I am hoping that someone with experience can help me. I had pavers laid 2 years ago with torpedo sand. Not much space between each paver. A year later, the crew came to adjust any loose pavers, clean, re-sand and seal the pavers. I had heard about the polymeric sand and asked that this product be used for re-sanding. Of course I asked their opinion, if they forsaw any problems, etc. No was their reply. I brought up that if more time was involved to use poly sand that I would certainly pay - no problem. I left for work in the morning and when I returned, my patios looked great. That night it drizzled, the following day it rained and the next day that is when I saw the white film. Long story short, the guy came out, took a picture and said he was going to find out what to do about it. Then he got busy, then it was autumn - so too cold I guess. Meanwhile, my friend's husband who used to install unilock told me to buy some Xylene and mop it on the pavers - this would "reactivate" the sealer and hopefully take the white film away. He said this had happened to him once and he believes it is moisture in the poly sand coming up from under the pavers. So I did it and it did improve some areas...but the area of the patio under all my trees didn't really change.
What can I do now? Sealer or not, all I really want is the pavers to not have the whiteish look. Doesn't seem like time is wearing the white film away either. Do I have to "strip" off any sealer that remains and re-seal? I almost wish I didn't have them use the polysand.
I have another issue with my retaining wall caps....white spots...won't wash away with cleaner...these were also sealed. Lots and lots of money and here I am....that's why I want to learn what to do and do it myself.
(There is one more issue with the patio, but I'll save that question...one side is sinking a bit..)
Thanks for any suggestions .......
bty, I live in Bloomingdale Il.
This is an interesting problem. Not interesting to you, I'm sure (probably very frustrating), but interesting to me, as it's one with a twist I haven't heard of yet.
That being said, here's what I can offer for info:
Xylene is a solvent, and your friend was likely correct about the "reactivation" (or maybe more accurate - remelting) of the acrylic sealer. However, re-liquefying the sealer did not address the issue of the minerals coming up through the pavers, so when the sealer re-hardened, the problem was still there.
Hindsight being 20/20, applying a sealer over pavers has a desirable consequence of hardening the joint sand, making poly sand not really necessary - a non-polymeric sand would have performed just fine if sealer was being poured over the top of it anyway. But I have my doubts as to whether the poly sand is what caused the problem.
The white film you're seeing is minerals (aka efflouresence) finding their way to the surface of the pavers, then getting trapped there by the sealer. But if the sealer hadn't been applied, you would still see that whitish film - the only difference is, it would wear off over a period of a few months (usually), or a few years (sometimes).
What I'd be more inclined to believe is that there's something at the site causing this problem other than the pavers, sand and sealer. Possibly some minerals in the soils or the crushed stone base that slowly worked their way up, and those last few rainfalls provided the lubrication/bouyancy to push the minerals to the top of the pavers.
You're contractor did right by you, waiting for a year before sealing the project. I used to recommend at least 90 days, for this exact reason - efflouresence sealed into the pavers can be exceedingly difficult to remove. And to help alleviate that problem, we've stopped offering that service altogether, instructing clients in how to apply sealer should they choose to seal their projects.
To the question at hand - "how do we fix this" - I don't have a clean, straightforward answer for you. The xylene can remelt the sealer again, but it would need to be removed from the pavers as much as possible once that was done, to allow the pavers to "breathe" and expel/wear off the minerals. The possible problems I see with that solution are, adding more solvent to the pavers would likely have the effect of pushing the sealer deeper into the pores of the pavers, making removal much harder. Next, complete removal of the sealer seems unlikely.
If there were some sort of acrylic binder that could be spread over the patio after re-applying the xylene, something that would combine with the acrylic in the sealer to make it easy to remove, that would help, but I'm unaware of any chemical that would do that (doesn't mean one doesn't exist; it just means I'm not a chemist).
So unfortunately, I think your best course of action for the next 2 years is no action at all. In time the sealer will wear off under normal foot traffic and allow the pavers to breathe again, and will likely expel the efflouresence. As a preventive measure, I'd avoid sealing the pavers in the future. If the minerals are coming up through the soil (do you have any whitish film on your home's foundation, or on any face brick?), it'll continue to come up for years.
What you are describing sounds like efflorescence, it is the salts from the concrete and aggregates coming to the surface. I'm not sure why the poly sand seems to have activated it, it might be coincidental. Unilock sells a chemical specifically made to remove efflorescence, I've seen it demonstrated and it works fairly well.
Thanks Stonehege and Pelican. Yes, I want to correct this situation, but I always jump too quickly - so your explanations help me slow down. I didn't think about the pavers being porous - and something to remove the xylene. I'm thinking to wait it out.
