[B.lock]

Anybody ever skip the screed process for bedding material?

I know a guy that mechanically installed his parking lot right over his compacted stone base. His asphalt experience on a 2-ton roller made it fairly easy to prepare base almost to perfection. He completely skipped the screed process.
All his finished grades are right on, yet I have to wonder how well it will preform longterm: without bedding material.

Just wondering if anyone has done this before?

[site]

If the rest of the prep was properly done it will last as long as anything with bedding material. It sounds like he did the compaction right.

[lasting impress]

I dont see how you can get the surface flat enough without using sand or stone dust (we use stone dust). When asphalt is done, the use 5/8 as their bedding. They dont asphalt over 2" minus. They get away with 5/8" minus, because as the paving machine is traveling over the imperfections it can fill them in with asphalt. That is the same idea as laying a bedding material.

Thats my 2 cents Canadian (which is worth about $5 US) lol.

[Orchard Ex]

I wonder if the base is really compacted enough. I looked at picking up small ride on roller for doing driveway bases too, but they typically don't have the compaction force necessary. A static roller (2 ton) would only have 1 ton of force under each roller, a double drum vibratory will usually about double the force but again that's only 2 tons across each roller. Not much more than a small plate compactor.

[mrusk]

The bedding sand has nothing to do with leveling the base!!!! The bedding sand is to give the pavers there 'interlocking'.

[Stonehenge]

I think ICPI specs allow it to be used for both, as they often give a +/- 3/8" range for the crushed stone portion of the base, relying on the sand to make up for any fudging in the crushed stone...

...Which is part of the reason (among many) that I don't like using sand unless a situation demands it.

[B.lock]

I agree with you Jeff... sand is the weak point of the system. It does funny things when it's wet. Kinda like David Copperfield-IT'LL DISAPPEAR!
But I'm just wondering if you, or anyone else, has done an installation without bedding material?

[mrusk]

Without sand you are not installing interlocking concrete pavers!!!!!

There is no interlock then!!!!

[B.lock]

The paver he installed is Optiloc. An L-shaped paver with great interlock. But even if it was hollandstone, whats bedding material got to do with interlock?
Granted, if he did surface compaction over sand and drove sand up 1/2" (and that's a stretch). You would fill the remainder with joint sand from the surface.
So what's the difference if the entire joint is filled from the surface?
The end result is the same!

Permeable pavers typically have great interlock without ANY fines.

[lasting impress]

Originally posted by mrusk
Without sand you are not installing interlocking concrete pavers!!!!!

There is no interlock then!!!!

Now youve got me confused???? Ive been using stone dust as my so called bedding material for 13yrs. In fact, I screed a hard base, no bars. You dont need a sand base for the pavers to interlock. Thats why you spread sand on the top and run your plate packer to force the sand into the pavers.

[mrusk]

There is no weak part of the interlocking concrete paver system. Its a system. All parts work together. If you leave one part out, you will have proablems.

Interlock has nothing to do with the pattern!!!! You run the compactor over the pavers before you sink sand into the joints
! Pavers will settle 3/8th of a inch. Then you sweep in your joint sand and compact more.

This is basic fundementals of pavers!! No wonder why so many paver jobs fail.

[Stonehenge]

Matt - I've been doing this for as long as you've been alive. And I've tested the various base prep methods side by side and posted the results.

Side note: pattern does affect interlock.

You are beyond your depth here, Matt. Your comments here expose that.

For those wondering, among the reasons ICPI promotes the use of sand bedding is for interlock, claiming that sand forced up into the paver joints better locks them to the base below and to each other. I do question the validity of better interlock when the sand comes into the joint from the bottom versus the top, but I could see an argument for it. That being said, the structural integrity lost by using a bedding sand course seems to outweigh any fractional improvements in interlock. My tests showed that.

[B.lock]

I've laid pavers over asphalt (neoprene tack coat), concrete (latex modified thinset, tube adhesives, dry grout mix[3 parts sand - 1 part portland]), over high density foam, on pedestals, over 3/8" chips, over screenings, over sand ... and one time I tried to put em over my ex-wife.

My point is that the base offers your support. Not your bedding material. Bedding material only offers a forgiving element in order to achieve a set, level paver surface.

BTW... the ex-wife patio didn't turn out too well.

[AZTLANLC]

Originally posted by Stonehenge
Matt - I've been doing this for as long as you've been alive. And I've tested the various base prep methods side by side and posted the results.

Side note: pattern does affect interlock.

You are beyond your depth here, Matt. Your comments here expose that.

For those wondering, among the reasons ICPI promotes the use of sand bedding is for interlock, claiming that sand forced up into the paver joints better locks them to the base below and to each other. I do question the validity of better interlock when the sand comes into the joint from the bottom versus the top, but I could see an argument for it. That being said, the structural integrity lost by using a bedding sand course seems to outweigh any fractional improvements in interlock. My tests showed that.

I agree 100% with this comments specially the one for Matt.

I also don't believe interlocking can't be accomplished without the use of sand unless sand becomes hard as a rock after goes into the joints from the bottom I'd think differently.

I have seen many many jobs where contractor used stone dust, mason sand and other materials not recommend it by ICPI and many of them still look real good, the ones that failed the reasons were not the use of those material.
Most commons failures I have seen are due to little or no base material, no edging or not proper edging material, not proper pitch on surface, too much bedding material.

At one of the seminars I attended this season put up by a paver manufacture the speaker when on to say that stone dust is a no no due to the sharp particles in it, they had a drawing showing that this sharp edges would crack the pavers when you compact them, unless those pavers are garbage that might happen I know that because we use 1/4" inch gravel for our bedding sand and the only time we broke a paver there were a 3/4" stone under.

[Paul]

I'm going to weigh in on this, other than a few notable people here, I've probably installed more pavers than most and repaired more pavers than most have installed new. the number one reason for paver failure is poor base and sub base construction! I've seen it all sand, no sand, screenings, stone dust, ect.......

If the sub base isn't right, incomplete compaction, poor soils, wrong type of equipment used to compact sub base, it's going to fail. Same with your base if you think a 3000 lb plate is going to get your base compacted to 95% proctor you have another thing coming. Big plates, vibratory rollers, Sheep footed rollers are all things that you need access to in order to install pavers correctly.

I'll get a lot of flack from some here but a poorly constructed sub base followed by a half ass base is the largest single failure point followed by poor edge restraint (which is also subject to your base prep) is number 2.

We had a 9 ton roller, a 72" plate for our skid steer, a 66" roller for our skid steer and a 9000 lb plate just for base prep. We rented sheep foot rollers (a real telling sign when you start running one of them over a new construction site!) Next time you think you have a great sub base try this, drive a 12" spike into the sub base, if it goes in without a lot of fight your sub base is not ready. Next try the same thing on your base if you can drive it in with a light 2 lb hammer and only a few hits it's not tight enough. we used palm air nailer and Bosch electric hammers to drive our spikes. Watching one man walk around the job site with a 15 lb Bosch roto hammer and a take a half hour to install a 50 lb box of nails is a telling sign that you got it right, he will bend a few too!