White cement on block paving

[samantha urbanstone]

Ive spilt a bit of white cement on my new block paved drive, typically it was raining and now I have a white stain, Ive had a scrub at it but it wont be washed off, is there a chemical I can use? thank you Samantha

[simeonronacrete]

Hi Samantha

Off the top of my head and without being able to easily refer to my Technical Department (I'm in Hong Kong until the weekend), you could try some acid etch - although this may also attack the block paving. Builders merchants/specialist distributors may have more knowledge.

If our tech-guys know of any other solutions I'll let you know.

Regards

[samantha urbanstone]

thanks Simeon, I'll ask at the builders merchant,

love the way you dropped Honk kong into the post

thanks, Samantha

[Tony McC]

Probably easier to replace the stained blocks than to attempt cleaning. Depending on the type/brand of block, acid-based cleaning products can alter the colouring by reacting with the dyes, so it becomes a choice of either risking it or acid-washing the entire pavement. When it's just a handful of blocks, lifting them out and putting new ones in their place is a much easier option.

How was Honkers, Sim? I saw your staff resting themselves at the CityScape exhibition in London Village on Wednesday (yesterday). :;):

[simeonronacrete]

Hello.

HK is fine, hot, humid - 35 deg and 85% humidity. Just back from 2 days in China to see clients, major projects underway and hand out Mid Autumn Festival Lucky Lycee money packets to our admin, sales, production, QC and R&D Teams.

Off to Macau tomorrow for the day where the Las Vegas casino strip is being recreated with a huge amount of foreign investment. Gambling, illegal in China, is legal in Macau, which actually belongs to China! We are selling materials for tile bonding, colour tile grouts, waterproofing, screeds, repairs and bonding - all made in our China factory to ISO standards.

I fly back to UK on Sunday, arriving Monday morning. Interestingly whilst CityScape was reported by many to be lacking in visitors, we have had a lot of interest - as always - in Ronadeck Fast Grip, and also our new Eaze By Gum system Chewing Gum Repellent System to aid removal of chewing gum from paving.

For those interested in wind (and rain), you may be interested that Hong Kong currently has a T1 Storm Warning, with a T3 expected to be posted tomorrow. See
Hong Kong Storm Warning

Regards

[samantha urbanstone]

I could try getting some more, what about turning them upside down? is there an up and a down to these things??:D

[Tony McC]

Depends on the type of block, Samantha. Some can be inverted, some can't. Do you know what brand they are?

[AL_B]

Hi,

I have a similar problem. I had a large random pattern, flag patio laid recently, with a slate coloured border of block pavers, all around the edge. Looks great.

However the contractor, did not return to finish of the pointing and brushing in. There were quite a few small, but significant, gaps in between the block pavers, and also between the block pavers and the wall of the garage and house.

Not wanting water to get down the cracks, I decided to do the brushing in myself. Not a hard job.

So having consulted a DIY manual, I bought some kiln dried sand and a bag of cement. Made a dry mix of 3 parts sand and 1 part cement, and proceeded to patiently brush this stuff in.

Everything went well. But of course all the slate coloured edging blocks were now covered in a fine coating of dry mortor mix. Unfortunately the DIY book didn't say whether I should leave things as they were (i.e. dry), or wet it all.

I decided to wet it all, and hope it would wash away the mix on top of the slate coloured blocks. I even wiped them down with a towel. It seemed ok, with only some of the dry mix in the gaps being washed away. However the blocks have now got this "white" stain, despite my efforts of washing it off.

Surely there must be some way to return the blocks back to their former state. This must happen all the time when these blocks are laid, and a dry mix brushed in.

Thanks

Alan

[Tony McC]

An acid-based cleaner would remove most, if not all of the cement staining, but you run the real risk that the acid would alter the colouring of your block pavers and possibly the flagstones.

As I said earlier, it's often easier and less painful to replace the stained blocks with new than to hope an acid wash will rectify the problems.

Although I get to hear many tales of woe concerning cement stains on block paving, they come about because of a misunderstanding: block paving should NOT be jointed with sand and cement. It is designed and manufactured to be jointed with a clean, cement-free sand. Some eejits who ought to know better suggest using sand and cement because they fail to understand that it's friction that maintains the joints with block paving, not some hardened joint-filling material.

If and when you get the stained blocks put rigfht, joint them with clean, joint filling sand ONLY. Adding cement does them no good whatsoever.

[simeonronacrete]

Hey Samantha,

Why not either:

a. park your car over the dodgy patch
b. place one of your sculptures on the offending area
c. squint
d. move house

Sorry, I'm in one of those moods this morning!

Have a good one.

Sim

[AL_B]

Thanks Tony.

Looks like I've ruined them then.

Thanks for the advice though.

Alan

[samantha urbanstone]

Hey Samantha,

Why not either:

a. park your car over the dodgy patch
b. place one of your sculptures on the offending area
c. squint
d. move house

Sorry, I'm in one of those moods this morning!

Have a good one.

Sim

sorry I asked!!!

[Paverman Dan]

I love how Simeon gives us a travel update with each post. What a hustler . . . Go, Simeon, GO!

[samantha urbanstone]

dont encourage him paverman dan!!

he needs bringing down a peg or 2 if you ask me!!

[simeonronacrete]

Sorry folks, you must have the wrong idea about to me - it would be wrong to use this forum for anything other than it is designed for - and having just got back from Tenerife I don't have time to discuss anything but technical issues!