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View Full Version : Permeable Pavers? Really???


JimLewis
09-08-2011, 07:29 PM
I just wanted to start a conversation about "permeable" pavers. I put quotes around that phrase because I sort of question really how permeable they really are. I'd love to see some numbers on that.

Regardless, I almost never get a request for these. Every once in a while (1 out of 20 calls) I will get someone ask me about them. But then as we get into discussing the advantages and disadvantages, they always end up talking themselves out of it. Then we end up building them a regular paver patio.

It seems like one of those things that the "industry" thinks is really hot, but - at least in the residential market - isn't really hot afterall.

First off, I've never seen one that looked all that impressive. The few that I have seen look a little too 'commercial' and not very attractive. When I see one, I am usually thinking to myself, "Hmmm... Permeable pavers.... Well, that's interesting." I never say to myself, "Wow! That patio looks sharp!" So I a hesitant to get into doing them just for that reason alone.

I also hesitate because I read somewhere that they really aren't that permeable. It was in one of my trade journals, I think. But I can't remember which one or when I read that. So I wonder really how permeable these things really are. Are they 75% gimmick and only 25% really helpful?

Another hesitation is the gravel that has to go in the joints. My experience with wider joints and having gravel in them (the few times we've done that with flagstone) is that the gravel is constantly coming out of the joints and creating a mess. Also creates more maintenance as you have to replenish the gravel or sand more frequently, I would think.

Anyway, they're not that popular with residentials so far - at least not yet. But I do see a little bit more interest in them these days. Got a call today for one. Just not sure I want to go down that road. I'm pretty happy just using the pavers we use now. They always turn out great and very little maintenance and our customers love them.

I'd love to hear your opinions, see any studies or articles you guys can point me to regarding how permeable they really are, see some photos of ones you've done, hear about what kind of interest you're getting from residential clients in your area, etc.

.

AztlanLC
09-08-2011, 08:10 PM
they work pretty good in my opinion, I have talked to couple contractors that live in certains parts of the the country where people want to install a pool or patio but due to restrictions they can't use any surface that would increase run off using permeable pavers they get around that, also I have heard many areas are starting to implement requirements for new commercial sites where a certain percentage of parking area has to be permeable.
My only experience with permeable is a small section in front of my driveway that I used them due that I was getting water in the garage and they do work pretty good they can take a pretty good amount of water.
you will get minimal stones in the surface compare to flagstone or cobble stones.
Techo-bloc, cambridge, and unilock have some nice looking permeable pavers.
I think in a residential application I would only use them for a special purpose.

SDLandscapes VT
09-08-2011, 08:21 PM
Jim

The University of Minnesota Landscape Arboretum constructed a test display to show the effectiveness. This isnt the best link, but best I could do fast--

http://www.arboretum.umn.edu/UserFiles/File/Runoff%20Model%20Outreach.pdf

Very industrial looking but functional. I think for residential unless they were planning on doing the driveway the benefits would not be large enough to justify the extra cost and extra maintenance.

my .02

TomG
09-08-2011, 09:12 PM
We do three or four permeable paver jobs a year, mostly residential, mostly at houses on lakes. We had one job this year that a homeowner (on a lake) was waiting for a permit for 3 months for a small 200sf patio. They got sick of waiting and asked us what they could do, we suggested permeable, we re-did the design and it was approved in one week! PICP's are still not that common in my area but they are definitely catching on, we have done more and more each year in recent years. Remember PICP's are still very new.

PICP's can handle ALOT of water, yes if you look at just the percentage of area that is permeable (the joints) not a large portion of the overall area is permeable. I was at a class for PICP's and they had an area that was permeable pavers and they took two 50gal drums of water and dumped them out over the pavers at the same time and the water didn't go more than 15 ft. I was extremely impressed. I wish I had it on video...

PICP's in my opinion will be HUGE in a few years, especially because everything is going "green". PICP's have no runoff, and they can deposit the water directly below where the rain falls. They have so many uses, you can put a rubber liner in them and collect rain water to water your lawn, or use it as a retention pond at a big box store. Just think if wal-mart can make 100 extra parking spaces because they don't have to build that big ugly retention pond will they do it? Yes. Or if a builder in a new development makes a new road out of permeable pavers or even just a section and can eliminate making a retention pond, therefor saving a build-able lot or two, would they do it? Yes.

