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Pervious concrete driveway

LudwigHW's picture

I live in west-central Oregon on the sand dunes.  I have a large driveway that needs replacement; it’s about 2,500 sf.  Several neighbors have advised using pervious concrete because of drainage concerns.  The pervious concrete would also reduce some issues with sloping the various parts to a common drain.  I’ve seen some pervious concrete in town and am satisfied with the different look.

I have a concrete contractor that’s well respected in my town and they are bringing in an excavation company to remove the existing concrete, several old tree stumps, and two trees.

Both contractors advise against pervious concrete.   They say, it’s more difficult to install, is about 30% more expensive, and in our environment – the sand dunes next to the ocean – the concrete “pours” get clogged with sand, pine needles and sap.  They both say that I will be sweeping and power washing the concrete “all the time.” I don’t think they’re trying to deceive me, but I’m a city Planning Commissioner and I would like to set an example for changes we’re asking other property owners to make.

Are these issues great enough to weight against using the pervious concrete?

Your contractors are probably (post #203516, reply #1 of 22)

Your contractors are probably being optimistic. Sweeping isn't enough, it will probably need to be vaccumed as well as pressure cleaned or the pores clog and all you're left with is an expensive, ugly driveway that is weaker than standard concrete.

Florida Licensed Building Contractor, 40 years experience in commercial remodeling, new homes, home remodeling and repairs and all types building maintenance.

How are the neighbors' (post #203516, reply #2 of 22)

How are the neighbors' driveways holding up?


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

driveway (post #203516, reply #3 of 22)

Might consider using pavers. Would function similarily. Don't know about you sandy soil/base

what are "drive on" pavers (post #203516, reply #13 of 22)

what are "drive on" pavers called- most paver articles seem to be for walkways.

if I wanted to park a boat on pavers what type pavers would i use?

Pavers (post #203516, reply #14 of 22)

I'd suggest concrete paver bricks. They are more than strong enough but your base will need serious preparation and compaction. There is a local mall parking lot in these and they have stood up very well for a few years now. No sign of breakage or ruts. And that is in an area with poor soils that required serious preloading for the building areas.

(The sand in your pervious concrete driveway will get thoroughly compacted by your car tires and will be very slow draining.)

John

Put it in. (post #203516, reply #4 of 22)

Then if it fails you can argue against it being a viable option to the rest of the commision. 

Talk to the batch plant (post #203516, reply #5 of 22)

that supplies the material, and ask for references to other owners that have installed it. Call them and find out how it's performing.

I noticed a lot of this material at the Seattle Zoo last time there. I think it's a refreshing change from the look of typical flatwork.... nice and coarse-looking. 

The real story (post #203516, reply #6 of 22)

Ludwig,

With all due respect to the contractor you mentioned as well as some of  the folks who commented it is clear they have little actual knowledge of, and no actual experience with, pervious concrete. I am the owner and president of Bay Area Pervious Concrete in northern CA and have spent the last five years installing, testing, doing/reading reseach on pervious concrete.

I have a little experiment I suggest you perform. Take a pitcher of water and head out to the beach or nearest sandy area, pour the water on the sand and observe what happens. Did the water puddle and just sit on top, or did it simply go right thru the sand? Well we already know what will happen; the water will go right through of course. Why, becasue sand is completly pervious.

So now imagine your pervious concrete driveway covered in windblown sand, what happens when the rain falls on it?  Yes, it will go right thru the sand and then make it's way through the pervious concrete.Tell me something, if your regular concrete driveway was covered in sand and pine needles would you ever bother to sweep it or blow it?  Sure you would. If you did no more than that you would be fine. 

Bottom line is that if the pervious is installed properly by an experienced contractor who truly understands the product you will get outstanding performance for many many years. My guess is your contractor is not well versed and his comfort level with the product is low, hence the high price and low expectations. Asking for a reference from the concrete supplier, as someone suggested, is a good place to start.


As a city planner you are no doubt aware of the issues and challenges surrounding storm water management and the need to move toward more low impact development in our communities. I would be happy to discuss the subject in more detail with you should you desire. Just head over to my website and drop me a note on the contact page.

David

David - very nice responce to (post #203516, reply #7 of 22)

David - very nice responce to a question relating to a product you market.  I would suggest adding a link to your company in your signature line as well.

YAY!  I love WYSISYG editing!  And Spellcheck!

____________________________________________________

Now let's fill a 4 inch sewer (post #203516, reply #9 of 22)

Now let's fill a 4 inch sewer pipe with sand and flush a few toilets. What, your toilets are backing up? How can that be since it's just sand?

Obviously sand on a beach is one thing, sand in a pipe is another and sand on a pervious driveway is still another. We all know, most from experience, that sand WILL clog a 4 inch pipe or a water heater drain or your weeping tile and it will certainly clog pervious concrete. Technically I suppose you could argue that moisture will get past the sand in all those situations but practically there is no water flow so effectively they are all clogged. Also in damp, rainly climates pervious concrete grows mold and algae like an overrun garden and both will  grow over the concrete and slow or totally prevent water penetration.

Florida Licensed Building Contractor, 40 years experience in commercial remodeling, new homes, home remodeling and repairs and all types building maintenance.

Now make that sewer pipe with (post #203516, reply #10 of 22)

Now make that sewer pipe with a cross section as large as a driveway, and make the sand clogging it only, say, 1/8" thick.  How much water will get through?


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

Where is there a driveway (post #203516, reply #11 of 22)

Where is there a driveway like that? In the real world sand drifts onto a driveway a little at a time. It fills the pores from the bottom up until the entire cavity is packed full to the depth of the concrete. No water flows through at all, just like a sewer pipe.  Yes, a slight amount of water will penetrate the sand but most will run off the edges of the slab, just like regular concrete. Don't take my word for it though, fill a 4" piece of soda straw with sand then pour water over it and watch the water pour over the edge.

Florida Licensed Building Contractor, 40 years experience in commercial remodeling, new homes, home remodeling and repairs and all types building maintenance.

But make the soda straw have (post #203516, reply #12 of 22)

But make the soda straw have the cross-sectional area of a driveway.  How much water will get through?


Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

I’m a city Planning (post #203516, reply #8 of 22)

I’m a city Planning Commissioner ..

aha, now I understand the question..........<G>