All Your Need to Know About How to Lay a Patio
06th November 2020 / Annie
Paving slabs are available in such a vast range of colours and styles, there is something to suit every garden design. Read our step-by-step guide on how to lay a patio.
What you will need:
- String Line
- Wacker Plate (easy to hire)
- Tape measure
- Spirit Level
- Rubber Mallet
- Semi stiff brush
- MOT Type 1 or similar
- Jointing Compound (optional)
If you are using a mortar mix to set the paving, you will also need:
- Sharp Sand
- Builders sand
- A cement mixer or mixing pallet though the wheelbarrow can also be used.
Step 1: – Ask yourself the boring (but extremely important) questions.
What is the drainage system surrounding the area you want to lay the patio?
You will need to address this as drainage will prevent unsightly surface water and minimise any foul smells which can be created from bacteria growth in standing water.
All of the paving slabs will need to be laid with a slight slope, around a 1 in 80 fall. This is so that pools of water do not form on the surface of your patio. That means that for every 80cm your patio should fall by 1cm. The fall may vary dependent on the size of your patio, but this is the optimum level.
This fall creates a natural run off, so should ideally be directed away from a house. However, it may be necessary to direct this water elsewhere, dependent on where your drain is, and to avoid a sodden lawn!
Are there any cables running below the area I wish to pave over?
It is not a problem to pave over cables, its whether you will need access to the cables at a later date and would be you be prepared to dig up all your precious paving.
If you do have cables running below, one solution would be to safely secure the cables and then lay the patio onto a layer of sharp sand rather than mortar and use small aggregates or sand in between the gaps. This method allows for the paving to be freely lifted up and moved if needs be. However, this isn’t a method we would recommend as the movement of slabs is likely.
Step 2 – Preparation is key!
Firstly – mark out the area
We advise that you mark out the area using pegs and a string line. A straightforward way to make sure you get this spot on is by laying your paving onto the area as a ‘practice run.’ If you are using different sized slabs you can experiment with the pattern to ensure its perfect when you set them in place later on.
Remember: when marking out your area you must include the FALL. This is the gradual slope for drainage. Peg your string at the highest point and then at the lowest, to ensure you don’t go off-course.
Secondly – get digging!
Now that you have the area marked out, the surface will need to be prepped. You will need to remove any old paving, concrete, or turf.
The depth at which you will need your base will depend on where you are laying your paving and whether you want this paving raised or at ground level.
The Typical measurements are a depth of 150mm. This includes a 75mm subbase, 50mm of a mortar mix or sharp sand and then the paving on top of this.
Once you have dug down sufficiently you will need to create a flat base for the sub-base to be laid on. We would suggest thoroughly raking the area at this point.
If your patio is directly next to your house, ensure you dig 150mm or 2 bricks BELOW the damp proof course.
Step 3 – Lay the sub-base
Once you are happy with the depth, you should lay a subbase material for example MOT TYPE 1 to a compacted depth of around 75mm. You will need take into consideration the fall when laying this. Check the surface is level with the top of the marker pegs and then again at the bottom. You can add more subbase and compact if necessary to reach this level. You can compact this using a wacker plate.
Once you have laid your subbase you can either lay a 25mm depth of sharp sand. However, we recommend using a mortar mix as this will provide a longer lasting base which will prevent weed growth and the gradual movement of slabs.
If you are using a mortar mix: – this normally compromises of 1 bucket of cement, with 3 buckets of sharp sand and 2 buckets of builders’ sand. Throw this into your cement mixer (if you have one) otherwise you have the fun job of mixing manually. Then and add water until you have a consistency where it can be moulded without falling apart or oozing water.
Step 4 – Getting the paving laid
Take your time and make sure this is positioned correctly.
Start at one corner, ideally at the highest point. Shovel mortar onto the sub-base, ensuring there is enough to cover the area of the slab. Then use a trowel to smooth off to a depth of around 50mm.
Then wet the back of the slab with a brush, ready to be laid. This will improve adhesion, remove any dirt, and make it easier to slide into position.
Now use a rubber mallet to gently tap the slab to fix it into place.
TIP: In case any mortar has fallen onto the paving, we suggest brushing it off with water straight away to ensure it doesn’t get stained.
When you lay the rest of the patio, leave a gap of between 5 and 10mm between the paving slabs. Each time you lay a slab down you will need to check it is level with the one adjacent. Also use a spirit level to ensure you are continuing the fall.
Now leave it to dry for at Least 24 hours and DO NOT walk on it in this time.
Step 5 – Jointing the gaps
You then need to fill in the gaps between the paving. There are a few options available for this.
You can use decorative stones; we recommend nothing larger than 10mm.
Alternatively, you can use a jointing compound, which is the easiest and most effective method. This will also achieve a colour consistency throughout. Each type of jointing compound has its individual requirements so always read the label! For most you can simply wet the entire paved area with a hose pipe then pour a generous amount of compound onto your paving and sweep or trowel into the gaps. Ensure each joint is full and then smooth down.
You can also create your own pointing mix. For this we recommend 5 parts builder’s sand with 1 part cement and a little water. This will only work for certain paving colour tones.
The best way to ensure the consistency is correct is to lift the mortar out of the bucket you are mixing it in. Then hold the trowel on its side. The mortar should stick to the trowel a bit but not completely.
Now leave the area to dry for at least 48 hours, if the weather is wet (which is highly likely) we would recommend leaving the paved area alone for a week and then voila! Your paved area is complete.
Side Note – Quality control!
It is extremely important when you are picking your paving to take into consideration not only the colour and texture but the quality of the material. Think about how often over the years you will walk across the pavers. You should choose a thickness of at least 2 inches which supports frequent foot traffic and choose stones that are flat and have a natural-cleft surface which offer some grip or texture.
Porcelain paving is the creme de la creme for paving so if you have the budget, we would highly recommend this everlasting, frost resistant, anti-slip paving.
Sandstone paving is a great all-rounder, it is tough enough for any paving application but is easier to cut and work than granite. Its naturally grainy texture helps to make it slip resistant.
Check out our full range of paving and watch our video for a more visual guide on how to lay your patio.