Every concrete driveway I have ever seen seems to suffer the same problem. That is, the slabs are @ 15 feet wide...they only put joints in to divide the LENGTH of the driveway up into sections. I have seen some driveways flare out near the end to a slab that is 20 - 25 feet across. Each of these slabs has the weight of the vehicle on their outer edges, and so they crack down the middle eventually. My driveway for instance is 20 feet wide (or so) by about 120 feet long. The length is divided into 5 sections. Why not divide the length in half as well? Then each slab will bear the weight in its center?
1
2
-
June 1, 2009 9:26 a.m. pinchvalve UltraDork
-
June 1, 2009 9:40 a.m. Dr. Hess PowerDork
I'm not a civil engineer, but my friend is and they are the people to ask. It isn't the length or width that is making it crack, it is the lack of steel and concrete beams. A proper concrete driveway needs to be built almost like a proper slab, something else that contractors don't do.
-
June 1, 2009 9:43 a.m. 914Driver Dork
The base under the concrete is a contributor. 15" of crush n' run rolled over with something heavy will last longer than a slab of concrete poured onto clay.
-
June 1, 2009 9:51 a.m. Duke Dork
Concrete is going to crack, either from shrinkage or differential settling. Control joints just let it crack in a controlled manner.
4" of concrete with 6" x 6" wire mesh fabric reinforcing, on 8" of compacted gravel, should be fine for a residential driveway. Control joints (scored grooves) every 8' or so should do it for a driveway. About every 3rd control join in a long driveway should be an expansion joint (1/2" wide joint with a cork or asphalted-felt filler).
-
June 1, 2009 10:00 a.m. John Brown MegaDork
Cracks are also a result of fluid movement under the slab. The gravel base alloys for fluid transfer while allowing for reduced compressibility versus sand or clay.
The plan for the father in laws drive (Y shaped starting at 24' ending in over 60' width, approximately 75' long) includes a 6" layer of compressed sand, screen, 14" of crush rock, screen, and final concrete.
His drive will cost more than my mobile did.
-
June 1, 2009 10:38 a.m. Keith UberDork
My wife works for a paving company that also sells concrete. We have a gravel driveway. Tells you something...
-
June 1, 2009 10:40 a.m. pigeon Reader
My concrete driveway was poured as one large slab, and then the control joints were sawn into it. Same way with my stamped colored concrete deck out back. Weird but standard practice in the Rochester, NY area. My driveway has a joint running up the middle of the driveway length-wise, as does every other one I've seen here and in Buffalo, where concrete drives were standard in the suburbs where I grew up.
-
June 1, 2009 10:41 a.m. pigeon Reader
Keith wrote:
My wife works for a paving company that also sells concrete. We have a gravel driveway. Tells you something...
Yeah, concrete is hellaciously expensive!
-
June 1, 2009 10:52 a.m. Wally UberDork
My father had a concrete driveway put in about 25 years ago. He wanted it to support his soda truck when he kept it home overnight. I don't remember all the details but they dug out quite a bit of dirt, and it has rebar in it. so far it has one crack about two feet long in it and as not moved an inch. When the time comes for me to look at driveways I will have him reach out the bill to see what was done.
-
June 1, 2009 11:59 a.m. Adrian_Thompson New Reader
Keith wrote:
My wife works for a paving company that also sells concrete. We have a gravel driveway. Tells you something...
How do you deal with winter and snow? Gravel looks great, but I don't want to spend the whole summer raking the grass as I"ve dumped the whole drive way on the lawn with the snow blower.
-
June 1, 2009 12:11 p.m. Keith UberDork
We don't get much snow where I live - none, really. But I grew up shoveling snow on our gravel driveway in Ottawa, Canada. You don't dig into the gravel, that's all.
-
June 1, 2009 12:19 p.m. Duke Dork
Plus, when it's gravel, it doesn't need to be shoveled as much for traction.
-
June 1, 2009 12:37 p.m. mad_machine UltraDork
I have gravel now.. I would like to put in loose brick with sand between.
Growing up the driveway my parents had was weird. it was in three sections across.. the outer two were for the wheels and the centre was concave to allow water to flow out to the street from our mostly concrete backyard.
