The correct laying of pavers is vitally important to the overall look of your investment. Your paving should not only enhance the value and look of your property but be practical and long lasting. To ensure that the paving is correctly laid there are several steps to be considered which are outlined below.
PATTERNS & STYLES:
Once you have selected your product you will need to decide on a laying pattern. Pavers can be laid many different Ways and the use of contrasting colours can further enhance the design. Pictured below are some of the more common and practical patterns.
PREPARATION:
It is critical to the long lasting stability of your paving project that the foundation for your pavers be constructed correctly. Essentially there four factors that have to be considered; drainage, sub grade, base course and bedding course.
When paving against a house it is recommended that the top of the paving is a minimum of 70mm below the damp proof course and 50mm with the use of Termimesh. It is also advisable to place a plastic membrane against the exposed concrete of the house foundation.
DRAINAGE:
The objective of good drainage is to prevent the accumulation of sub-surface water underneath the paved area. Sub-surface pooling may reduce the stability of the whole paved area or bring efflorescing salts to the paving surface and thus detract from the appearance and durability of the paving.
To create good drainage the sub-grade or excavated surface has to have a slope so that any moisture will drain to the low point. At the low point a drain should be installed and ideally be plumbed into the storm water drain. Multiple drains or a sump may be needed depending on the size and location of the paved area.
SUB-GRADE:
The sub-grade is the upper part of the soil, natural or constructed, which supports the loads transmitted by the overlying paving. The sub-grade should be well drained and compacted prior to laying the base course.
BASE COURSE:
The base course is the foundation for the pavers and will vary in thickness depending upon the type of sub-grade and the application. This thickness will vary between 100mm for foot traffic and up to 150mm for vehicles. Quarry rubble is a recommended base course material, which should be compacted at minimal water content to form a firm and tight foundation for the pavers.
BEDDING COURSE:
Sand is used as a bedding course material. The sand must be a well graded course sand (washed river sand) or quartzite sand. It is important not to use clay sands or loams as they are difficult to consolidate and do not form a capillary break. Crusher dust or dolomite are unsuitable as a bedding course.
The sand should be between 25 mm and 35 mm thick and carefully screeded (levelled) with a straight edged.
SETUP & STRING LINES:
Once the base is prepared and you have selected your pattern, the next step is to setup string lines (a grid of string lines spaced at exact intervals around the perimeter of the job). This helps ensure when you lay your pavers they are in a uniform line and don’t bend or curve where they shouldn’t. When setting your lines remember to add 2-3 mm to each paver width to allow for the gap between each unit.
LAYING THE PAVERS:
Place the pavers down along the string lines you have setup. Go back over your work regularly to check your lines and adjust where necessary. Cuts are best done with a brick saw which can be hired from most equipment hire places.
EDGE RESTRAINTS:
It is vital to restrain the edges of the paving to help maintain a strong bonding frame and prevent wash out of the bedding sand. Edge restraints are varied and but will generally be either; mortar or reinforced concrete set at a minimum of 100mm around the paving.
JOINT FILLING:
The cheapest option is to use the bedding course sand as the joint filler. However, bags of “dried sand” are recommended as the dried sand falls into the joints much easier.
Some installers may add 4% by volume of cement to the joint filler which helps reduce the problem of ants and weed growth between the joints. Cement can also be added to the bedding course material if required.
Commercial products such as “Pave Set”, which contain a silicon additive, can be used to help prevent washout and are ideal for larger gaps.
COMPACTING:
Compact the pavers using a mechanical plate compactor. Place a piece of carpet or rubber mat under the compactor to prevent the pavers from being scratched or damaged. After the first pass of the compactor, sweep in more jointing sand and compact again before sweeping off the excess.
SALT STAINING (Efflorescence):
All paving materials contain salts, magnesium and calcium which can cause staining. Some sub grade and base course materials also contain a high proportion of salts. Staining can be caused by the migration of salts by capillary action to the paving surface. If the drainage provisions and bedding specification above are adhered to, the risk of efflorescence or salt damage is minimised.
SELECTING A CONTRACTOR:
If you feel that laying your paving is not for you, then experienced contractors are available to complete your work. It is recommended that you use only an accredited paviour. Inspect previous, if possible, to ensure the contractor is capable of providing the finish you require.
MORE INFORMATION:
If you require further information or assistance, please do not hesitate to contact using the details below. One of our paving consultants will be very happy to help you with any enquiries you may have.
