View Full Version : Who uses just stone for paver sub base?
05-07-2006, 10:05 AM
Ive always been using a varying depth of crushed stone, cr6 for all of our paver sub base installs. Topped with about an inch of sand for leveling purposes.
There is a very successful company locally who I found out uses a #7 stone and thats it for a sub base. He still uses the sand to sweep in and lock the stones when everything is complete. Ive seen some of his work and it appears to be high quality. Not sure what the long term effects are though.
Just wondering if there are many others using this method and how has it faired with you?
Im going to install a walkway at my house in the next few weeks (if I can find the time) and I think Ill try it using the #7 stone and no sand. I hear it provides good drainage, and is easy to work with and level.
wurkn with amish
05-07-2006, 06:42 PM
the downfall of using only #7's would be it doesnt compact as tight as your cr6. For retaining walls I throw about 1/2in of #7's on top of our 411base to help with leveling. I would continue to do as you are, unless the reps for the different companies suggest otherwise.
05-07-2006, 07:04 PM
What is #7 stone?
05-08-2006, 06:44 PM
I personally am not sure using #7 stone along with concrete sand is a good idea. The problem is the sand "should" eventually wash through the #7 gravel. Yes, the #7 gravel does provide good drainage, but a #7 or #8 gravel is usually used as the setting bed of a permeable paver base of #57 stone. Typically, a permeable paver base may consist of 2" gravel which is choked down with #57 stone with is choke down with #8 setting bed.
Just my thoughts. If you want to use the #7's, I'd probably consider using a filter fabric between the concrete sand and the #7 gravel..... Hope this helps.
05-08-2006, 11:23 PM
When they start making highway bases with #7 aggregate, then I'll be a believer in it. But around here - that ain't happening. Although I'm not sure what "#7" is. Is #7 what the same as the MD code #57's, which is used for 3/4-inch gravel? Different regions have different codes for the aggregates. When typinn on the www its best to refer to aggregate by size, so we all can know what you're talking about!
Pavement bases are comprised of 'Crusher Run'. Which is what is used for creating the base for highways.
You need a base that has smaller aggregates along with fines, which is what crusher run is. They are what fill in the *voids* and push out the air molecules. Air molecules open the chances of settlement. The objective is to close them off. Which is why crusher run is used and compacted.
Aggregate that is all the same size, without fines will give you the gum ball effect, even if the composition is angular. (before someone chimes in with "retaining walls use 3/4" aggregate...", let me say thats a whole different game.)
In this world many industries have successful companies doing things certain ways. That does NOT mean they are doing it correctly.
Its easy to get away with performing sub-par practices, as the average residential client hasn't a clue as to the proper way an interlocking pavement is constructed.
05-15-2006, 05:16 PM
if you compact it enough, its even more solid than process.
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