How to Lay Paving Slabs
Laying paving slabs is a useful skill to learn as it will allow you to construct paths and patios. In this guide we provide you with full step-by-step instructions and an excellent instructional video to help you lay paving slabs that will not lift or sink and will look beautiful for years to come.
In order to successfully lay paving slabs you will need the right tools for the job, so here’s a list of what you’ll need:
- Angle Grinder
- Tape Measure
- Brick Bolster
- Brick Trowel
- Club Hammer or Rubber Mallet
- Spirit Level
- Watering Can
- Ear Defenders
Now that you have all the right tools to do the job you’ll need the materials, and here’s a handy list of those that you will need:
- Granular Sub-Base
- Paving Slabs – there are lots of varieties to choose from and prices vary.
- Sharp Sand
Now that you have both the tools and materials it’s time to get started on the project. In the introduction we mentioned that paving slabs can be used for either paths or patios and the principle of laying them is the same.
Start by taking your string and mark out the course of your path. You will need to create a parallel string line so that you have the width of the path as well as the length.
Take your hammer and hammer in wooden pegs along the course of the path both sides and then run the string lines the length of the path. You will now know exactly where your path will run and the overall width.
Quick Tip: Make the width wide enough for two people to stand side-by-side. To save you from having to cut paving slabs to fit the width of the path lay down 2, 3 or more slabs until two people can stand side-by-side. It doesn’t matter if it’s a little too wide providing you have sufficient room.
With your string lines in place you can then take your spade and remove any turf within the string lines. Start by cutting down the string lines and then work your way through the middle of the string lines.
I would recommend you dig down to a depth of approximately 8 inches, to allow for a good bedding surface of sand and granular base.
You should now have your path dug out and next you will need to hammer in some pegs either side at the height of the intended path, which is generally level, or slightly above the grass area either side.
Hammer in peg along both sides every 12 inches and place a spirit level from one side to the one, on the pegs, to ensure they are level to one another.
It’s now time to lay the hardcore base, so take the bags of granular base you purchased and tip these, along the entire length of the path, between the string lines.
Rake these level – you can use a garden rake or your spade to create an approximate level and even depth. Once you have a reasonable level along the length of the path you need to compact this well, so take the compactor that you purchased and tamper down the granular based, along the entire length, until it is well compacted and firm.
You can test it by walking up and down the path and it shouldn’t feel overly loose under foot.
Take your bags of cement and sharp sand and mix these as follows — 1 Part Cement / 9 Parts Sharp Sand. Mix the two well together and then shovel this along the length of the path. Take your rake and rake the cement/sand mix evenly along the entire length of the path.
Side Note: In this step we are using the ‘Dry Lay’ method. However if you want to use a ‘Wet Mix’ then mix 1 Part Cement / 5 Parts Sharp Sand and mix with water until the mixture is pliable. You can then lay the paving slabs by ‘Spotting’ - that is a spot of mortar on each corner and one in the middle for each paving slab you lay.
SAFETY: Don’t forget to wear a Face Mask when mixing cement. It is highly dangerous to breath in cement dust.
Lay each paving slab carefully in place so that the outer edges of the slab are in line with the string line.
SAFETY: Don’t forget to wear your gloves as paving slabs can be sharp in places.
Take a short, thick piece of timber and use this to buffer the impact from the Rubber Mallet as you tap each paving slab down to the level of the pegs you set. Make sure each paving slab is firmly in place with no rocking movement. Take your Spirit Level and run this over the paving slab to ensure each one is level.
If you find that you have to cut a paving slab then this is best done with an Angle Grinder. Firstly measure the amount you need to cut off and the with straight edge, such as a length of timber of metal ruler, mark the straight line with your Brick Bolster.
SAFETY: When cutting a paving slab with an Angle Grinder ensure that you wear Gloves, Face Mask, Eye Goggles and Ear Defenders.
Start the Angle Grinder and working above the paving slab, slowly lower the disc onto the line. Do Not force the disc but instead allow the weight of the Angle Grinder to do the work. You should find that as you work along the line the Angle Grinder will almost pull itself along the line and all you need to do is guide it.
Cut along the entire length to a depth of approximately 1/4 inch and then work back and forth along the line until you have cut through about 2/3 the depth of the paving slab. Rest the slab on a piece of timber very near the cut line and then take your Club Hammer and rap down sharply – the paving slab should break cleanly along the line you cut.
As you lay your paving slabs down the length of your path you will want to create a slight fall, so that rain water runs off. You can do this by taping a piece of wood, 5cm thick, to one end of your Spirit Level. This will create a 5cm slope for every 10 feet of the length of your path.
Check each paving slab you lay, behind and opposite, to ensure that you retain a level and that no edges, from one paving slab to the other protrudes above one another.
This will give you a nice even surface to walk along. If you find a particular paving slab is too low, then lift it and add more cement/sand mix and then relay it.
Once all your paving slabs are laid you need to fill in the joints and to do this you’ll need to make up a mix of – 1 Part Cement to 3 Parts Sharp Sand. Take the mixture and trowel it in the joints and above the slab and then squeeze it into the joints with the trowel, ensuring it is well compacted.
When all the joints have been filled and compacted take a soft head broom or hand brush and sweep away any excess cement/sand mix.
Take your watering can and with a fine rose head attachment lightly sprinkle water along the joints and this will help set the cement/sand mix. If you find mortar on the slabs DO NOT leave it – take a damp sponge and give each paving slab a good clean.
You should now have a beautiful paving slab path. You should give the path a day or two before subjecting it to heavy foot traffic as this will allow the cement/sand mix to cure and secure the paving slabs firmly in place.
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