seems to me that rain runs off the patio via the grout joints and down the brick faces where it blooms causing thick crusty residue which is very difficult to remove. The patio is about 3 years old now and the problem seems to be getting worse.

Would it be an idea to seal the bricks to make it easier to get the deposit off on a regular basis for instance?

Any thoughts or suggestions welcomed!

[Tony McC]

I'm assuming these 'black bricks' are typical clay masonry bricks and not concrete pavers.

If so, you can get a proprietary eff cleaner at most BMS and use as directed to get rid of the current bloom. Once it's all been perfectly dry for about 3 days, you can use olive oil to coat the bricks and that *should* prevent any further bloom this year.

Note that this is a temporary fix because the olive oil breaks down over the summer and you are, effectively, back to square one. Some of the specialist masonry sealants claim to prevent eff and/or lime formation from run-off, but I haven't really tested any of them so I'm not sure just how effective they are. A mate of mine in the fireplace business swears by them, though.

[233sqn]

Thanks for the advice.

Having studied it a bit closer, I think the rain water runs off the slabs and then around the edge of the slab where it then meets the mix that the slabs are laid on, and it’s here that it picks up and creates a sort of calcium looking thin sludge that runs down the brick faces.

I’m wondering if I should just seal the exposed edge of the bedding mix with some white PVA?

[GB_Groundworks]

pva is water soluble ergo feck all use as a seal against water

[Tony McC]

SBR would be better than PVA for the reason Giles mentions, plus the fact that it's an all-round tougher product, but whether it would solve the problem, I can't say for sure.

Still, given you can get a five litre pack for around a tenner, iand that it can't make matters any worse, it's probably worth giving it a go.

[mark_buildnrepair]

SBR on its own won't do much. It needs to react with cement to be of any value. And clearly you won't want to be sploshing a through coloured cement SBR slurry onto your pretty bricks. And neat SBR can yellow on exposure to UV light. So a definite no-no on a white surface!

Efflorescence is a function of water, soluble salts and evaporation. Trapping those salts inside the bricks with a strong sealer can result in the bricks "blowing", with the pressure of entrapped salts struggling to get out. Allowing the salts to leach out, and then cleaning the brick face, is probably the way to go. Over time less efflorescence occurs unless there is some other source of salts. For more information see: Article

Continual cleaning is probably the way forward. Unless someone else knows different?!