DryPak® Speed Set is a carefully selected blend of cements, fly ash, sands and stone designed to set very rapidly without any mixing. It is suitable for bedding fence posts, letter boxes, clothes lines & numerous other non-structural applications. No mixing is required. Simply add to water to achieve a rapid set in just 20 minutes.
Please see below for our step-by-step guide for post erecting; alternatively you can download our printable copy here:
Use the posthole digger or small blade shovel to dig a hole for your post.
To achieve sufficient strength, the depth of the hole should be 25% of the length of the post.
Be sure to account for this when ordering fencing or pergola materials (i.e. if your fence post needs to be 1.8 m high, order a 2.4 m post).
Spray the hole with water, lightly soaking the soil to prevent absorption of the measured water required for the DryPak® Speed Set.
Wait 30 minutes and check if the soil absorbs more water by lightly spraying it again. If so, the use of a plastic liner may be necessary.
It is important that the soil does not readily absorb water or that the hole does not have excess water in it before placing the DryPak® Speed Set, as a specific amount of water is needed to ensure a proper mix.
Once the hole is suitably saturated, place the post in the hole and support it with wooden props or wedge the post into the hole with broken bricks.
Amount of Speed Set to use
As post holes are not always uniform in shape, it is difficult to calculate the exact amount of product required.
Most standard post hole diggers create a hole 200 – 250 mm in diameter.
To calculate the volume of product required, subtract the volume of the buried section of post from the volume of the hole.
- A 500 mm deep hole that is 250 mm in diameter = 25 litres
- A 50 mm square post, buried 500 mm has a volume of 1.25 litres
- Hole volume (25 litres) minus post volume (1.25 litres) = product required (23.75 litres)
- 23.75 litres of wet concrete will require approximately 45 kg of dry product.
Amount of water to use
Using the above table, carefully measure out the exact amount of clean water in a bucket.
It is important that the exact amount of water is used for the amount of dry material required.
Using too much or too little water will effect the concrete and may cause the post to become unsteady.
Placing the Speed Set
Place the bag of DryPak® Speed Set next to the hole and open the corner.
Pour the measured water from the bucket into the hole.
Without delay, pour the required amount of DryPak® Speed Set Concrete into the hole, ensuring an even distribution around the post.
DO NOT MIX – DryPak® Speed Set Concrete is designed not to be mixed and will set in 20-30 minutes.
Using the spirit level, ensure the post is vertical and readjust the supports if necessary.
ALWAYS add DryPak® Speed Set to water.
NEVER add water to DryPak® Speed Set.
Once you are happy with the position of the post, leave it undisturbed for at least 45 minutes before removing any supports.
The top of the concrete will appear to be dry, however water will be absorbed up through the material.
If more than 1 bag of DryPak® Speed Set is required, repeat steps 1 – 5 within five minutes of placing the previous bag.
Do not apply an unbraced load (such as fencing material or pergola roofing) for at least 24 hours. Any lateral force during this curing period may disturb the base and make the post unsteady.
If, after 24 hours, the top of the concrete is still dry, sprinkle the top of the hole with 500 ml of water.