Funny what you said about the stone underneath. I had demolished a cement patio (20x12), but left quite a bit of the remains/gravel behind. After that, I put in a small room addition with a paver area on each side, connected by a 10ft paver walkway. The patio that hardly has the efflorescence was laid over the leftover cement patio gravel; the other patio area had new rock put in from the patio contractor. I'm not seeing any other white films around the house. Another big difference between the two patios is the amount of sun - problem patio had very little sun. I have since raised the canopy on my trees. Could it be that when the poly sand and sealer was applied the sand wasn't "set" or dry before the sealer was put on?
Or maybe if one uses poly sand and wants to seal, one should wait until the sand is entirely "set" or dry.
If that were the case, I would expect to see efflouresence appear also with paver patios that were not sealed. Since we started using polymeric sand on every single paver project we install, and haven't seen an increase in efflouresence problems (and have never seen it appear shortly after applying the sand), I have to think that the poly sand had little or nothing to do with the efflouresence, whether it was "set" or not. Something for reference - polymeric sand, whether it's the type that uses an organic or non-organic binder, softens a little and resets each time it gets wet (moreso with the organic binder variety) - so that sand is never really completely set.
So I do not think it's the poly sand.
From what you've said, the more likely explanation is that with heavier shade, water stayed in the pavers and base on the affected patio longer, allowing efflouresence to rise to the top. Because one patio has eff. significantly more than the other, I'm inclined to think it's the materials beneath that patio (crushed stone, etc) that have the minerals in them.
I should say again, from what I've read so far, I don't think this is something to be angry at your contractor for. By waiting 1 year, they were doing their best to eliminate the chance of efflouresence coming out of the pavers. And while the crushed stone or bedding sand they used may have been the source of the excess minerals, it would be hard for them to know about it unless they did a chemical analysis on the crushed stone they were buying from local quarries - something that I think should not be an expectation of a contractor. If they use crushed stone from one supplier and consistently have eff. issues, then they should consider re-sourcing their stone.
While it has to be maddening to feel helpless about having this patio with these belmishes and being able to do little about it, I think the best course of action is to do nothing, letting the sealer wear off in it's course, and allow the efflouresence to come out afterward.
Well, I've used plenty of Belgard products and they have just as much efflorescence as any other paver we've used. Although around here, you pay a little bit more for the Belgard name.
OK thanks. Was there something you did to remove it? How did your customers react to the efflorescence?
Now I'm wondering if mine will ever go away if it is coming up from underneath the pavers; seems to me that the efflorescence would return every time it rains. So waiting this out may not work. Maybe the only real solution is to pull up the pavers and re-do the rock and sand.
(Just so everyone knows, I am not angry with my contractor. I feel he and his crew did a good job and I would hire him again. I know I took a risk asking him to use polysand as he never used it before. So I am not blaming him at all. I know that nothing is perfect and things can happen under certain conditions.)
RickG, I notice in that document that they mention those steps to remove efflouresence should be taken before any sealer is applied. Because this project has been sealed, those steps aren't really efficacious.
As you say, I think time and tide are the remedy of choice in this case.
Old but interesting thread. I believe the whitish look you have is due to a couple of things that likely happened while the installer was sealing your patio.
1. Your patio must be properly acid washed and left to dry for approx. 2 days. If the entire process was done in one afternoon then the brick was likely damp when the sealer was applied. That whitish look now becomes a permanent feature to your patio.
2. If it was acid washed first then left to dry for 48hrs and you still have the white stains, likely the patio surface was too hot to seal. Again permanent feature. It could take many years to wear off then you could attempt it again but likely your best bet is to either replace the brick or just leave it alone and live with the stains.
My company no longer offers this service since it is too hard to plan.
Thank you Eastern1 - when you say acid washed, do you mean muratic acid, diluted? What would be the ratio of m. acid to water? I stopped by a landscaping company last summer and they recommended to use a power washer and very hot water (i think it was plain water, but may have been with some effl. remover) to try and remove some of the sealer. He also said it's tricky since you could remove color from the pavers. Any tips from the pros are welcome!
Thank you Eastern1 - when you say acid washed, do you mean muratic acid, diluted? What would be the ratio of m. acid to water? I stopped by a landscaping company last summer and they recommended to use a power washer and very hot water (i think it was plain water, but may have been with some effl. remover) to try and remove some of the sealer. He also said it's tricky since you could remove color from the pavers. Any tips from the pros are welcome!
Acid wash is a loose term, sorry I should of been more attuned to that. I have heard of hot water being pressure blasted on heavy effloresent stains, also you could use a techni-seal product called effl. remover. It would be the best. Stay away from muriatic acid, even diluted it will remove some color from the brick. Years ago I ruined an entire brand new interlock driveway with muriatic acid. I replaced the whole thing including two walkways at my cost. uggghh.
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