Polymeric sand problems - please help!

[bellea3]

Hello,

We had a clay-paver patio installed two years ago. The contractor used Envirobond sand in the joints. This turned out to be a problem because the patio gets a lot of shade and the sand was staying moist most of the time, so we had a lot of weeds, grass, moss, anthills, etc. So the contractor attempted to remove the Envirobond sand by powerwashing the patio, and then filled the joints with standard polymeric sand that would stay hard. However, this was difficult to do because the clay pavers were chipping, and they were unable to completely remove all of the sand from between the joints. (I also don't think they very thoroughly refilled the joints when they were done.)

This year, we were still having a lot of weeds, ants, etc., and many of the joints seemed to have plain old dirt in them instead of any type of sand. So two weeks ago, we tried again with another contractor - he powerwashed it and reapplied polymeric sand. This time, it seems like the majority of the new sand never hardened at all and has since washed out of the joints. After every rain, we've had a patio covered with loose sand, and we don't seem any better off than we were before. My understanding is that this is because not enough of the old dirt/sand was removed from the joints to allow the new layer to harden (and I don't blame the contractor for this - due to the chipping issue, I told him not to powerwash too much).

So, if we can't powerwash to remove the old dirt from between the pavers, what options do we have? Is there ANYTHING we can do at this point other than pulling up the entire patio and starting over (which the original contractor is refusing to do, so it's not really an option for us)? Are there any alternatives to polymeric sand for minimizing weeds, ants, moss, etc.? Yearly spraying of some sort? Thanks so much for any suggestions you may have.

[teacher]

This is a tough problem. The only efficient way to get the sand out of the joints is to pressure wash. If chipping is a legitimate issue, however, the next best thing would be to just use a hose and try to wash the sand out. I doubt if that would completely empty the joints, though, especially if an organic stabilizer was used that is designed to re-activate when saturated. Might be your only option.

If organic stabilizers will not work for you because of the shade and constant dampness, and polymeric won't work because you cannot fill the joint deep enough for more than a scab to form, then maybe you could try a penetrating sealer/joint stabilizer. Normally, this isn't recommended with clay, as it is important that clay be able to breathe. There are products on the market, however, that CLAIM they are breathable and can be used on clay. Make sure the label states that this is possible. These products are rolled or sprayed on like a sealer but offer joint stabilizing benefits as well. Your patio would have to be completely dry prior to application or you could expect inconsistent results. The joints should be filled after washing with regular "concrete sand." Do not use organically stabilized sand (i.e. SandLOCK, Envirobond) prior to application of sealer. Mold issues can develop. Then, once dry, the sealer can be applied. This should help in stabilizing your sand and maybe help clear up any mold/mildew issues you may have with the area being constantly damp.

Good luck!

[sandman]

Teacher is right on about companies 'claiming' their products can be used on clay AND offer joint stabilization. Unfortunately, this is false! Sealers can not offer breathability and stabilization without compromise. I am assuming that these clay pavers do not have any spacer bar on the sides of the paver themselves to offer a 1/8" gap, or else the power-washing would be more effective without chipping the clay. Like most polymeric applications gone bad (which happens FAR too often) I would bet the contractor activated the joints with too much water, thus causing the acrylic beads to wash away. Polymeric sands are a pain, and they have a short lifespan even when applied properly. Organic stabilizers work much better, but not in this typ of area. You have a problem with many side effects. Eliminating mold can be done without sealers and stabilizers, by applying ammonium sulfamate to the joints (can be purchased at garden supply stores) A powdery deposit is expected soon after, but this can be cleaned off by washing with water. This has been known to reduce, but not eliminate, ant infestation as well. Though this would not help the wash-out issue, which seems to be the biggest problem. Stabilizers have become extremely common these days, although not completely necessary. Your larger issue would be the lack of surface tension created within the pavements field. Many factors can be caused by this (poor edge restraint, improper base installation, etc) but can often be due to lack of compaction once the joint sand has been swept into the joints. This can be even more of an issue with clay pavers, when contractors are more worried about cracking the pavers from a plate compactor. But without his necessary step, surface energy will never truly be acquired. I would be willing to bet that wash-out would be greatly reduced if a very thorough sweeping of joint sand, compacting, sweeping, compacting is performed with a urethane mat under the compactor to reduce/eliminate surface cracks and chips.

