Shifting patios inevitably result from two major mistakes with the initial installation. First, the project was probably laid without a proper base. It is not uncommon for pavers to be laid on a one or two inch sand base. That's probably OK of the first few months, but come winter up here in Michigan, the ground starts freezing and thawing and heaving. The problem is that sand doesn't retain its original position, so when the sand shifts, so do the bricks. Never lay a brick/paver walkway or patio only on sand!
The second problem: no edging. Without some type of edging, the bricks can shift outward. When this happens, the bond between the bricks loosens and causes the general structure of the walkway or patio to fail.
In areas prone to harsh/cold winters, it is essential to start your project with a proper foundation. This means digging approximately seven inches deep for areas receiving only pedestrian traffic or ten to twelve inches deep for areas receiving vehicular traffic. In addition, you must dig approximately four to six inches beyond the area of what will be your finished patio. Thus, if you intend to make a patio that is twelve feet wide, you will dig the hole thirteen feet wide, six inches wider on either side of the patio.
Next, order crushed concrete or gravel to fill four inches deep for a pedestrian area, and six inches deep for a vehicular area. To figure out how much crushed concrete or gravel you need to order, use this formula:
Crushed Concrete
Pedestrian Area:
Area square feet/27 cubic feet/3 * 1.10 * 1.4 tons = total tons of gravel/crushed concrete
Vehicular Area:
Area square feet/27 cubic feet / 2 * 1.10 * 1.4 tons = total tons of gravel/crushed concrete
Dump and spread the gravel/crushed concrete to half of its final depth, two inches for pedestrian area, three inches for vehicular area. Spread as evenly as possible. Don't worry about leveling perfectly.
21AA Road Gravel
Compact using a tamper or plate compactor. I would advise you to use a plate compactor whenever possible. Plate compactors compact more thoroughly and more quickly. They also save you a lot of labor. Believe me, after using a tamper for half an hour, you will feel sore for days. If you do use a plate compactor, you will still have to tamp some edges by hand. You can never get into every nook and cranny with a plate compactor. Failure to compact all of the base will result in eventual collapse of the improperly compacted area.
Once you have finished compacting the first layer, add the remaining crushed concrete or gravel, this time take your time to get the area leveled. If the paver patio or walkway will be against a structure, you will want to ensure proper drainage by sloping the gravel away from the structure.
Half an inch slope for every four feet of distance is plenty.
Once level, compact again. Don't forget to get into those corners. You will probably have to rake and shovel to get the proper slope/level. Get this level as close to perfect as possible.
Now you have your completed base.
Take a can of spray paint and mark out where you would like the edge of your finished patio/walkway. Don't forget, you need to leave four to six inches of compacted crushed concrete/gravel around the outside of your patio. Step back. Take a look from several different places. Try to envision how the patio will look once it is finished. Make sure your lines mesh with your vision. Cross out the lines if you don't like the look. Try again until it looks just right.
Now, time to install that edging. I generally use a plastic or aluminum edging, staked in place with ten or twelve inch spikes. I prefer to be on the safe side and use approximately five spikes for every eight linear feet of edging. This way, the edging tends to shift less. Run the edging along the outside of the line you just made. Brick restraint edging is generally "L" shaped. Face the horizontal part of the edging outward, away from where the bricks will go. Spike the edging in as you go. Remember, you don't need to put edging along any hard edges such as a structure, concrete or asphalt driveways, or sideways.
I have occasionally used landscape ties as edging. However, this only works for straight-edged areas, and the wood tends to rot rather quickly, usually within five to ten years. That means, you have to replace the edging eventually, thus disturbing the brickwork. Not really worth it in my opinion.
I have seen poured concrete curbs used as edging. Again, I think you are looking at a lot more work than its worth. Like most poured concrete, a concrete curb is inflexible. Therefore, if you do not put in a proper base and pour deep enough (i.e. below the frost line which could be 18" or more), you will eventually end up with cracked concrete. Just like those driveways you see all over Michigan. You don't want to replace that and mess up your brickwork. Stick with aluminum or plastic brick restraint. It will last as long as your brickwork so you won't have to replace it.
Once you have finished compacting the first layer, add the remaining crushed concrete or gravel, this time take your time to get the area leveled. If the paver patio or walkway will be against a structure, you will want to ensure proper drainage by sloping the gravel away from the structure.
Half an inch slope for every four feet of distance is plenty.
Once level, compact again. Don't forget to get into those corners. You will probably have to rake and shovel to get the proper slope/level. Get this level as close to perfect as possible.
Now you have your completed base.
Take a can of spray paint and mark out where you would like the edge of your finished patio/walkway. Don't forget, you need to leave four to six inches of compacted crushed concrete/gravel around the outside of your patio. Step back. Take a look from several different places. Try to envision how the patio will look once it is finished. Make sure your lines mesh with your vision. Cross out the lines if you don't like the look. Try again until it looks just right.
Now, time to install that edging. I generally use a plastic or aluminum edging, staked in place with ten or twelve inch spikes. I prefer to be on the safe side and use approximately five spikes for every eight linear feet of edging. This way, the edging tends to shift less. Run the edging along the outside of the line you just made. Brick restraint edging is generally "L" shaped. Face the horizontal part of the edging outward, away from where the bricks will go. Spike the edging in as you go. Remember, you don't need to put edging along any hard edges such as a structure, concrete or asphalt driveways, or sideways.
I have occasionally used landscape ties as edging. However, this only works for straight-edged areas, and the wood tends to rot rather quickly, usually within five to ten years. That means, you have to replace the edging eventually, thus disturbing the brickwork. Not really worth it in my opinion.
I have seen poured concrete curbs used as edging. Again, I think you are looking at a lot more work than its worth. Like most poured concrete, a concrete curb is inflexible. Therefore, if you do not put in a proper base and pour deep enough (i.e. below the frost line which could be 18" or more), you will eventually end up with cracked concrete. Just like those driveways you see all over Michigan. You don't want to replace that and mess up your brickwork. Stick with aluminum or plastic brick restraint. It will last as long as your brickwork so you won't have to replace it.
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