How To Build A Patio
So you want to build a patio! Its not really to difficult to lay a patio, and with some good preparation, and a fair amount of sweat, you should find you can lay your own patio without to much hassle, and by taking time and care to do it right, you'll end up with something that will look great for years.
Ok, so lets get started with the patio foundation. You are going to want your new patio to last a long time, and for that to happen you need to put some good effort into building the foundation right. The foundation is what your patio slabs will lay on for years to come, and slacking in this area can lead to some unwanted effects, the most common of which is cracked slabs, caused by the foundation shifting, or not being thoroughly level. Build a patio right to start with and it will serve you well!
Preparation
The first step is to mark out your desired patio area, you should already have planned where your patio will go and what size it will be but if not then you need to do this first before going any further. Bear in mind that you don’t really want to be cutting any paving slabs yourself as this can be problematic, so try to size your patio to match whole slabs to avoid this.
With your patio plan in place, grab your marker pegs and string and push or hammer your pegs into the ground at the corners of your desired patio area, then use your string to make the guides by tying it taughtly between each of the pegs.
Use your spirit level against the strings to ensure everything is level across the width of the patio, however because you need the rain water to run away from the house you should ensure that as the string moves further from the house it progressively gets lower, around a one inch drop for every 2 meters of patio is about right.
With your patio guides in place you now need to dig out the ground to a depth of approximately 6 inches below the top of where the patio surface, this will be one of the hardest jobs of the entire project and will take some time so be sure to be ready to put in some hard work.
Levelling
With the area where you patio will sit now dug out to a depth of 6 inches, its time to level it with compacted hardcore. To do this you need to fill the area with approximately 4 inches of compacted hardcore, making sure the hardcore is kept as level as possible throughout the area of the patio, and taking into account the required drop as the patio moves away from the house.
Compacting of the hardcore can either be done using a large heavy piece of wood or timber and repeatedly thumping it down on to the hardcore until everything is compressed and level, or you can use a compactor which will make the job much easier and most likely provided a better result than doing it manually with wood.
Framing
Some people like to frame the area of the patio with treated wood, this helps in maintaining the edges of the patio and may assist in ensuring the patio does not shift over time, however framing is not essential and provided you prepare and lay the slabs correctly is not usually required.
Now with the foundation complete, lets get busy with...
Laying The Patio Slabs
With the preparation complete and the hardcore foundation in place and level, its time to start laying the patio slabs themselves. While laying the slabs themselves is clearly important for the success of the patio, remember that the slabs ultimately rely on the foundation for support, so don’t start this phase until you are absolutely satisfied that your foundation is ready.
Preparation
Before you get going with the mortar, first of all you need to dry lay the slabs. Starting in one corner, dry lay the slabs using the spacers until all the slabs are in place. Now is the time to check you are happy with the design and size of the patio so make sure everything is good before moving on.
Slab Placement
Now you have tested the placement of your slabs you can pull them back up again and put them to one side in preparation for laying them for real. Mix your cement to around 1 part cement to about 5 parts sand, bear in mind that you don’t want the mix to be sloppy so don’t overdo the amount of water you use in the mix.
With your mortar ready you can move to the first slab. Lay a bed of around 2 cm of mortar under where your first slab will go, ensuring your mortar spreads for some inches beyond where the slab itself will lay, then place your first slab on to the mortar.
Use a rubber mallet to press the slab into place on the mortar, check thoroughly that this first slab is positioned correctly, the entire patio will be placed relative to this first slab so any mistake here will be magnified as you work across the patio.
With your first slab in place continue to lay mortar and place further slabs working from your first slab, using spacers as you go to ensure consistent gaps. Use your spirit level constantly to ensure your patio remains straight across its width and that the slight drop away from the house is maintained as the patio is laid.
Finishing
Once all the patio slabs have been laid you need to leave it for around 24 to 48 hours before applying the finishing touches, do not walk on the patio or put anything on it during this period, you want the mortar to set exactly how you left it when you laid the slabs on it.
After a couple of days when the mortar under the slabs is dry you can fill the gaps between the slabs with mortar using a trowel, levelling the joints off so they are almost flush with the patio slabs, this allows the water to drain away more efficiently from the patio.
Finally clean up any edges with a brush, removing any excess mortar that may be present, again leave the patio for a day or two before use to give the mortar between the slabs a chance to dry.
With that done its just a case of cleaning up and enjoying your brand new patio in the summer sunshine!
