Category Archives: Landscaping

Very simple and inexpensive landscaping ideas for the DIY people out there, many projects are easy enough and safe for your children to do, and you will reap the rewards for it.

How to lay a concrete garden kerb yourself. D.I.Y.

You will need to have the materials and tools below to produce your own concrete kerb..

  • Flexible timber for the form work. (In Australia, Jarrah timber strips are easily obtained.)
  • String
  • Coarse sand.
  • Bags of Cement.
  • Pegs, either timber or steel to hold form work in place.
  • Wheel barrow.
  • Shovel and spade.
  • Cement Edge Trowel (or similar)

(For Kerbing, the Sand Cement ratio is, 1 bag cement to 16 shovels of coarse sand. this will produce approximately 10 linear metres at 90mm x 150mm

NOTE: 10 bags builders cement and I cubic metre of sand, will produce approximately 50 linear metres of concrete kerb at 150 x 90mm.

IMPORTANT: Wash hands if you come into contact with wet cement. (The lime in cement it will eat away any skin that comes in contact with it)

Next:

You will need to remove the grass under the area you intend to lay your kerbing.

A sand or crushed rock base is then laid. (Its important to get your levels correct at this stage.)

Set your timber form work in place, and hold it in position with the pegs hammered into the ground. 150 x 90mm.

 

  • You can use a string line to get your lines and levels set.
  • For curves a Stake driven into the ground with a string attached will suffice for any circles or arcs you may need.

NOTE: To get your timber to bend easily, cut a series of vertical lines in it, this will weaken the timber strip in this area and make it easy to bend without breaking.

Set you timber in place with pegs at your desired width.

  • example:  90 x 150mm

Mix your concrete with a concrete mixer or in a wheelbarrow. and shovel it into your timber form work.

Allow a few minutes for the concrete to harden, then use a Cement Edge Trowel to give the kerb a smooth finish.
P.S. You can throw colour hardener on top of your concrete kerb, then trowel it into your concrete surface to produce a nice coloured kerb.

Cement Edge Trowel
You can also colour the garden kerb with Concrete Colour Sealer or a Concrete Paint.

Allow 1 day before removing form work.

IMPORTANT: Cut expansion joints approximately 1 metre apart to control cracking.

How long will a concrete kerb take to dry before I can use my mower?

How long will it normally take for concrete kerbs take to dry
Concrete normally dries at fairly consistent rates.

Note: The ambient Temperature is a factor to take into consideration when calculating drying times

Concrete doesn’t gain strength by drying, but by “curing” which it does for the period while it remains damp after laying.

A 100mm thick kerb take approximately:
1 day to achieve around 30% of its full strength.
At 2 Days it passes the 50% mark.
And at 3 Days 75% has been achieved.
It takes concrete approximately 30 Days to reach 99% of its final compression strength.
The thickness of the concrete will of cause affect the curing times.
I.E. The thicker the longer it will take.

Its a good idea is to keep the concrete damp while it cures, you can place a sheet of polythene over it. You can also spray water on it with a hose if you want to.

Note; If you can keep the concrete damp for a week or more, it will have a higher compression strength.

diy concrete kerb

Protect the concrete from hot sun for the first day (in some countries they don’t lay concrete until the afternoon to avoid the hot mid-day sun which causes cracking and dusty/flaky surfaces).