One of the problems encountered with old brick paver patios, is that some areas begin to settle and sink. In this article we will address how to repair a brick paver patio presenting this condition.
How big a deal
The first thing we are going to do is to determine the possible magnitude of this job. Slightly depressed areas of 1 inch or less are going to be a pretty easy fix. Areas that have sunken lower than this are repairable but will possibly need some extra steps.
Where on your patio the condition exists could also determine the magnitude of the repair. The edges and sides near walls are very common areas for bricks to settle and probably the easiest to fix. Brick that are part of a stair tread and have sunken may need to have the containing block part of the stairs repaired as well.
The first thing to do is clear the repair area of any debris such as fallen leaves and just give it a generally good sweeping. You could use your leaf blower as well. Most of the time you are going to be able to reuse the bricks. When this is the case, take a look at the pattern, if it is a repeating pattern, you can just remove the brick from sunken area, clean them and put them to the side out of the repair area.
When the pattern is random or contains cuts, then you need to carefully remove the brick one by one, clean them and place them out of the repair area in the same relative position as when they were removed. Removing the first brick is the most difficult. You will have to use two thin bladed tools, like a pointer trowel, and insert one into the joint on each side of the brick to be removed. Then exerting force on the paver try to rock it out. You could also use a paver extractor for this purpose, if you can rent or borrow one. When all else fails, you could break this paver up with a hammer and buy a replacement.
Remove all brick that is necessary to flatten the area. You can find this out by placing a straight edge, like a nice straight 2×4 across the repair area.
Prepping the base
Once all the brick are removed from the repair area you need to get the base ready to accept the brick. The base should consist of two layers of material. The area you see, after removing the brick should be a course sand type of material. This layer should be about 3/4″ thick. Under that you should find a compacted base of Item 4. A mixture of course sand and small stones. This layer should be about 4 inches thick.
In most instances you will only need to prepare the top layer for the repair. Loosen this layer slightly with a metal bow or straight back rake. Starting on the edges of the repair area, flatten the sand with a masonry float or trowel. Be careful not to compact the sand too much. Using one of the removed brick as a gauge add or remove new sand so that this “gauge brick” is about 1/4″ higher than the brick adjacent to the repair area.
The material you will use to add to the repair area in this instance is either concrete sand, stone dust or a similar course sand. Your local Landscape supplier could probably help you find this item.
Once you have the edges of the repair area prepared as described, take a straight edge that fits the area between the brick, on top of the repair sand and prepare the remaining area. Lightly drag the straight edge across the area on top of the prepared edges from the previous step. Add more sand as necessary. Remember this should not be tightly compacted.
Time for the brick
Once you have your sand base prepared, simply replace the removed brick. These brick should be around 1/4″ higher than the area surrounding the repair. Now take a piece of plywood 1/2 to 3/4 inch thick and about 2 foot x 2 foot. Place this plywood on top of the repair area and pound on top of it with a hand compactor. I get best results with 1/2 inch plywood.
Move the plywood around, compacting your repair area, until you are satisfied that is flattened and even with the surrounding brick. When you cannot seem to get the brick low enough with this compacting method, you may be able to use a plate compactor to accomplish this phase of the repair. These can be rented in most areas.
Once you have the brick installed to your satisfaction, sweep or blow off the repair area again. When your patio has plain sand in the joints, between all applications except the final.all you have to do is sweep fine dry sand across the repaired surface 2 to 3 times, compacting as described between applications.
When your patio has polymeric sand in the joints the steps are similar. Make sure the brick are dry, this is especially important for the use of polymeric sand, as things can get quite messy if they are not. Sweep and compact as before. Once you have the sand installed to its final depth, lightly spray a mist of water over the repaired area. Do not get the area too wet. Follow the instructions on the bag of polymeric sand.
Now your ready
That is all there is to it. Hopefully you have returned your patio to some of its former glory. Even if you don’t feel comfortable doing this repair yourself, now you are armed with some knowledge for discussing your issue with a contractor.
In extreme cases you may need to make underlying repairs to the lower base material but most of the time just repairing the sand base should suffice.
This link is to a video that describes a similar method of repair as I have described. The main difference is that they did not use the same compacting method as I described.