[PERRY]

I am a homeowner in central NJ. Two years ago we decided to rip out bushes and a small sidewalk and install a 20 by 25 foot patio. The landscaper took all summer to finish the job and he seemed to take great effort laying down sublayers and stamping everything very firm. However now what I am seing is in all spaces in between the pavers there is what looks like dirt (mud) Its only inbetween..its like this has taken the place of the sand that was originally there. In some places there is some moss growing. For further clarification this patio sits inbetween two additions...a sun room and an extra bedroom at the center of the back of the house. So its very private kind of tucked away inbetween the additions. The ground is all very much clay soil everywhere in the area. What is going on here and will this get worse and what is the solution? Thanks for the help! Perry.

[Adam Buckpitt]

Perry it would seem to me that your patio is probably not getting much sunlight to burn off any moisture that is getting on the pavers. There might not be enough pitch to the patio. You could use some sort of cleaner for your patio and see what that does. If the sand wasn't bound together somehow with a sealer or polymeric sand you may have had a little washout. If this is the case than you can pressure wash your patio with a wide fan nozzle and reinstall sand. The patio will be good as new. If the moss is due to lack of sun you will probably want to set up a cleaning and maintanence program.

[PERRY]

OK so this is something that can happen...somewhat common I hope! Actually the patio does get quite a bit of Sun. We have trees around but during most of the day it gets full sun. I would say full sun for most of the hottest parts of the day during summer. I lay out on that patio sunbathing during that time. I was thinking that perhaps the placement of the patio.....between the two large additions causes that patio area to act like a basin...catching rain and ground water and this all rises from below bringing with it the sludge. If I powerwash it what do I use to fill the gaps? I think the landscaper used just sand..is there something else that would be more permanent????

[Stonehenge]

It's likely not sludge from below - just airborn debris that gets snared by the seams in the pavers and settles there. If the sand between the joints is polymeric (it'll be hard if it is), pressure washing at a very shallow angle would probably be OK. If it's just a regular joint sand, you'll probably wash out some of the sand as well and need to sweep some in.

As for the moss itself - I always love the look of moss growing on a paver patio because it gives the patio such a look of venerability. I always get a little sad when I hear someone wants to remove it. But to each their own, I suppose.

I wouldn't be inclined to assume that the patio was improperly installed without being able to see it in person myself. Moss growing on patios is a common thing, even with patios where polymeric sand was used between the joints. It's usually a product of extra shade and the unburned moisture that the shade causes. Get a little organic material in there (blowing bits of dirt and dust, grass clippings, etc) and you have a great spot for moss.

I know you said you sunbathe on the patio, but even so, being between two structures I might still think it's the shade, unless your patio gets full southern exposure.

[PERRY]

The sun travels directly over the patio so it gets all the sun when the sun is at its highest in the sky. Im out there in the summer from say 10:30 to 4PM and have sun all during that time. OK so now I understand......dirt etc sticks in the cracks and thats where the moss grows. I was worried that the soil underneath the patio was rising up between the cracks and soon it would cover the entire patio!

[Adam Buckpitt]

If you pressure wash the patio and remove some of the sand you can go to a local supplier for pavers and they will typically have bagged joint sand that you can use. Unless you remove 2/3 of the joint sand I wouldn't use polymeric sand because it might pop out in winter. Ask your supplier about what they would recommend doing. There are many products out for sealing sand or cleaning. Stabilized sand will be easier to clean than regular joint sand.

[eastern1]

Sounds like you may have a dip in the patio and water remains after a storm. If this is what you are seeing, you may have to lift the brick in that area. What materials were used for the construction of the patio base, did he use limestone screenings or sand. We often see moss growing on the northern exposed walkways or patios etc. Do you still have warranty on the stone work?

[PERRY]

The landscaper took 6 months to finish the work over the course of the summer/early fall. I think I saw him use a sandy type material as well as gravel. Both of which he pounded down solid. Water does pool in areas during very heavy rain but will drain soon after. Where it drains to is a good question really. The ground is very heavily laden with clay soil. Its TIGHTLY packed clay soil. Just last summer I paid a guy to dig a dry well for me in the back yard to help drainage. i bought him a new pick ax. Within 10 minutes he showed me he had bent the ax because of the tightly packed soil. So as I said I dont know where the water goes once it drains through the pavers!

[scl]

Have you contacted your installer? Not trying to be corrosive or flippant, but give him a call and see if he would come look at it. In my installs, I will usually resand for a small fee if the customer would pressure wash. But thats me not him. Most guys are easy to work with.