[teacher]

I agree with many of the things that Sandman suggested. Maybe try a thorough joint fill and compaction again, as he suggested, and if you still experience the same problems, then the last alternative may be trying the stabilizer/sealer. I'd love to hear how it all goes.

[bellea3]

Thanks for all of the suggestions - the contractor came back about three weeks ago and tried sanding it a second time (he said he was using a different type of sand and doing a few other things differently, but I don't know the details). The sand seemed to harden really well, but we had absolutely no rain for weeks, so we didn't get to really test out this new application until yesterday. It poured yesterday ... and we got a lot of wash-out. Maybe not as much as the first time, but we've still got a lot of loose sand all over the patio. I guess my next step will be to show him your suggestions and see what he thinks. He's being really good about working with us and trying to help us fix this mess, even though it wasn't his company that got us into it in the first place, so that alone has been a huge relief.

You mentioned that one of the root causes of our problem MAY be improper side restraint of the patio. When the patio was originally installed, they did not put in any edge restraint. We asked why not (after the fact) and they said "because it can pop up and look ugly." Quite frankly, I would much rather have an edge restraint popping up than this nightmare with the joints. Is there any way to install an edge restraint NOW, and would that perhaps help with the washout problem? I should mention that we have had almost NO noticeable shifting, buckling, or other movement of the patio in the three years since it's been installed, in spite of having no edge restraint. But the washout does seem worse at the edges.

And if it helps to know the exact type of pavers used, they are Belden Belcrest either 560 or 760 (not sure which). They're supposed to look kind of old and beat up (that's what I liked about them!) so a small amount of chipping isn't a big deal, I just get nervous about trying to powerwash a third time and wonder at what point they might just start falling apart.

Thanks again for all your help. This is a great resource as we try to solve this problem.

[teacher]

Well it sounds like you have a very responsible contractor, which is a good thing. I think it shows a lot that he is willing to work with you until the problem is fixed. To answer your question about edging, yes it can be installed after the patio has been installed. The contractor would simply need to remove the pavers around the perimeter of the project (this is commonly referred to as the soldier course), scrape away the bedding sand beneath those pavers, install the edge restraint directly on top of the compacted base material, and use 10" steel spikes to secure the edge restraint. Then he can go ahead and re-apply and screed sand, replace the pavers, and compact.

Some edge restraints do "pop up." This is caused by frost heave when the restraint does not have a lip that fits beneath the pavers. Edge restraints without this lip will move independently from the patio. Those with the lip will heave and settle at the same rate as the patio. Suggest to your contractor that he use one with a lip. Installing an edge restraint will minimize lateral movement in the systems and may keep your joints "tighter," which may minimize the amount of washout you are getting.

Keep us updated, and good luck!

[Derek]

Our company specializes exclusively in cleaning, sealing, and maintenance of segmental pavement systems, concrete of all types, and vertical masonry.

All the suggestions seem accurate. One of the big problems I encounter are contractors who do not properly apply joint stabilizing sand products, often not properly cleaning after sweeping and compacting, or more often, improper activation through too much water (or occasionally too little).

Even when properly applied, I see many problems with joint stabilizers in a freeze thaw climate. Often the poly sands AND the liquid stabilizers tend to adhere better to themselves and the sand than to the paver surfaces. When movement occurs during freeze thaw (it is flexible pavement) the sand tends to seperate from the pavers even if it remains solid in the joint. This allows weeds to take root (most weeds grow from the top down). As for the ants, they are VERY resourceful creatures and will eventually go through almost anything.

