Tools you will need:
- Spirit level
- Tape measure
- String line
- Post hole digger or long handled shovel
- Shovel
- Measuring jug
- Hose or bucket
- Wheelbarrow
- Spray marker paint
- Rod for tamping
- Trowel
Using stirrups or uprights to support a post out of the ground is a great way to provide longevity for your fence or structure as the wooden post is less likely to suffer any rot.
If you are setting uprights or stirrups to install a pergola post or posts to support a roof structure please refer to the pergola manufacturer to ensure bagged concrete mix is appropriate. If a defined strength of concrete is required then its time to have pre-mixed concrete delivered from a ready mixed concrete company.
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Materials you will need:
- Bags of Concrete Mix 20kg
- Uprights or stirrups
- Fence posts
- Clean water
Recommended products
Although you can use any product from the Cement Australia concrete range, we recommend Cement Australia's Concrete Mix.
For increased strength & durability we recommend using Cement Australia's Extra Strength.
Designed to deliver twice the strength of a standard concrete mix
Quality product designed for small projects
Before you get started
- Use the Calculator to estimate how many 20kg bags you will need
- Read the Hints & Tips section
- Carefully read the installation instructions supplied by the manufacturer of any upright products.
- Ensure you have any relevant approvals or permits. Ensure there are no pipes or services below the ground; contact Dial Before You Dig on 1100 or via their website www.1100.com.au for advice on the locations of submerged pipes and cables.
Safety
Before you begin any project, please ensure you protect yourself with the following:
Boots
Face mask
Gloves
Googles
Long pants & sleeves
Team lift
Look after yourself properly
- Protect your skin and eyes. Cement based products are alkaline and can cause burns to exposed skin or eyes.
- When working outdoors, be SunSmart - Slip on some sun-protective clothing – Slop on sunscreen - Slap on a hat - Seek shade - Slide on some sunglasses.
- Use our simple Calculator to work out how much Concrete Mix product you will need for your project.
- All 20kg bags of cement products require 2 people to lift them safely. Always follow safe lifting procedures to avoid injury. So you will need a friend to help you handle the 20kg bags.
HOW TO SET AN UPRIGHT OR STIRRUP USING CONCRETE MIX
1
MARK OUT THE UPRIGHT POSITIONS
Use a tape measure, stakes, a string line and some spray marker paint to work out the correct locations for your holes.
2
DIG YOUR HOLE(S)
Use a post hole digger or long handled shovel to dig your hole(s).
Refer to our simple Calculator to work out how much concrete product you will need.
3
SOAK THE HOLE(S)
Pre-soak the hole thoroughly with clean water and allow the water to drain into the soil.
4
MIX CONCRETE & WATER
In a non-porous vessel, such as a wheelbarrow, add the Concrete Mix no more than 2 bags at a time. Add exactly the amount of clean water instructed on the back of the packaging per bag of Concrete Mix and mix thoroughly remembering that excess water ruins good concrete.
Tip
Ensure you check the back of the packaging for correct water quantity. Using Extra Strength Concrete Mix will have a different water mix ratio.
see how to mix concrete to the right consistency
5
ADD CONCRETE & TAMP WELL
Fill your hole to approximately 25% depth with concrete. Position your upright in the centre of the hole pushing it into the concrete very slightly, ensuring that it is set to the correct depth based on the required height of the timber you will be attaching to the upright. Add the remaining amount of the mixed concrete to the hole, filling the hole to just above ground level. Tamp the product around the upright using a rod to remove any air pockets. Should you need more concrete for the hole, immediately repeat the process with another bag.
Tip
Tamping is essential to remove air pockets and achieve a solidly set upright every time.
6
SLOPE THE SURFACE
Heap the surface of the concrete to create a rounded crown around the upright so any surface water flows away from the upright.
7
ALLOW CONCRETE TO SET
Allow the concrete to harden for a minimum of 7 days before attaching any posts to the upright.
Tip
If using Extra Strength Concrete Mix, posts can be attached to uprights in 5 hours.
Hints & tips
- The ambient temperature can affect the setting times of all types of concrete. If the temperature is less than 10oC, wait until the day becomes warmer and if its over 35oC then postpone the job until it is cooler.
- If a particular job calls for a specified strength of concrete i.e. 20 MPa, then its time to call in the experts and have premixed concrete delivered from a ready mixed concrete company – it’s the only way to guarantee the structural strength in the concrete. Megapascals (MPa) is the common unit for indicating the compressive strength of concrete.