Interlocking Concrete Pavers provide a strong, long-lasting, and aesthetically pleasing surface as a means to enhance outdoor space, pavements, and driveways.
The beauty of this product is that you can install it in any way you like to form the layout and design that suits your space. Usually, qualified paving contractors will be hired to complete the paver installation job; however, if you are an adventurous and handyman type of person, then you might want to get your hands dirty.
In case you decide to do it yourself, there are certain steps that need to be taken in order to start and complete the pavement job successfully. Before we get into the details of the steps, lets us first understand some benefits of interlocking concrete pavers. Interlocking concrete pavers can:
- gain compressive strength of 45 MPa (which higher than normal in-situ concrete slab strength)
- provide very low water absorption
- be installed without providing expansion joints
- can be used in the lowest loading area up to heavy-duty space
- can be easily replaced in case of defects
- be procured in a variety of colors, shapes, and textures.
- enjoy the long life span of at least 20 years
- be a part of a sustainable construction materials group.
With the right tools and guidance, you would be able to start and complete the installation job without much hassle. Let us look into each steps in details
Step 1: Site Planning
The first thing that you need to do is to get a general idea and view of the site where you going to install the pavers. Make sure to look for the drainage/sump location so that you will be able to plan the flow of the water from your pavement surface.
Logically, you would prefer to make the pavement slope away from the house or area that you plan to use. You wouldn’t want the water to flow into your house. The usual slope gradient of 1.5 to 2.5 percent is sufficient to keep water flowing away from the car park or house.
Mark the area that you have identified and take down the measurements, and any other details that you might need to start the work (like any trees, plants that need to removed or relocated). The boundaries can be marked off with spray paint or by driving in some pickets and tying the string around.
Now transfer those details to spreadsheet and start calculating the amount of pavers, sand, and gravel that you will need. You can calculate yourself; however you could help from the paver supplier.
Step 2: Selecting the Interlocking Pavers
If you start to look around for buying interloking concrete pavers, you may come accross broad range of colors, patterns, shapes, finishing, special treatment, sizes and thicknesses. Despite these various characteristics; generally, they all come in three different thickness, which is 60mm, 80mm, and 100mm.
The 60mm is usually for pedestrian applications, and also sometimes used for patios, car porch, and anywhere with very low traffic or loading. On the other hand, the 80mm and 100mm are usually reserved for heavy-duty applications; such as trafficked roads, ports, yards, and etc.
Interlocking concrete pavements are designed to provide the stability, structure integrity, and strength for long-term durability. A properly designed pavement with selected paver and reinforced with edge restraint can last for a very long time.
In terms of design and style, you’re only limited by your imaginations. With nearly unlimited finishing types available in the market, you can design your space however you want it to look and feel.
Step 3: Tools and Materials
These are the basic tools and materials you will need to complete the paver installation:
- Paver splitting machine (diamond cutter if financially possible)
- Vibrating plate compactor
- Shovels and raking tools to lay down the base material
- Brooms to spread and sweep sand
- Rubber mallet to adjust the pavers snugly into place
- Enough sand (fine and coarse) to accommodate your project
- Enough pavers to cover your area plus some extras for wastages
- Stakes and string to delineate where the paving stones will go
- Any type of levelling tool to even out the working area.
Step 4: Prepare the Base
“THE BASE” is the most important and crucial layer of any pavement. This literally the foundation of the pavement where all the loads will transfer. In pedestrian and patio application these may not be very crucial; however, when comes to the trafficked pavement is extremely important to pay attention to this.
Getting a licensed contractor/engineer to advise on this would be a good idea. Usually, this layer can be anywhere from 100mm to 300mm thick for pedestrian application up to the medium trafficked road. In the area for heavy traffic or load, the thickness can go close to 600mm. Since it involves quite a heavy digging activity deep into the ground, you may hit underground utility lines. That is why it’s a good idea to leave this part of the work to a specialist contractor.
However, if you’re just going to pave the patio, garden, walkway around your house/neighborhood; base preparation is not so difficult process. Just dig down from your existing surface to level to compensate for paver and bedding sand thickness. Usually, for these types of application, the paver would be 60mm and the sand thickness would be about 30 to 40mm. The surface below will become the base layer, and you can just use the plate vibrating compactor to compact that layer.
Step 5: Spreading the Bedding Sand
Bedding sand acts as cushioning for the paver units to lock into their position. The minimum bedding sand thickness is 30mm and the maximum is 50mm. In any case, the sand layer cannot go above 50mm. This is because the sand cannot be compacted down to firmly bind and lock the paver to the base layer; thus creating a layer of “floating” sand. It won’t seem like an issue in the beginning, but in the event of heavy pour or water ponding; these sand layers will start to move below the paver and eventually breaking the interlocks between the paver units.
