How to Lay Wetcast Pavers (DIY)
• Edge restraints either concrete or timber
• String line and 8 pegs
• Plate vibrator/compacter
• Cutting equipment – brick bolster/paver splitter/masonry saw
• Strong line level
• Piece of timber 100mm x 75mm x 500mm
• Spirit Level
• Screed Board (hire)
• 2 Screed Rails 40mm x 25mm x 3m long
Step 01: Site Preparation
Time spent in preparing the site will be well rewarded in the long run. Your paving will be only as good as its foundation.
The base must be firm. Hollow and low areas must be filled and compacted using a plate compacter. Excavate the area to be paved to the depth of the paver plus approximately 30mm to 50mm for bedding sand.
Be sure to allow a fall for draining. Set all string lines first to establish a level starting point, then adjust for drainage falls as shown below. It’s a good idea to get a ‘bobcat’ in to prepare the site for you, particularly if it is a driveway or large pergola. Slope paving away from house of building and allow for final paving surface to be below any damp-proof course.
Step 02: Spread Bedding Sand
Place bedding sand and spread evenly over area to be paved to a depth of 50mm allowing 8mm for settlement on compaction. Spread with a rake. Don’t try to compact the sand as it does not compact in a loose state. Compaction comes later. Set string lines to desired levels and set screed rails accordingly.
Step 03: Laying the Pavers
Work to the pattern you have chosen by building it forward in rows. As you lay each paver, do it carefully so the even bed of sand is not disturbed. Lower each paver against the face of its neighbour. This is called butt-jointing but will actually leave a small gap between the pavers. This gap will be needed as you will see later.
As you work you can stand or sit on the pavers you have already laid. But avoid putting any weight on the leading row of pavers as they can tilt or slip and ruin your even bed of sand. It’s also a good idea to walk on a few pieces of 3ply board measuring approx. 500mm.
This is the time to include the header or soldier course in the design of your pavers. We think it is important, as it both looks professional and helps you start with a good straight line. Running a string line for every metre of pavers laid will help you keep your job nice and straight. The idea is to adjust the pavers each metre to prevent bows from developing.
Step 04: Cutting Pavers
As you work you will find you will have spaces too small for a whole paver. To fill these holes you’ll need to cut a paver to size. Just measure and make the required cuts on the paver itself.
Then you can make the required cuts by using a wet saw.
These can be hired for the afternoon from your local hire store. The cut piece should fit neatly, leaving a small gap all around just like the full paving units. Remember to wear safety glasses.
Step 05: Placing Edge Restraints
The edge restraint locks in the pavers at the edge. Without a restraint these edge pavers could loosen and slip out of position. Of the several different ways to build an edge restraint, one of the simplest is the hidden concrete kerb.
Dig a trench along the paving edge. It must be deeper than the bedding sand into the roadbase.
Concrete is then shovelled in place and formed against the pavers allowing sufficient space for soil and turf. When it dries, you will be able to cover this kerb with soil and plant grass right up to the paving edge. Make sure the concrete does not go under the pavers as it will prevent compaction in the next step. Be careful not to get concrete on the surface of your pavers as it is almost impossible to remove. If you do, sponge off quickly.
Also leave the edge restraint to go hard overnight before compacting.
Step 06: Joint Filling & Compacting
The best way to lock the paving in place is with a plate vibrator or compacter machine which compacts the bedding sand. Make sure you have carpet underneath the compacter. However for small areas, manual compacting using a rubber mallet, a good piece of hardwood and a bit of sweat will achieve the desired results.
Before you start compacting, spread some joint filling sand or gap sand over the pavers. This helps the plate slide easily and minimises any scratching.
You’ll actually be doing 3 things. First you’re compacting the sand into a firm bed for your concrete pavers and secondly, the vibration forces sand up into the gaps between the pavers, locking them in so they won’t shift. Thirdly, the gap or joint filling sand will go down in between the pavers to further block them up. This also achieves the gap between pavers required by the manufacturers.
Step 07: Final Sweeping of Joint Fill Sand
With the compaction completed, sweep some more joint filling sand or gap sand across the paving and work it into the gaps as you go. Then finally sweep the excess sand off the paved area. You may now want to give it a light hosing down.
Enjoy your new pavers!