| Had 2 cement contractor give me quotes for a sidewalk. 1 contractor reccomends no sand base, just scrape it out, form, and pour. He said that the sand just gives a place for the water to collect and freeze and heave. The other contractor reccomended a 4″ compacted sand base and 4″ pour. I am here in Michigan and the area is in a clay soil. Which way should I go???? |
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lemme see... and the clay won't , huh ?
the compacted base is superior to the clay base..
a compacted gravel base would be superior to the sand base...
a compacted stone base over a filter fabric would be the best
Mike Smith Rhode Island : Design / Build / Repair / Restore
What's the difference between stone and gravel?
gravel has sand and stone in it..
most common type is "bank-run gravel"....IE: just the way it comes out of the bank
edit: "processed gravel" will have been screened to take the larger stones out, and usually some clay or clay and subsoil will be mixed in to help it bind
stone is stone...just stone.. usually screened so it is uniform in size.. like "pea-stone (3/8")... or 3/4" stone..
also stone can be crushed or natural.. if it is crushed and screened it is angular..
but if it comes out of a gravel bank, and then it is screened it will be round like river rock..
most people when they say gravel, they mean stone, but they are wrong,
ain't it a shame ?
Mike Smith Rhode Island : Design / Build / Repair / Restore
Edited 7/21/2004 10:12 pm ET by Mike Smith
>> most people when they say gravel, they mean stone, but they are wrong
I always thought when most people say a word means a particular thing then that's what it means. Who decides what stone and gravel mean, if it's not common usage? And whoever it is, why should I respect their authority more than common usage?
"most" people say cement when they mean concrete.
does that make them correct in what they are asking for?
Amen; I was going to bring up that very thing!
I suspect that just because the majority rules, they think that they are right, or wright, or maybe just write. When does a 2 x4 become a stud? Why can sheetrock be wallboard? Etc. Etc There are way to many people taking liberties with descriptive terms that lead to the many breakdowns in communication. You know what I mean? No, if I am lucky, I know what you said, the meaning probably won't be clear until somebody makes a wrong assumption and everyone is ticked off and threatening legal action.
I for one thank you Mike for taking the time to set us straight. I knew that there was differences, but I never remember what they are. Maybe this time
Dan
>> does that make them correct in what they are asking for?
To the extent that it doesn't actually impede understanding, yes. You could construct scenarios where the difference is crucial, but I don't think many of them are plausible. If I call the ready mix plant and order <n> yards of cement, I can be fairly sure that the range of possible end results does not include a guy showing up with a hopper trailer to pour <n> yeards of dry portland cement powder into my foundation forms. If nothing else, the price quote should alert me that there's some kind of discrepancy.
I admit a guy going into a big box store and asking for cement when he really needs something with sand and gravel in it may be in trouble if clerk doesn't know or care enough to ask what he's trying to build.
Another familiar confusion between component and composite is the use of bullet for cartridge. Wrong, but seldom confusing and very rarely harmful.
ok, dunc... have it your way... when you call up a material supplier and tell them you want 10 yards of "gravel " to top your drive way, and you get "bank run " with sand and stone from 1/2" to 2' ... lemme know about common useage then..
specs are specs... words are what get us in trouble.. if you don't know the jargon or the correct terminology , you ought to take the trouble to find out before you spend your money..
now suppose you tell us what the correct terminolgy is Mike Smith Rhode Island : Design / Build / Repair / Restore
>> ... when you call up a material supplier ...
Around here, if I ordered "10 yards of gravel to top my driveway", I strongly suspect I'd get 3/4" crushed rock. I'd be surprised to get road base, but not very surprised. I'd be deeply surprised to get bank run, because bank run is not useful for topping a driveway, and I'd expect the supplier to know that.
>> now suppose you tell us what the correct terminolgy is
What I'm telling you is there's no such thing as the correct terminology. When you call up a material supplier, your precise definitions of gravel, rock, and stone are "correct" because your suppliers (presumably) use the same definitions. When you're trying to communicate with BT readers, those definitions are less useful, because the same definitions aren't commonly used everywhere BT readers live and work.
dunc... what a bunch of bsMike Smith Rhode Island : Design / Build / Repair / Restore
Oh, go away before I taunt you a second time.
you're like a thousand years old ...
aren't ya.
hey ... look out ... those damn kids are on your lawn again!
Jeff
Buck Construction, llc Pittsburgh,PA
Artistry in Carpentry
You're right about the supplier helping you--when I was widening a driveway I told the guy I thought I needed "stone mix". He kindly asked what I was using it for and then told me "stone mix" is right, though he and the Road Commission and the state highway dept. call it "A23" (I think that's what he called it). I had also figure the cu. yds I thought I needed, but they measure in tons. He said three tons in this case would be pretty close to three yards. Actually had a little more than I needed, but better than too little, since there is a delivery charge. The guy who delivered it was nice enough to tell me my idea of putting the truck so one set of wheels was at the edge of the concrete drive and the other in the lawn on the other side of the trench I'd dug would succeed in crushing the edge of the driveway and leaving wheel tracks in the lawn. I think they're more helpful when you go in without an attitude that you know more than they do.