The problem is not a lot of people even know what a PICP is including town engineers. Installation of a PICP is WAY different than a normal paver application and a lot of contractors don't realize that so they install them wrong and PICP's intern get a bad wrap. The company I work for has helped a lot of towns near us design PICP test sties so the town can do research on PICP's so we also get a lot of calls from towns and homeowners saying "why is my PICP not working? can you come out and look at it." I have been out to sites where the PICP was placed on the normal 3/4" base or the contractor used poly sand in the joints...:hammerhead:

I would HIGHLY recommend to everyone going out and getting PICP certified (my father an I both are). We are noticing more and more towns and commercial projects requiring the installer to be PICP certified. I believe ... not 100%... that my father and I are the only PICP certified contractors in our state. So that means we get all the calls. Also don't quote me on this either but I believe there are less than 200 certified individuals in the US.

Bottom line is, PICP's are going to be a huge part of the paver industry in the coming years. People just need to get educated about them.(Mostly engineers and town engineers)

Also paver companies are constantly coming out with new PICP's that look good. Also remember you can make ANY regular paver permeable, just by adding some plastic spacers in between the pavers. (Yea its a pain)
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Here are some pictures of a few projects we have done...

First 2 pictures are of a patio we did on a lake.

Second 2 are of a driveway we did, client had a problem of the water running off the street down his driveway and into his house, since our installation about 5 years ago he has not had one problem.

Last picture, this was done with plastic spacers. Its in a completely inclosed court yard in the middle of the high school i went to. They had no area for run off so we did permeable.

TomG
09-08-2011, 09:17 PM
Here are some pictures from the college I went to (University of New Hampshire). UNH is one of the countries leading researchers in all types of permeable pavements. They recently did this large parking area in conjunction with ICPI and a lot of other research groups. We didn't do the original install, but we helped with the design and a few weeks ago we went and re-infilled the joints with 3/8" stone. Not exactly sure the square footage but its a lot.

jonesy5149
09-08-2011, 09:22 PM
The down fall of these pavers (my .02 cense) is we do lots of work for Engineers and the little one we did for stair bucks three weeks ago we had to dig down 4' (to get the geo thermal of the earth) (crazy idea) then pipe it to a tank that held 400 gallons then into the drain in the road. Thanks walmart

big daddy b
09-08-2011, 09:52 PM
We've done a couple permeable paver patios so far this year, also lake houses, they worked out really good.
As far as the above mentioned for the stone falling out of the joints, there is a glue that we put specifically designed for that application and again it worked out great, but was a huge pain in the ass applying and not getting any on the pavers.

TomG
09-08-2011, 10:07 PM
We've done a couple permeable paver patios so far this year, also lake houses, they worked out really good.
As far as the above mentioned for the stone falling out of the joints, there is a glue that we put specifically designed for that application and again it worked out great, but was a huge pain in the ass applying and not getting any on the pavers.

Well I'm intrigued, what was the glue? I would think any sort of glue would reduce the permeability of the joint stone?

STL Ponds and Waterfalls
09-09-2011, 07:04 PM
We did a parking lot in '08 and they are holding up great. It's kind of cool to watch the water flow into the area's and flow right into the joints with ease. We use 3/8 granite chips and they lock in good. At first they are a little bit of a pain maintenance wise. All new construction or rebuilds in some area's of my state have to have a percentage of permeables.

The thing I like about the PICP's is buiding them in the winter time. No frozen minus or sand to thaw, your biggest challange maybe the frozen soil on excavating, but you usually have to go past the frost line in these pits anyway. You also save a little time on base prep using all clean stone vs minus/crushed base.

big daddy b
09-09-2011, 10:37 PM
Well I'm intrigued, what was the glue? I would think any sort of glue would reduce the permeability of the joint stone?

http://celltekdirect.com/glok.html

it's called gravel lok. Like I said it worked awesome, just really bad if you get it on your hands, clothes, pavers, trucks...basically just about anything that isn't stone. It was still very permeable and gives the stone a little bit of a shine when first applied, but wears off after a little bit.

TomG
09-09-2011, 11:17 PM
http://celltekdirect.com/glok.html

it's called gravel lok. Like I said it worked awesome, just really bad if you get it on your hands, clothes, pavers, trucks...basically just about anything that isn't stone. It was still very permeable and gives the stone a little bit of a shine when first applied, but wears off after a little bit.