The stuff in the back was in 5x5 foot sections with expansion joints between
-
June 1, 2009 1:08 p.m. porksboy Dork
2500' of gravel ending in 20'x30' pads at the garage and shop doors. I had expanion joints put in the pads. The driveway is #7 (i think) with crusher run on top. We have had 90000 pounds plus truck drive down the driveway with NO issues. Of course that wasnt on the pads. No way in hell would I waste the money for a concrete or asphalt driveway. (unless I won the lottery)
-
June 1, 2009 1:52 p.m. sachilles Reader
When I plow on my gravel driveway, my plow has little feet on the bottom, that keeps the plow a inch or two off of the surface. Once everything is frozen it isn't a big deal.
-
June 1, 2009 4:37 p.m. Jensenman MegaDork
The front garage (22x24) and driveway have lengthwise and crossways expansion joints, the driveway to the Garage Majal has expansion joints every 15 feet or so and the 'tapered' section which meets the shop has control joints sawn into it. The Garage Majal (26x26) has no expansion or control joints and it also has no cracks.
-
June 1, 2009 4:43 p.m. porksboy Dork
The only problem I have with my gravel is sticky street tires pick up the dust and stones when I come back in after a spirited run and then throw it up into the wheel wells. I dont care other than it is a bit dirty when I work on the car. I do hose it out regularly tho to keep the rust at bay.
-
June 1, 2009 6:13 p.m. mad_machine UltraDork
my problem with gravel is my feet picking it up and depositing it inside the car
-
June 2, 2009 9:21 a.m. Adrian_Thompson New Reader
OK, I love the look of gravel, but I just don't want the issues with snow, getting on the street/grass, stopping weeds etc. It seems like too much hassle. Our driveway is 16 1/2 feet with by approx 63 feet long with a culvert that needs the retaining walls replacing as well. As far as I know the concrete is original which makes it 56 years old, it's now breaking up badly.
We've been getting quotes to replace it and some the path to the front door and round the back. Forgetting the walks for now, quotes for the drive have ranged from $4,300 - $4,800.
I'm considering doing it myself, initial costs seem to be;
1. Concrete - approx $1,600 delivered (16 cubic yards, 4" for most of the drive and 6" for the first 20"
2. Dumpster skip - $400 - 1 week, delivery we fill it they take it away and dispose of it.
3. Jack hammer - $160 for two days rental
3. Wood for forms - $200
4. Wire mesh for reinforcements - ??What else? It looks like material could easily end up at over $2,600 by the time I've priced the wire mesh. That's a lot of work to save less than $2,000.
How do you put in the expansion split's? Do you rent a saw and cut them in once cured?
I may just pay to have it done.
What else have I forgotten?
-
June 2, 2009 9:32 a.m. Duke Dork
You can either sawcut them in the next day or score them in wet with a scoring tool after floating and screeding. Expansion joints are typically done by pouring adjacent areas in a checkerboard pattern - form up every other area, pour it, finish it, let it cure, remove formwork, apply joint filler, then pour in the other blocks.
For what you're talking about, I wouldn't even consider doing it myself. Especially not with a culvert involved.
-
June 2, 2009 9:38 a.m. Wally UberDork
If they really want less than $2000 for labor, pay them. I helped do a garage floor once, and I won't do it again for any price.
-
June 2, 2009 9:42 a.m. Adrian_Thompson New Reader
Duke wrote:
You can either sawcut them in the next day or score them in wet with a scoring tool after floating and screeding. Expansion joints are typically done by pouring adjacent areas in a checkerboard pattern - form up every other area, pour it, finish it, let it cure, remove formwork, apply joint filler, then pour in the other blocks.
For what you're talking about, I wouldn't even consider doing it myself. Especially not with a culvert involved.
Forget two pours, it would have to be a saw cut, more $$ to rent.
Why wouldn't you DIY?
-
June 2, 2009 9:55 a.m. Karl La Follette Reader
Ask for higher PSI concrete for cars and get fibreglass thread in it . definetly an easy diy project . You need a bowl float to ease the rock down to get a smooth surface . Advertise On Craigslist for some help !! Some old timer well do it and you will save money .
-
June 2, 2009 11:52 a.m. Adrian_Thompson Reader
Karl La Follette wrote:
Ask for higher PSI concrete for cars and get fibreglass thread in it .
How high? My FIL insists that I have to have 7Kpsi or it will fall apart the first winter, but he's a notorious over builder.
The only concrete I've done before was a 9x9 slab for my hot tub. Pouring and leveling the concrete was the easiest part
-
June 2, 2009 1:34 p.m. Keith UberDork
Around here, the concrete installers (and small paving operations) are pretty hungry. You might get some good installed prices.
