Concrete paving around the home can be completed in many instances by the home owner. If careful preparation and laying of the concrete pavers is done with the right equipment the owner can achieve a high quality job.
This guide details the steps to follow when completing the task of laying the masonry paving. It does not contain all the details on pavement construction issues. If you have any doubts or concerns, it is best to seek advice.
Before you start any project around the home it is necessary to carefully plan the work. A plan of the area to be paved should be accurately drawn and marked out on site. Provision for stormwater run-off will be required along with the required services that need to run under the paved area, such as stormwater and water pipes, or pipework for a sprinkler system. If further works are required around the site such as a retaining wall, check that access will still be available after the paving has been completed. It is important to determine the finished levels of the paving when planning the project.
The finished level of the paving must be a certain level below your floor height -- check with your local authorities.
The quantity of materials needed for the paving job depends upon the total area to be paved. This can be determined from measurements taken off the plan or if the area to be paved has been pegged out on site. The area is simply calculated by measuring the width and length of the area to be paved.
Here's the formula: Length (in metres) multiplied by width (in metres) equals the area (in square metres)
Once you have the square meterage to be covered, add 5 per cent to allow for cuts and wastage (only 2 per cent should be required for wastage on jobs greater than 100 square metres).
If a header course (edging) is to be laid in a different type of paver around the paved area, the quantity of paving units can be calculated. This calculation assumes a 100mm by 200mm paving unit is used for the header course.
Here's the formula: Length of header course (in metres) times 10 (allows 10 pavers per metre) equals the total number of pavers.
Then, the number of pavers required times 0.025 (allows 40 pavers per square metre) equals the total number of square metres of header course pavers required.
REMEMBER: deduct the total number of square metres of header course pavers from the the total number of square metres required for your main pavers.
ROADBASE MATERIAL: For every 100mm of depth of roadbase material required to prepare the paved area, allow one tonne of roadbase material for every six square metres to be filled.
Here's the formula: Area to be paved (in square metres) times 0.167 (allows for 100mm thick roadbase) equals the the number of tonnes of roadbase required.
BEDDING SAND: 30mm of bedding sand (washed concrete sand) is required under all paving. One tonne will cover about 15 square metres.
Here's the formula: Area to be paved (in square metres) times 0.05 (this is for 30mm of bedding sand) equals the number of tonnes of bedding sand required.
JOINTING SAND: Jointing sand is used to fill the gaps between the paving units once laid. A 40kg bag will over about 15 square metres of paving, depending upon the size of the joint spaces.
Here's the formula: Area to be paved (in square metres) times 0.067 (allows for 3mm joint spaces) equals the number of 40kg bags of jointing sand required.
CONCRETE EDGE RESTRAINT: Paving not abutting another structure will require a concrete restraining strip; a quarter of a cubic metre of concrete will be required for about 50m lineal metres of edge restraint.
Here's the formula: The length of required edge restraint (in metres) times 0.005 (allows for a 100mm triangular edge restraint) equals the number of cubic metres of concrete required.
The sub-grade is the natural soil the pavement is supported on. This should be a firm, solid base with the top soil and vegetation removed. String lines can be used to determine the finished level and area of paving.
The finished level of the sub-grade should be trimmed to within zero to 25mm of the design level and compacted if necessary. Backfill for service trenches should be compacted in layers to provide levels of strength similar to the sub-grade.
The roadbase for walkways may be reduced on sandy or non-reactive sub-grade. However, it does add considerable strength to the pavement and is recommended for a first-class job. All roadbase material should be compacted with at least three passes of a mechanical vibrating plate compactor.
A 30mm layer of washed concrete sand is required as the final preparation for laying the pavers. The levels of this base will be reflected in the finish of the paving, so it must be accurate. The most effective method to level the bedding sand is to use the two screeding rails set accurately in the bedding sand to the required finish levels and placed about 1m to 3m apart.
The screed board is then used to level off between the screeding rails. The rails are then removed and the tracks filled with bedding sand and smoothed off with the trowel prior to laying the pavers.
The bedding sand is not a levelling medium. The thickness must be kept consistent across the paved area to avoid uneven settlement of the paving.
Remember, the level of the bedding sand will determine the finished levels of the paving, so take your time to get it right, and allow for necessary falls.
When laying the pavers, it is generally best to start in a corner or along a straight edge, such as a house footing. Place the pavers using the desired pattern on the screed sand, leaving a nominal 3mm gap between each paver. Take care to ensure that all pavers are level by using string lines and regular visual checking. Laid pavers can be adjusted with a screwdriver or trowel to correct any minor errors in the joint alignment.
Normal practice for all concrete segmental paving applications is to progressively lightly compact the paving as laying proceeds. This is done by using a suitable plate compactor over the placed pavers as the laying face is developed. This should be done as frequently as practicable and should not be left until the end of the day, or even halfway through a day.
As soon as this is completed, the gaps between pavers should be filled with a suitable joining material. This will greatly reduce any tendency for corner or edge contact even when the specified gaps were made during placing the pavers.
Always work from on top of the pavers that have just been laid to avoid disturbing the screeded bedding sand.
Leave cutting and placing of the edge pavers until the last step. Carefully mark the pavers to be cut and use a bolster and hammer. For a more professional finish, hire a brick saw or brick guillotine to accurately cut the pavers.
Remember to wear proper safety equipment when cutting pavers.
Where the paving does not abut a solid structure, an edge restraint is required to prevent the pavers spreading or opening up. Finishing unsupported edges of the paving with a concealed concrete edge strip is the most common method used to support the pavement edge. The edge restraint should be kept at least 10mm below the finished level of the paving to allow for compaction.
Alternatively, the edge restraint can be an exposed concrete strip, a "soldier" course of pavers with edge restraint, or the edge pavers can be set on a concrete base.
Dry jointing sand should be spread over the surface of the pavers and swept into all joints in the paving. Compacting of the pavement should then be completed to lock the pavers in before brushing off the excess sweep sand.
In some instances it may be necessary to make an additional pass over the paving with the broom and recompact the pavers to ensure all joints are thoroughly filled.
After the pavers have been laid and dry jointing sand spread over the surface and into the joints, the pavers should be compacted. This will bed the pavers down and assist in ensuring all the pavers are level and any minor imperfections are rectified to produce a professional finish to the paving job.
For small areas of paving, a board and rubber mallet can obtain adequate results. However, for larger areas and a more professional finish it is better to hire a mechanical vibrating plate compactor fitted with a rubber or carpet base. A layer of dry sweep sand spread over the surface of the pavers will protect the pavers from damage during compaction.
Samples of the most common laying patterns are shown here.
These provide an attractive finish while minimising the number of cut pavers that are required.
The inclusion of a header course in the same or different-coloured paver can also be incorporated with all the patterns shown to create a feature around the pavement.
Paving around the home is well within the capabilities of a competent home owner -- here are a few hints to help ensure that you produce a first-class job.
courtesy of the Cement and Concrete Association of Australia
and the Concrete Masonry Association of Australia
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