Setting a letterbox post
Read the installation instructions provided by the letterbox manufacturer and then follow these simple steps to use the recommended concrete product to install your new letterbox.
Tools you will need:
- Spirit level
- Tape measure
- Post shovel or long handled shovel
- Measuring jug
- Hose or bucket
- Rod for tamping
Materials you will need:
- Bags of Rapid Set Concrete 20kg
- Letterbox & post
- Drainage material: gravel
- Clean water
Although you can use any product from the Cement Australia concrete range, we recommend Rapid Set Concrete for ease & speed.
Hardens within 15 minutes, ideal for use where the surface won't be left visible
Before you get started
- Read the Hints & Tips section
- Use our simple Calculator to work out how much Rapid Set Concrete you will need for the project.
- 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.
- Rapid Set Concrete will harden in 15 minutes or even faster on a hot day. Be prepared to complete your project quickly. Take the time to read these instructions carefully before getting started.
- Check with Australia Post for any particular restrictions on where you can place a letterbox on your property.
Before you begin any project, please ensure you protect yourself with the following:
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.
- 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 and to assist with holding the letterbox post whilst you add the Rapid Set Concrete.
How to set a post in the ground to hold a letterbox
STEP 1: DIG THE HOLE(S)
If you’re putting your letterbox in a new location, use a post hole digger or long handled shovel to dig your post hole(s) adding 10cm depth to allow for gravel to be placed under the post for drainage. Aim for the letterbox opening to be between 900 mm and 1200 mm above the ground.
Refer to our simple Calculator to work out how much concrete product you will need.
STEP 2: SOAK THE HOLE(S)
STEP 3: POSITION THE LETTERBOX POST
STEP 4: ADD WATER & HALF THE RAPID SET CONCRETE
STEP 5: TAMP WELL & ADD THE REST
Tip: Tamping is essential to remove air pockets and achieves a solidly set letterbox every time.
STEP 6: SLOPE THE SURFACE
STEP 7: ATTACH THE LETTERBOX
Hints & tips
- If the post is made of aluminium or steel, make sure that it has been properly sealed before setting it into the ground using any concrete product. Concrete contains cement which is an alkaline substance and can cause corrosion to uncoated metals.