Installation of Paving Slabs
Advice on installing paving slabs for DIY - Natural Stone Yard, close to M50 Dublin Ireland
INSTALLATION OF PAVING SLABS
Getting ready to lay your patio.
Materials you will need:
Hardcore 804 crushed stone
To create a firm base on which to build your patio
To mix with building sand to create mortar to set your paving.
To mix with cement to make mortar to lay slabs on.
Your selected choice of Natural Stone Paving. Jointing Compound
To joint your paving to stop weeds growing between the slabs. Available in colours to match your paving.
To protect your new patio from weathering and stains
Tools you will need:
- Long tape measure
- Builder’s line
- Spirit level
- Builder’s trowel
- Wooden marker pegs
- Safety goggles
- Dust mask
- Rubber mallet
- Cement mixer
- Whacker plate
- Angle grinder
- Large paint brush/roller
Mark out the patio in its desired position using a long tape measure and spray marker Remove vegetation from the marked area, and the topsoil to a depth of 200mm. Hammer in wooden pegs so their tops mark the top of the finished base. If the patio joins a house its level should be at least 150mm below the damp proof course. Use a spirit level to ensure the pegs are level across the width of the patio but allow a 1 in 100 fall away from the house to enable rainwater to run off.
Tip in a layer of hardcore so it reaches the top of the pegs, rake roughly level and then use a whacker plate (which can be hired). If required top up the hardcore and compact again so it reaches just below the top of the pegs.
Preparing the ground for paving depends upon the site conditions and the intended use of the paved area. If your ground is firm you probably only need to remove the turf and topsoil to a depth to accommodate 30-40mm for the slab & mortar thickness.
If the subsoil is wet or spongy you need to dig out much deeper to put in a stabilising layer (approx. 100mm) of well compacted hardcore again allowing 30-40mm for the slab and mortar thickness. In reality few areas are already level enough for immediate paving, so some areas need to be excavated whilst others need to be made up with the compacted hardcore. The use of hardcore helps ensure adequate site drainage, which is a prerequisite for paved areas.
Which way up?
There seems to be some confusion about the way you lay Natural Stone, please see the diagrams below for advice.
We recommend that whenever laying Natural Stone you should mix your paving from 3-4 different packs (where possible) as you lay the patio. This will allow the colours to blend and help to improve any shade variations that may occur between packs, giving your patio a more natural look.
We recommend laying a constant mortar bed to set paving on. This provides a stronger base and also allows for the variation in thickness of natural stone paving. Mix cement, building sand and spread enough on the base to lay 1 or 2 slabs at a time. Ensure that you check all of the levels and falls during the laying process, you should do this by using a spirit level. This will enable you to have a nice level patio and Do Not Walk on the paving for at least 24 hours.
If your patio involves a lot of cutting we would advise that you hire a powered cutting tool with a diamond tipped blade (any hire shop will advise you of the machine and blade you will need if you advise them of what you are intending to do). Please take care and also make sure that your hire shop issues you with full instructions and relevant safety equipment including goggles.
There are several methods and products on the market to help with the pointing of paving products. Air reacting pointing products that can be found in most builders merchants or patio centres, the old fashioned cement and mortar mix.
The joints should be pointed as soon as possible but not if rain or snow are forecast. As with all natural stone products, we recommend that paving is laid allowing for a minimum 10-15mm joint. We recommend joints are pointed using a wet (but not slippy) cement mortar mix to produce a more permanent waterproof finish. Do not leave the joints unpointed for more than a couple of days. You must not attempt to brush the mix across the surfaces of the slabs as any cement left on the slab will result in unsightly staining and will often mean a complete renewal of products.
Natural Stone Yard cannot accept any responsibility for any mortar staining, cutting or problems during the laying of their natural stone paving.