[Bob]

Looking for information on installing pavers. How to figure out sub-base/stonedust/sand? All information will greatly be appreciated. example, If driveway is 10 by 40 how would I figure out how much material are needed..

[Stonehenge]

Welcome aboard Bob!

There are quite a few quality hardscapers here, so you should get some good info for your question.

For a typical patio or walkway installation, I use about 3 tons of crushed stone for every 100 sqft of paver area (a bit more for walkways than patios). For driveways, add about 50% to that number (4.5 ton per 100 sqft). I like to excavate to a depth of 12" for driveways (more if the soil is unstable at the 12" depth). Of that 12", almost 10" will consist of stone, the other 2" (plus a little) is the pavers, depending on the pavers you use.

I like to use 3/4"- for the largest part of the base for driveways, the last inch or so I use screenings (others here will recommend a coarse bedding sand). We install the stone in lifts of 2-3", compacting each time. I also like to use a geotextile beneath the base for driveways, and we sometimes even use layers of geogrid between lifts of stone.

Prep so there is a crown in the middle of the drive, and specifically for a driveway, try to make sure you don't have any tiny sliver cuts, as they tend to crumble under the weight of a vehicle.

I'll step aside and let our other members give your their input as well. Listen to all, make your own decision.

One quick question - what level of paver install experience do you have? It might help so we can know what detail we need to go into.

Good luck!

Jeff

[Paul]

Hi Bob, Welcome to GTX. I try to use tonnage for my base and sand. For pavers I'll use Sq footage. So you have a 400 sq ft area, not knowing what your soils are like I'll use a .8 multiplier for the base this will give you about 10" of base material so using a general figure 400 X .8 = 320 Cu ft, now multiply that by 150 (lbs per cu. ft.) and divide by 2000 you get 24 tons. Now that 150 is a guess for your area, add or subtract for the weight of base material in your area. Sand for your bedding course, I use 10 lbs per sq. ft. So figure you need 2 tons for that drive, I add 10% as my fudge factor. If the drive was straight and the pavers used were a simple pattern, I might just add in 5% overage for my cuts. Edging and nails, I figure by the lin. ft. One foot of edging needs one nail, so your 40' drive you need 80' of edging and 80 nails.

These are some quick numbers that will get you in the ball park, you might need more depending on soil conditions and paver type.

[Carlita]

Hi Bob,

I think you are going to find that we all have different formulas in figuring our materials, but you will get the same results.

You had mentioned that the driveway is 10 by 40. We would dig the area an additional 12" on the sides which you will be placing your cement/plastic edge restraint.

Good Luck

[Stonehenge]

Carlita - is everyone still using slag sand in your neck of the woods? That was the only way it was done, say a dozen years ago or so (pedestrian paver pavements, that is)...wondering if that's still the case.

[Carlita]

I know you call still find some company's in our area who use slag sand for their base and that is it. But we only use it for the last inch or two.

We install our base as follows:

Pedestrian : 5" - 21AA Crushed Concrete
1" - Slag Sand

Vehicular: 9" - 21AA Crushed Concrete
1" - Slag Sand
* And we also use a geotextile fabric under the 21AA.

We tend to follow ICPI guidelines with the exception of the use of slag sand. They recommend the use of 2NS. But we like to use the Slag because it compacts.

[Stonehenge]

When I moved to Wisconsin I asked around, and nobody had even heard of slag sand. After I did a little checking, I saw that slag sand can contain lead and cadmium, and that I should have been checking for the levels of those in the slag sand, by asking the supplier for their periodical EPA reports, or something to that effect. Do you know if anyone does that checking now?

[Carlita]

Not to my knowledge.

The only problem I have had was some unique specifications for a large commercial application. The specs called for slag sand only if we removed all fines passing the #100 sieve by screening and washing. Needless to say the cost to do this was 3 times the standard material cost.

This job was 160,000 Square Feet of pavers on top of a roof deck. They were concerned with the slag causing damage to the waterproofing.

I tend to see more and more architects who just think too much, and need to let the experts just do our jobs.

FYI: We were awarded the job and had the standard slag sand approved!

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On another note.

Do you see alot of commercial jobs spec'd with pavers on a bituminous setting bed ?