The type of sand used should be in compliance with BS EN 12620 grading requirement. Not only the sand must be in compliance with the standard for grading, but it must also be clean and free from any debris, roots, and etc. This affects the pavement stability during and after compaction as the paver units are unable to seat it completely.
Once you spread out the bedding sand over the base layer, use the raking tool to even out the sand throughout the pavement area. Set an interval and measure the thickness to make it stays within the allowable tolerance. Do not compensate the low-level area with a sand layer beyond the allowed limit. In the event of an uneven base; repair that area with proper base material and compact until it reaches the desired pre-sand level.
Level the whole to-be-paved space evenly, and make sure no one steps on it. Ideally, the pavers should be laid immediately while the sand is still intact. However, for any reason you’re unable to start laying the paver immediately; cover and protect the bedding sand in any way possible in order to avoid external force (load and water).
Step 6: Getting the Edge Restraint Done
In interlocking concrete paver work, edge restraint can be considered as the “Ultimate Protector” of the whole pavement integrity and stability. You can use exsiting perimeter wall as edge restraint (if you’re paving around your house).
If you’re going to prepare new edge restarint for your pavement space, then you have few options. You can use the same paver units that you going to use for your pavement work for edging as well. This option will give you same edging color/design with the overall pavement. The edging pieces need to be secured to the ground with wet concrete.
Next option is to use specially manufactured edging block or kerbs. These are also need to anchored to the ground with wet concrete, and also need to make sure that these blocks are made with concrete grade of at least G30.
Once you start laying and come close to the edge, you will realise that you need to trim some pieces to fit inbetween the last paver unit and edging. These pavers can be easily trimmed with diamond cutter or paver splitter. What ever method you chose to use, just make sure that the pavers are not splitted smaller than 25% of the overall paver dimension.
Step 7: Installing the Pavers
By now you probably have decided on the design layout and laying pattern. If you haven’t, then stop all other work and get that out first. It can be laid in stretcher bond, basket weave, stack bond, herringbone pattern. If you want to lay it in a random pattern, then it advisable to draw it out on paper or cardboard before you start the laying work.
When you start to place paver units in the bedding sand, place evenly and gently without creating any major movement to the sand layer. Adjust and push the pavers to fit in tightly with the adjacent paver unit. Continue till you finish installing all the paver units. If need to apply extra pressure to push the units in, use a rubber mallet (no iron hammers).
Step 8: Compaction
You’re almost done. Now you’ve completely laid out the paver units and restraint it ad edge. Now it’s time to bring out the vibrating plate compactor to press and lock the paver units in. Spread a light layer of sand on the pavement surface and start running the plate compactor over the surface. Make sure every area is covered. This is the first phase of compaction which creates the initial interlocking and the joint filling sand will partially fill up the gaps.
After the first round, check the level and make adjustments if necessary. Spread the filling and again run the compactor again, and by now all the pavers should be tightly interlocked.
As an added protection to the paver surface, you can use a compactor pad or plywood of the surface before running the plate compactor.
Step 9: The Finale
Finish up your pavement with joint filling sand. The first option is just to use ordinary sand similar quality to your bedding sand but finer. Just spread it over the pavement and sweep it in between the paver joints.
The second option is to use special-purpose high-performance joint filling sand. These are known as polymeric paving sand. The sand comes in different colors to compliment many styles and design ideas. It also offers longevity and durability by preventing erosion, frost damage, and weed growth.
The goal of this sand application is to fill every joint space between the paver units. Just spread out the sand over the pavement surface sweep it in with a broom until all the joints are full.
Sweep away any excess from the surface, and it is not recommended to use any blower to remove the excess. Use a light mist of water to harden the sand once you complete the application. The joint sand will take few days to set.
If you wish, you can apply a layer of sealant over the interlocking concrete units. This helps the paver to resist stains from oil, weed, algae, and etc. However, it is not a complete and permanent solution. The sealant layer is also subject to wear and tear, so it is important to re-seal it as per sealant manufacturer recommendations.
Apart from resistant from external contaminants; sealant also brightens the color and locks the joint sand in place.
Like any concrete product, Interlocking concrete pavers also will be subjected to efflorescence effect. You can read more about it here. Just make sure you remove the efflorescence powder or wait till it disappears before applying the sealant.
Summary
It is nice and fulfilling when you get to complete your pavement work by yourself. But remember it is not an easy task and can be daunting as well. Therefore, it is always advisable to get the assistance of qualified interlocking concrete paving contractors to advise and complete your work.
The guide provided here can be used by anyone (anywhere in the world) who wishes to start their DIY paving work.
