The process of laying paths or driveways using concrete is not as difficult as it may sound. If you have an old pathway that is cracking and becoming dangerous, what better way to renew it than to lay some fresh, new concrete. Ideally the process should go something like this; Remove the old path, place timber shuttering along the old path sides to the depth of the surrounding area (in other words, make sure the finished height will be the same as the surrounding area) mix the concrete (preferably in a concrete mixer) to a ratio of 4:1:1 (sharp sand, pebbles, cement) pour it in and tamp/level it out using the top of the shuttering as your guide and finally dress a yard brush over the concrete surface gently to give you some grip, finish off the perimeter using a plastering trowel.
Let's go through it stage by stage; First off we need to get rid of that old path, using a shovel coupled with a good wrecking bar lever up and put the old path into builders bags (or hire a small skip) invariably you will find what is termed as 'clinker' underneath the path, it is like volcanic rock bits that have been laid relatively flat in order to make the base for the tarmac. This needs to be removed also, make sure you have a good supply of builders bags! Once the area to be concreted is clear it is time to put some shuttering down; Shuttering is simply soft wood generally measuring 4 inch by 1 inch (100mm by 25mm) I tend to paint it with a treatment prior to fitting it as this ensures it lasts longer, use a good quality preservative (cuprinol or ronseal etc). After the wood has been treated (sealed) you can now proceed with the shuttering; First off you will need some pieces of 2 inch x 8 inch (50mm x 200mm) square for the vertical stays, one end needs to be sharpened as it will have to be driven into the ground using a lump hammer. Now, placing the shuttering on it's side make sure it is touching the edge of the pathway, drive in a stake to hold in in place, now do this for the entire pathway (3 stakes per 1.8 metres or 6 feet), making sure that one side is level with the other, simply place a spirit level across the pathway over the shuttering, if the bubble is off to one side you will have to either chock one side higher or remove more material allowing it to sit lower. The picture you are looking for is a pathway with shuttering on each side level, with this accomplished you can now put the limestone down. I use 10mm limestone for the base as it is soft and porous, now you might be thinking "why soft and porous?", this is because the ground is not solid and as limestone allows some movement the concrete on top will not crack, using a solid base might result in the concrete cracking at some point due to heat/cold expansion/contraction.
This Limestone needs compacting a little, no need to compact it until it is as hard as the concrete, this is simply a base for concrete to sit on, using a thumper (either bought or made from timber) thump the limestone down until it feels firm, ideally it needs to be around 40mm thick. Once this has been done we now have an ideal site for concrete, double check the shuttering for level and adjust where necessary, once you are happy with the base and shuttering it is now time for the concrete!
Using a cement mixer place 4 buckets of sharp sand, 1 bucket of 10-30mm pebbles and 1 bucket of cement into the mixer (doing it this way ensures a perfect mix everytime) allow the contents to mix a little before adding water, I tend to use a waterproofer additive (available at most DIY superstores) in the water, this helps to stop water penetrating the concrete and freeze cracking it over winter. Once the water has been added slowly wait until the mixture is just falling in the mixer, do not make it too wet! Once it is the right consistency i.e. just falling nicely as you watch it, it is time to pour it. Ideally you would be better pouring it into a wheel barrow first and then transport it to the pathway, from here you shovel it where you need it, pouring it straight into the pathway is a bit hit and miss and in my view, wasteful. Either way you are looking to get it in between the shuttering starting at the bottom of the path and working upwards. Make sure it is slightly proud of the shuttering first, start by 'tamping', this is a method whereby you use a piece of 3x3 inch timber slightly longer than the width of the path and using a tapping motion, tap the concrete down until you are on the edge of the shuttering, once you are virtually on the top of the shuttering you an use a sliding motion, this helps to cut the concrete down to the top edge of the shuttering leaving it smooth and level. Keep on doing this until ALL the pathway is complete, now wash out that mixer using a hosepipe and allow it to drain! Grabbing a yard brush drag it across the surface (at right angles to the length) gently, this leaves tiny score marks, these act as a good grip for the traffic that will be using it. The final thing to finish it off is to use a trowel (plasterers trowel) gently run the front edge of the trowel following the edge of the shuttering all the way round, this will leave a nice 4 inch border that really finishes the pathway off.
Points to note; Concrete sets initially within 24 hours but complete strength is not reached for at least 28 days! Once the concrete has dried buy some 'dustproofer and hardener' it is ready mixed and only needs to be poured over the surface using a watering can, this will harden the concrete and make it more resistant to chips or dents. Cover the concrete over using a plastic sheet in direct sunlight, this will stop it drying out too quickly which will stop it reaching total hardness, to do this use some timber driven into the ground and place the sheet over it, try not to let it touch the path. Animals love wet concrete! Don't be surprised to find tiny paw marks on it, especially if you have a cat! Once it has been hardened the path is ready for service, it should give over 20 years of trouble free service with a simple jet wash each year to keep the moss at bay.
Laying a concrete path/driveway
Views 4 Likes Comments Comment
28 February 2010
Have something to share, create your own guide... Write a guide
Explore more guides