Driveways have to be built with a stable sub-grade anyway but especially when Paving a driveway. The pattern of pavers laid remember has NO strength laterally and is totally reliant upon the strength of the sub-grade underneath it. So if you are wanting to do it yourself be prepared to be doing a little work.
Now, because of the problem we can have with the existing ground having variable content like stone, organic matter, sand, and even major rocks under the surface, it will effect, not only the compaction but the volume of water or moisture it will hold. You might think that you can seal the top from water but it will be absorbed through the ground, even rising up from underneath.
So when Paving a driveway or any Paver Laying for that matter, it is critical for you to create a base that is stable, that will support and not subside under the weight of the vehicle you intend putting over the surface. So the bigger and heavier that vehicle the stronger the sub-grade has to be. It is far better to be considering this and putting in the effort needed before you start paving a driveway then to have trouble at a later date with sinking, then having to try and fix the problem !!
I cover a lot of the basic information in the Paver laying section that will help even more when wanting to do it yourself, the methods listed below are job specific for a driveway so make sure that you look at the paver laying page too for more tips….
ROAD BASE SUB-GRADE.
It will be normal practice and under normal conditions to have a compacted 100 mm (4”) thick of 20mm (3/4”) Road base material minimum, this can vary up to 150 mm (6”) thick. Remember that is the compacted thickness, not the starting thickness.
This size of the Road base needed will be a 20 mm (¾”) and have a compaction rating of 8 to 12% depending on the moisture content weighs in at approx. 1.6 ton to the m3. This will help with working out how much base you will need, here is a simple calculation for you to see.
To work out what you will need I will work on a scenario of the following, you will have to measure your own area and put your measurements into the formula:
The area you wish to pave for your driveway is 10.0 m (30’) long and 3.0 m (10’) wide so our formula so far will read like this:
10 x 3 = 30 that is 30.0 m2 of pavers So for you, just multiply the length X width = m2
Then we calculate the thickness of the road base remembering the compaction…
if we want 100mm thick minimum then we will allow 112mm (4 ½”)
30 x .112 = 3.36 m3
then we multiply by 1.6 ton per cube
1.36 x 1.6 = 5.4 ton.
So you will be ordering 5.5 ton of road base for the sub-grade.
This is then spread out to the shape and depth that we need see Paver laying for this procedure,
Now the sand that we use when it comes to laying pavers has to be a sharp sand. This simply means that it has NO Lome in it like brickies sand does, that’s what we call fat, it goes spongy when wet. You need it to be a gritty sand like concreting sand. This is very important especially if we are paving a driveway, because of the weight of the vehicle. The calculation is worked out in a similar fashion except that this sand weighs in at approx. 1.2ton per m3 and is laid in at 50mm (2”) thick. So it goes like this…
30m2 x .05 = 1.5 m3
Then we simply… 1.5 x 1.2 = 1.8 ton
So I would order 2 ton of sand, which doesn’t have to come on site till after the road base has been compacted. Again see Paver laying section for the procedure to follow for this. The actual procedure for preparing the bedding sand is the same, no matter whether you are paving a driveway, patio or paving your paths.
The only extra you will need will be the concrete for the edges, which we will discuss now.
Usually when laying Brick Pavers the pavers for the borders are laid in a pattern called a soldier course, which is “Side by Side”. With this procedure the border is laid at the same time as the internal pattern, it is probably easier for you to do the border now, as the border is on the same even plain as the internal pattern. These need to be tapped down with a mallet to the finishing height and then cemented on the out side. It’s a good idea to keep the concrete lower from the top edge say half way down the thickness of the paver, this will allow you to have either grass next to the drive or even have a garden and cover over this concrete.
Another method is to fully concrete the border in, this makes it more secure and a stronger job at the end of the day… if you choose this method, the border is laid on a concrete footing usually on top but dug into the Road-base sub-grade and the Pavers are set on top of this footing and rise above the Road-base to the thickness of what your sand bed will end up being. Just ensure that the Brick Pavers are set in the boarder the same even plain as they will be laid in the driveway.
If you choose this method I tend to replace one part of the sand ratio with a brickies sand, hence making it easier for the paver to bond, also just before setting the paver onto the concrete dunk it in a tub of water, this will rinse off the dust and also help it bond better.
LAYING THE PAVERS.
When it comes to start laying your pavers consider the following:
you will need to start off against a straight edge, this will help your laying further down the track, also choose which way you want to lay that will benefit you the most with cutting, your landscape theme, the direction of the surface water etc. the pattern you choose will have a lot to do with the amount of cutting you will need, so choose wisely. As far as the type of pavers you can lay, your choses are really any of the clay brick pavers or the interlocking concrete pavers providing they are all driveway rated.
For more on the methods see Paver laying and follow the procedures as they will be the same for any job. The main difference for laying a driveway is the amount of preparation and materials needed to do the job properly. Don’t let this discourage you when you attempt to do it yourself, like any of the landscaping projects, if you follow the procedures and get the right amount of materials and are prepared to do the work then you will reap the rewards of satisfaction.
If your Driveway is on a slope then if possible start laying at the lower end, this helps keep the pavers together and avoid the pattern from spreading. if you have to start at the top of the slope and work to the bottom, just be aware that the more you walk on the pavers during the laying they can have a tendency to spread a bit and will need tapping back in, this can be done after laying several rows, just with a rubber mallet belting the edge of what you have laid.
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