Very cool, I have never seen that before. Thanks for the link and info!

DVS Hardscaper
09-09-2011, 11:35 PM
I'm a little leary of the job that Tom showed of the basement level patio. They're dumping water into the ground right along their client's dwelling's foundation. I always *thought* the name of the game is to sheet/get water AWAY from the dwelling / structure.

DVS Hardscaper
09-09-2011, 11:52 PM
Getting back to Jim's stuff.

I truely believe permeable pavers have more of a use in commercial / industrial applications. The pic Tom showed of the Univeristy with permeable pavers is a realistic scenerio as well.

In the residential world in the DC area most of the folks interested in permeable pavers are your GREEN freaks / Tree Huggers whom drive those Toyota Yaris things.

They call for estimates. Are all gung-ho about getting their permeable pavers.......until they hear the price!!! Alotta excavation. And you have to haul the spoils away to dispose of, this gets pricey. And all the gravel adds up.


Maintenance:
One fact is sediment. Sediment is a part of our lives. You go clean your roof gutters on your house and you'll find sediment in your gutters from the pebbles in your roofing shingles and from trees around your house.

A parking lot and road ways always have sediment.

About 11 yrs ago We used to mow storm water management retention ponds. We had one contract for about 7 years. And over the course of time I watched one pond accumulate sediment. It's a fact that storm water retention ponds WILL need the sediment scrapped up about every 15-20 years. There are companies that do nothing but clean up SWM ponds.

ok, I'm asking this based on my own observations - what happens with the permeable pavement after 15-20 years and all that aggregate is compacted with sediment??? Wouldn't it be less intrusive to mother earth to clean sediment off of a 1 acre SWM pond than to take up 12 acres of permeable parking lot and redo?

It's like the tree huggers that say "don't burn brush piles, the smoke is pollution. So instead chip/grind the brush and use it as mulch". Ok, well - the chipper or grinder creates even worse pollution. So whats the difference?



,

TomG
09-10-2011, 12:06 AM
I'm a little leary of the job that Tom showed of the basement level patio. They're dumping water into the ground right along their client's dwelling's foundation. I always *thought* the name of the game is to sheet/get water AWAY from the dwelling / structure.

Ahhhh see... this is exactly why people need to get educated on PICP's. As I said before they are way different to install than a normal paver application.

First off this area doesn't see much water because of the deck over it, but lets just make that a mute point for the sake of this conversation. Water does pitch away from the house you just can't see it from the picture because it is happening under the patio. The sub base is pitching away from the house and then there is a french drain exiting one end of the patio (also underground) to carry the water away. And if you were really concerned with water you could still pitch the sub-base but add a nonporous rubber liner. The patio is permeable because of permitting reasons because it is on a lake.

There are so many options with PICP's, if you wanted you could wrap the whole PICP base with a rubber liner pitch it to a water holding cell, throw a pump in it and water your lawn. PICP's are the future!

TomG
09-10-2011, 12:18 AM
Maintenance:
One fact is sediment. Sediment is a part of our lives. You go clean your roof gutters on your house and you'll find sediment in your gutters from the pebbles in your roofing shingles and from trees around your house.

A parking lot and road ways always have sediment.

About 11 yrs ago We used to mow storm water management retention ponds. We had one contract for about 7 years. And over the course of time I watched one pond accumulate sediment. It's a fact that storm water retention ponds WILL need the sediment scrapped up about every 15-20 years. There are companies that do nothing but clean up SWM ponds.

ok, I'm asking this based on my own observations - what happens with the permeable pavement after 15-20 years and all that aggregate is compacted with sediment??? Wouldn't it be less intrusive to mother earth to clean sediment off of a 1 acre SWM pond than to take up 12 acres of permeable parking lot and redo?

It's like the tree huggers that say "don't burn brush piles, the smoke is pollution. So instead chip/grind the brush and use it as mulch". Ok, well - the chipper or grinder creates even worse pollution. So whats the difference?