Best to put 4-6" of crushed stone, 3/8" to 3/4", or coarse sand, under the sidewalk. Place a layer of filter fabric under the stone or sand.
As for terminology. Everywhere's different. Around here, I ask for gravel, I get bank run, unless I specify crushed gravel, then I get road base. Crushed stone comes in several sizes, ranging from about 1/4" to 4", bigger than that it's "trap rock" or generically, 'rip-rap'. 12" size and up is generally just rock. 'River gravel' is stones ranging from 1/8" to 2", rounded, and generally pretty rare becuse you can't dredge rivers for it here. Then there's many different grades of sand, including mason's sand, dead sand, road sand (which is more stone than sand), mound sand (for septic systems) and bank run sand (which can be nearly anything).
If I want stone or rock, I ask for crushed stone. I specifically have to ask for washed stone, or I get crusher run, which has a lot of fines (which, when washed out, generally gets sold as dead sand). If I want gravel, I have to ask for bank run or crushed and then specify the maximum size. I can also get screened gravel, which is basically bank run but leaving out the large stones. Bank run varies widely and can be mostly stone or mostly sand. My driveway is a shale-based bank run that has a lot of silt and stone dust in it, and is as hard as concrete. 18" of that over filter fabric, and I can't get it to move unless I dig it up. If I went to the other side of town for bank run, I'd get a river cobble based gravel with mostly coarse sand and very little fines, and it would roll all over the place, even with compaction.
Jon E, PE
"when you call up a material supplier and tell them you want 10 yards of "gravel " to top your drive way, and you get "bank run " with sand and stone from 1/2" to 2'"
Not around here.
There are two types of rocks available here. Local quarried/mined limestone or river rock that is trucked in.
The trucked in stuff is much more expensive and used for decorative work. You will typically find it at landscape suppliers.
No one would sent out river gravel with specific requiest and will incude the river/area (color) that it comes from.
After seeing this discussion here and other forum there is only one way to discuss this and that is to use the physical characteristics.
I got into this on another forum with someone about 3/4" with all of the minus used as a base under pavers. He called it grade 8 and claimed that EVERYONE knew what it was. I called the salesman for a larger quarry that has operations in several parts of the country. He did not have any idea what grade 8 was but called out size 8 based on some spec and a couple of other, but none of them was base material.
Around here it is called AB3 or road base. On Ask this Old House I heard them refer to it as "pack". In an other thread I see that WorkshopJohn used a different term, but don't remember what it was.
very true... you have to know what the spec is for the local jurisdiction...
as contractors we bid on specs, if you don't want to wind up in a pzzing contest with your customer or supplier , you should take the trouble to define termsMike Smith Rhode Island : Design / Build / Repair / Restore
When I worked for a nameless county, they solved the problem by having the supplier provide the specs. That way we always got what the supplier had! ;-) (Much the same as the idea of having the inmates run the asylum.)
I always thought that when people say "stone" it just meant that they were from the right coast. Out here on the left coast, we don't have stone - only gravel or rock. With a few variations such as crushed rock or washed gravel...
Oh, and we have creeks instead of brooks.
what's your point ?.... you are still differentiating between rock & gravel..
either way , if you want a product, you have to know what the specification is..
in most jurisdictions the State DPW has defined all of the products for state contracts.... those definitions and specifications are what governsMike Smith Rhode Island : Design / Build / Repair / Restore
back on subject - I agree with Mike - I think the perfered method for a sidewalk is to use a base of compacted stone
Back to the original question. Here in SoCal with clayey soil, those who place sand under their sidewalks, driveways and patio, will usually have problems with tree roots. Root travel thru sand very easily.
It depends on how much you want to spend. If the soil is clay, it will heave. Cutting a trench in the clay and filling it with a few inches of sand would not be much better, because the sand won't drain anyway sitting in a clay trench.
Dirt doesn't expand when frozen, water does. So, to prevent heaving you have to support the sidewalk on a base that contains no standing water. This requires both a base material that will drain by gravity, and a path by which to drain.
So the best way to proceed is to dig deep enough that you can install some type of drainage pipe. The depth and slope will depend on the length of your sidewalk and how you can slope the drain to carry the water away. Surround the pipe by a material that drains freely. Crushed stone is better than rounded stone because it will compact well and stay in position. Use stone of a single size, say 3/4" or so, so it drains. Above this, you can place a few inches of crusher run, which is crushed stone containing mixed sizes down to small stone chips. This drains less well, but compacts solidly. You can top this with a couple of inches of sand if you wish.
You can forego the pipe if there is sufficient slope so that the water would drain along through the stone out to a clear discharge somewhere.
Granted, this is more than most people do. Whether you go to this extent is a balance of cost vs. the quality and longevity you seek.