jazzys

Hi guys, just wondering if anyone has any idea how to fix this problem with the back patio. Sensible answers only please.

there was a small spa type pool there and it looks to me like the paint has been bleached by the chlorine.

Is there a remedy bar painting each individual patch on the whole patio?

Hino

It looks as though it was a "handyman" who did the original work.

You are probably right about a spa or something similar being there originally. It looks as though the spa has been filled in, and stamped concrete has been used in an attempt to hide the joint between the existing slab and the spa infill material.

The two different materials ( spa infill & slab ), seem to have different absorbtion rates and this is causing the 'banding' that you can see in the photograph.

I'd call in your local decorative concrete mob and get their opinion on the cheapest "professional" fix.

Though if you want a cheap DIY 'handyman' job, buy a large tin of concrete paint, and forget about the 'decorative' pointing highlights..... ie paint it all one colour

Wol

I take it that the spa was an above ground one, standing on the circle?

If so, I can't quite see why chlorine should have caused such a perfect circle: I would hazard a guess that it's been protected from the sun and the rest of the pressed concrete has darkened.

If so it might be that the lighter area will darken gradually. Are there any other areas that were shaded and show a similar light appearance?

Three approaches:

1) Just leave it and see if it darkens.
2) Make a "feature" of the circle by painting it with say a matt glaze.
3) Painting over the whole patio, joints and all, with an exterior floor paint. I did that with a pool patio - it will need doing every three or so years though to keep it looking fresh.

jazzys

The spa was only there for about two months over xmas apparently. Yeah an above ground job.

I'm hearing ya about the perfect circle, i thought that myself but the chlorine bleaching of the paint was the only thing i could come up with.
Couldn't really see how the covered bit might be lighter if the uncovered remained darker. Sun bleaches doesn't it, not darkens?

I suppose painting it all one colour is an option but the drive is in a similar style so may look slightly out of place.

Is it possible to give it a good pressure blast down and re-paint each and every "stone" and thern reseal?

Not that i want to do it, just wondered if it would be a decent fix.

Cheers
Jazzys

Deancm

The uncovered area gets dirty from wear and tear, grime, dust etc. while the covered area under the spa remains protected and keeps it in an as new condition. You could always sand blast the dark areas to bring them up as new.

spartacus

Is the patio new? I can only think that the conditions under the spa (warm / humid) have drawn out more efflorescence (salts) from the concrete if its is newish. I'd power hose it all down with a concrete cleaner and leave it to settle for a month or so before doing anything else . . . let it settle down a bit.

Edit: On looking a bit closer, I think that's what it might be, as it affected the raw concrete as well as the paint effect 'pavers'.

http://www.duluxprotectivecoatings.c...lorescence.pdf

http://concreteconstruction.net/indu...ticleID=233348

lesleys

Just try pressure hosing the dark stuff around the edge of the circle to see if it can be cleaned to match. If it works then clean as much as you like. Don't do anything permanent (paint, seal etc) to only part of the surface or your mismatches will multiply.

jazzys

I'm afraid your barking up the wrong tree guys. I understand that the uncovered area might get dirtier than the covered but there couldn't possibly that much difference in a couple of months. And every inch of the patio is the same colour apart from that one circle.

The patio isn't particularly new, maybe 5 or 6 years i believe. Although whether the heat of a spa might still brings salts or whatever to the surface after such time i don't know. Although if it had been newer i could see where you might be coming from.

Power hosing it hasn't affected it at all. Its just like the covered area has been lightened a shade or two and i could only think it would have been a bleaching effect by the chlorine. BUT, i'm not even sure they tenants had chlorine in the pool / spa.

Cheers guys

Jazzys

spartacus

I think I'd have a go with a little white vinegar. The second link on previous posts mentions that effloresence is insoluble in water, but can still be removed with an acidic solution.

Edit: I'm thinking that, if it is efflorescence, its probably trapped under the sealer coat used when the paint effect was laid. Have a look at this datasheet.

http://www.aquamix.com.au/pdf/problem-solving/PS05.pdf

If it is, then its a right bitch on removing the sealer . . . as this datasheet lists.

http://www.aquamix.com.au/pdf/problem-solving/PS08.pdf

jazzys

After reading those links i was thinking vinegar myself to be honest, but the question is does efforvescence occur in concrete 5 or 6 years old?

Jazzys

spartacus

I think it can. Its not entirely to do with the age of the concrete, but the environment its being exposed to. Because of the difference in humidity under the spa, its changed the equilibrium of the concrete and drawn more salts to the surface . . . its a bit like a 'cup ring' on a timber table.

This was a decent link on youtube (efflorescence is from about two minutes on) and it gives a link totheir website which might yield more suggestions.

http://www.youtube.com/watch?v=m4uys...eature=related

jazzys

Thanks mate, may be worth trying a drop of white vinegar on it then eh.

Jazzys

spartacus

Trying the vinegar will tell you whether its on the surface, in which case you should be able to remove it, or whether its trapped under the seal coat, in which case you won't. Either way give it a try on a small area.

jazzys

Gotta be worth a try i reckon. It i can get rid of it with vinegar and a stiff wire brush followed by an all over pressure wash i'll be over the moon.

Thanks for your input. Just curious, have you ever come across anything like that before?

jazzys

spartacus

I think I'd be using nothing more than an old toothbrush. If the salt is on the surface the acid should dissolve it without the need for brute force.

Efflorescence is really common, you can see it on anything made using cement. I've never seen it make a distinct pattern like that before though.