There are products for inhibiting weed growth and insect infestation (which appear to be your main concerns) that are readily available at the local hardware store. All the weed killer companies (Ortho, RoundUp, etc.) make an extended use weed preventer in liquid form. Most make relatively inexpensive products that will prevent weeds for 4 months...some as long as a year. So one spring application should last the entire season.
As for ants... I personally use Ortho Home Defense MAX at my house. I started using it as a preventative around the base of exterior doorways and the garage door. I began using it on my paver patio as well. Application is simple...just spray on the joints...enough to make them uniformly damp. Depending on the amount of precipitation, you may have to repeat the process every month or so.

I have never had any staining from any of the products I mentioned. I do recommend that before applying anything to your pavement, you should find an inconspicuous area (or some extra pavers) and test to be sure that there will be undesirable color changes or staining.

[mickiedaniels]

Hi bellea3! Have you tried Derek's opinion? It might be the solution you're looking for. Please share the results with us! Thanks in advance!

:)

[larful]

I hate Polymeric sand , I use it only sometimes on the job the main product I use is zero sand joint stabalizer. if I use Polymeric sand, to act as a weed barrier or if a customer requests it, or on this situation with a clay paver install job I did around a swimming pool We were forced to use the Polymeric sand stabalizer so the sand wouldnt stick to peoples feet and get into the pool. sweeping it out on moist clay pavers in northwest washington proved to be a difficult task. on a dry day even sweeping in the Polymeric sand still left a dry hazy sheen of glue on the clay pavers. which just balled up into mini glue balls after the sand was swept away. I think the clay pavers just held more moisture then regular hydro pressed pavers do. making the pavers cold to the touch and activating the Polymeric sand on contact very messy situation that eventually we got cleaned up without having to scrub the whole thing with acid cleaner. by just wet brooming it and letting time take its course we never got a call back nor did it look funky anymore after we left. I would honestly suggest trying a different brand of Polymeric sand . the Polymeric sand bags here run for around 38 dollars a bag, thats per pag price its spendy and I notice is very different in reaction from brand to brand. In the future if you want to avoid this and the customers are very perticular on weeds growing thru the pavers suggest a tighter new type paver that has smaller joints then the clay or old country style pavers. second you can do a 3/4 clear base and lay fabric then an inch of sand skreeted the weeds wont grow thru. as far as salvaging the job your currently working on try a different brand of sand where its a fine sand with the polymeric stabalizer.

<a href="http://s226.photobucket.com/albums/dd176/larful/?action=view&current=IMG00100.jpg" target="_blank"><img src="http://i226.photobucket.com/albums/dd176/larful/IMG00100.jpg" border="0" alt="Photobucket"></a>

[erwin.zeez]

Polymeric Sand Problems

There are relatively few problems associated with polymeric sand. The most common two we've found are below, as well as their remedies.
Cleaning / Removing Hardened Polymeric Sand From Paver Surface

Most often the need to clean polymeric sand from the surface of patio pavers or stone comes from not following instructions regarding applying or wetting the sand. Sand overflowing joints or piled in corners will quickly harden when wet, and spreading polymeric sand over pavers or stone while they are still wet (possibly from a recent rain) will activate the binder and harden the sand to the surface of the pavers. If the area where the sand has adhered to the tops of the pavers is small, a firm boot scrape may clean the pavers. If the area is larger or has had 24 hours to cure and set, scrub brushes should be used. We've also had members suggest using vinegar as a release agent on the pavers, and it seems to work rather well when combined with scrubbing.

[Tealeaf]

One of the things that I just found to my horror.
I used an older retained bag to re-do my back patio and needed a bit more to finish, so picked up another bag. the patio pavers are standard grey, the old product (same brand) was fine and there was no discoloration apart from the odd bit of sand overlay which I can deal with using the vinegar trick, I guess.

