How To Lay A Patio
What better way to improve your outdoor space than with a beautiful new patio? By using our handy how-to guide, the correct materials and a bit of work you can lay paving to be proud of, so let AWBS show you how. This guide is applicable whether laying a patio, a paved path or a circle feature. Please note this is purely a guide. We would strongly recommend you employ a reputable landscape contractor to lay your paving. We would always recommend you thoroughly research laying techniques prior to taking on your project yourself.
Materials and Tools Checklist:
- Pointing Iron
- String Line
- Rubber Mallet
- Wheelbarrow or Cement Mixer
- Spirit Level
- Tape Measure
- Vibrating Plate Compactor
- Diamond Disc Cutter (Optional)
- MOT Type 1 (Sub-base)
- Mixed Building Sand
- Paving slabs
- SBR Bonding Agent (Optional)
- Brush-in Jointing Compound (Optional)
Before you start
Once you’re happy with your plan, lay out lengths of string to mark out the edges of your proposed project. This is a good time to double check the dimensions of your area. This is important in determining how much paving you need for your paved area.. Most of our paving and project packs at AWBS are supplied in square metre measurements, so it's advisable to have a rough idea of your area in metre square when it comes to ordering your paving. When you are happy you have marked out your area correctly you can begin to prepare the ground.
The recommended depth you'll want to dig to is about 150mm or 6 inches from the finished patio level. You can use a tape measure to check your depth is correct and once you're happy you can compact the soil using a Vibrating Plate compactor, also known as a Wacker Plate. These are available from all good tool hire companies.
If you find soft spots in the soil further excavation may be required. These spots can then be filled and strengthened with sub-base material. It's also a good idea to lay your slabs with a slight fall away from your house or any other buildings, as this will ensure water drains away from your property and will not pool on top of the slabs.
A non-woven membrane can be used at this point to prevent the stone being pushed down into the underlying ground. This has the added advantage of reducing the chance of weeds coming up through your paving at a later date.
Spread a 100mm layer of sub-base, MOT Type 1 on top of the soil. Thoroughly compact using a Vibrating Plate compactor, making sure the area has been compacted at least twice. Check again for any sinking areas and add an extra depth of sub-base material if needed. Level off the area so the hardcore is flat and smooth. It's a good idea at this stage to ensure there is a slight drainage slope away from any buildings too. It's important to remember to follow the manufacturers operation and safety guidelines when using a Plate Compactor, including adequate use of ear protection.
Laying the Slabs
Before you do anything it's a good idea to dry-lay your slabs at this point, particularly if you're using pavers of different sizes. Dry-laying simply means you lay your slabs out in the pattern and arrangement that you want them to be with no sand or mortar mix. This will give you an idea of which slab will go where, how the finished project will look and also if any cuts are required. It also allows you to ensure that your colour mix looks good, and you can move the position of individual slabs around to suit. It's also important to remember to lay your slabs the correct way up. Remember if you're laying sandstone slabs, the main indicator is the edges of the slab should always have the widest tapered side facing up. When looking at the slab as a cross section the slab should get narrower at the bottom, almost in a V-shape. Another tip if you're laying slabs from more than one pack, particularly when using natural stone, is to take slabs from each of the packs as you go rather than laying them one pack at a time. This will ensure that the colour mix will be more consistent and it wont be noticeable if the two packs differ in colour slightly.
When you're happy with the layout of your slabs, it's time to prepare your mortar mix. When preparing your mix try and avoid direct contact with your skin. Always use gloves. Using either a cement mixer or a wheelbarrow, create a mix using a ratio of five parts mixed building sand to one part cement. The aim is to produce a doughy consistency. When squeezed in to a ball a correctly mixed mortar will retain it's shape without falling apart or oozing water.
Starting in the corner, trowel in enough mortar to cover the area of the first slab to go down. The depth of the mortar bed should be approximately 35-40mm deep. Ideally starting from a right angle or straight edge, place the slab down. Gently tap with a rubber mallet or press down with your hands and use a spirit level to ensure to make sure the slab is level and in line with your proposed design. A spirit level is the ideal tool for ensuring your slabs are as level as possible. Remember to take care when handling heavy slabs and get help if necessary. Settle the stone as cleanly as possible without sliding it so a good bond forms between the mortar and paving flag. At AWBS we always recommend laying natural sandstone on a full bed of mortar, this will help to reduce voids which can cause problems in the future and will also ensure the slabs are laid on a firm, strong base which will eliminate movement and ultimately extend the life of your patio. It is also common these days to add an SBR bonding agent to the mortar mix and also to coat the underside of the slab with a SBR slurry mix. This helps the adhesion of the slab and also helps act as a barrier to reduce moisture reaching the face of the slab. Contact your nearest branch if you need any more help with this.
Leave a gap of 10mm between each paving slab to allow a joint which will be filled in with mortar later.
Repeat this process for your whole area, being careful to check your level and the position of each slab continuously. You can check that your paving is level by running your hand across the joints.
Once all of the paving slabs are laid into position you may need to cut a number to complete the area. Cutting the paving is best done using a diamond disc cutter, which again can be hired from any tool hire company. Make sure to follow to manufacturers guidelines regarding operation and safety. Great care must be taken when cutting paving flags and personal protective equipment is very important. Mark the paving slab you wish to cut with a line for guidance. Place the slab on a stable platform and carefully cut.
To finish, fill the joints between the paving slabs using a pointing trowel and a dry mix of mortar roughly, three parts mixed building sand to one part cement. Compress down firmly to ensure the whole joint is filled, then smooth over. Wash down the slabs when you've finished, making sure you remove any splattered or excess mortar before it hardens and stains the paving.
Carefully brush off excess mortar when finished and allow 24 hours to set, leaving your finished patio.
An alternative option when it comes to pointing in your patio is to use a jointing compound. AWBS supply both Pavestone Pointfix or Azpects Easyjoint which is available in several colour options. These easy-to-use powder compounds simply brush into the gaps between your paving slabs. You can then gently compact them down by using a pointing trowel, before leaving it for approximately 12 hours. After this time, the compound has hardened and your patio is finished with nice, neat, hassle free pointing.