,

Maintenance is definitely a big key to the system working especially for commercial, not as much residential. For areas that get a lot of sediment they should be gone over with a vacuum truck at least once a year. The truck will suck out the stone in the joints but not the pavers, the truck then dumps out the stone it gets washed and then re-applied back into the joints, or just new stone is used. I have seen this process performed and it really doesn't take that long. When we re-infilled the joints at the UNH job (the one that I posted pictures of) it took 4 guys half a day to do and it was a good sized area. If its really big just use a skid steer with an angle broom.

JoeyDipetro
09-10-2011, 12:59 AM
I hear ya Jim on the industry folks hyping picp. We see it more and more in residential applications due to impervious coverage limitations.

Tom, I always enjoy looking at your pics and look forward to your very informative posts. Thanks!

DVS Hardscaper
09-10-2011, 01:31 AM
Ahhhh see... this is exactly why people need to get educated on PICP's. As I said before they are way different to install than a normal paver application.

First off this area doesn't see much water because of the deck over it, but lets just make that a mute point for the sake of this conversation. Water does pitch away from the house you just can't see it from the picture because it is happening under the patio. The sub base is pitching away from the house and then there is a french drain exiting one end of the patio (also underground) to carry the water away. And if you were really concerned with water you could still pitch the sub-base but add a nonporous rubber liner. The patio is permeable because of permitting reasons because it is on a lake.

There are so many options with PICP's, if you wanted you could wrap the whole PICP base with a rubber liner pitch it to a water holding cell, throw a pump in it and water your lawn. PICP's are the future!



Well, I'm pretty well educated on permeable pavers.

In terms of the aforementioned picture, seems to me that what you just described defeats the purpose of permeable pavers. And kinda cancels out the client's financial investment.

Ok, then why not just do a typical paver install, with the typical pitch, with a drain "to carry the water away"? The water still ends up at the same place. Whether it's a drywell or a collection tank for re-using the water. For 1/2 the cost.




,

DVS Hardscaper
09-10-2011, 01:44 AM
Maintenance is definitely a big key to the system working especially for commercial, not as much residential. For areas that get a lot of sediment they should be gone over with a vacuum truck at least once a year. The truck will suck out the stone in the joints but not the pavers, the truck then dumps out the stone it gets washed and then re-applied back into the joints, or just new stone is used. I have seen this process performed and it really doesn't take that long. When we re-infilled the joints at the UNH job (the one that I posted pictures of) it took 4 guys half a day to do and it was a good sized area. If its really big just use a skid steer with an angle broom.

I think we have been to the same class(es).

And I didn't buy the vacuum truck routine then.

Sediment accumulates faster then most realize. And it's so fine it finds it's way to the bottom like sugar in a gum ball machine.


.

TomG
09-10-2011, 10:34 AM
Well, I'm pretty well educated on permeable pavers.

In terms of the aforementioned picture, seems to me that what you just described defeats the purpose of permeable pavers. And kinda cancels out the client's financial investment.

Ok, then why not just do a typical paver install, with the typical pitch, with a drain "to carry the water away"? The water still ends up at the same place. Whether it's a drywell or a collection tank for re-using the water. For 1/2 the cost.




,


HOW did I know...

The purpose was to have a paito in this location. If we did a typical paver install the property would have gone over its impervious cover restrictions. So its totally worth the investment because it was do permeable or do nothing... So the only solution was a permeable application. (Decks didn't count as impervious cover in this town)

Its all about impervious coverage and controlling runoff, permeable pavers have no runoff, even if you slope the sub base some water still goes strait down.

TomG
09-10-2011, 10:36 AM
I think we have been to the same class(es).

And I didn't buy the vacuum truck routine then.

Sediment accumulates faster then most realize. And it's so fine it finds it's way to the bottom like sugar in a gum ball machine.


.

Where did you take the class if you don't mind me asking.

And about the vacuuming, PICP's are still very new and that is why they are building test sites like the one I pictured. We shall see...

STL Ponds and Waterfalls
09-10-2011, 12:27 PM
Some area's here if you build a pool in the back and pour a concrete deck or plain concrete patio you will have to put in a permeable driveway, or vise versa. That's good for the contractor but a pain for the homeowners.

robcee
09-15-2011, 01:26 PM
http://celltekdirect.com/glok.html

it's called gravel lok. Like I said it worked awesome,

Hey, do you have any pics of your Gravel-Lok jobs? If so send to robcee@celltekdirect.com

We would love to check em out and possibly feature in our galleries