The problem is that the new bag has a blend that is more sand-like in its
coloration and this is not evident until you use it. A total disaster and I now have to re-mediate. The color on the bag is shown as Granite, but the retailer showed it in their system as Grey. If it is Grey then it is a muddy grey at best.
There is clear disconnect between reality and the system. Naturally, I was questioning it at purchase and have now initiated a complaint for resolution (here's hoping, but u know that hope is not bankable). No one in his right mind would use this new coloration anyway for grey patio stones as it changes the color completely.

Just another victim of the marketing process, I guess.
Of course, the manufacturer has a warranty limited to the cost of the product. My best bet is against the Retailer. If I get any positive result I will post it

[Tealeaf]

Further to my post, I had a meeting with the Techni-seal Sales manager and it seems that, yes, the product is now being made locally with a different sand content. I suspect also that the binder is a bit stronger.

Mea culpa, the install instructions have been made more complicated requiring the use of a compacter as well as a blower to blow off the residual sand.
Having used the product before, I used the new bag in the same way that I used the old bag, hence my poor result.

Techniseal will provide with a Remover in a week or so and I can use that 30 days after the Install.

Anyway, using this stuff for the average home-owner has become too complicated and involved and I won't bother again. Each to his own.
New Install Ok, but not retro.

Cheers and GLTA

[gcamry]

Tealeaf thanks for the heads up on that one. I am glad that you are getting a little satisfaction anyway. I am looking at doing a face lift on my patio so I am very thankful that I saw this before purchasing my products. Do you have recommendations for a retro/face lift?

Also, I am always looking for quality help for short term projects have any of you had luck or tried finding help by searching the web for something like San Francisco handyman, thanks for you help

[cynergy]

Hello. I'm kind of at a stand still right now on my waterscape. Yes I said waterscape and we are talking about polymeric sand. It soundes like a good idea in my head to fill in the cracks of the river (sandstone) of a 6,000 gallon pond. I do know that polymeric sand has to be wet down to dry and hard up. Here's the problem, homeowner turned on the pump after i left jobsite.. I returned to a mess. We have slime in the main pond. I pulled up all the sandstone in the river to remove what seems to be only sand without the polymeric. The water in the main pond has a layer of, what looks like, liquid nails on the top. Homeowner does want fish. does anyone know if there is something to counteract the polymeric in the water to save it? Or is my best bet to drain it?

[Tealeaf]

Hi G,
Actually, I still have no satisfaction on my Polymeric sand discoloration problem.
After a reminder, last I heard from the manufacturer rep was that they were coming by 2 weeks ago to fix the problem. No Show and even a further e-mail has received no response. Maybe he is on Holidays, but nevertheless!! All I have learned from all this is always to mix old and new products before use, but even then, I would have had discoloration.

I have concrete paving bricks as I am here in North Vancouver, BC. What kind do you have? I think the contractor fellow who commented on the sand was right to distrust the P sand product. I am reverting to play sand from now on in. The ants dislodge whatever you use anyway and using a compacter just for putting the sand in an older
install makes little sense unless you have serious uneven layers.

If it is not one thing it is another. I just tried Just Answer web-site for an answer on
a carport topping gone awry and that was a help. Just cost $15.

Good luck
Tealeaf

[Paver]

Hello. I'm kind of at a stand still right now on my waterscape. Yes I said waterscape and we are talking about polymeric sand. It soundes like a good idea in my head to fill in the cracks of the river (sandstone) of a 6,000 gallon pond. I do know that polymeric sand has to be wet down to dry and hard up. Here's the problem, homeowner turned on the pump after i left jobsite.. I returned to a mess. We have slime in the main pond. I pulled up all the sandstone in the river to remove what seems to be only sand without the polymeric. The water in the main pond has a layer of, what looks like, liquid nails on the top. Homeowner does want fish. does anyone know if there is something to counteract the polymeric in the water to save it? Or is my best bet to drain it?

Do you have some pictures you can post?