General Purpose Cement
The binder. You bring the sand.
Cockburn Grey General Purpose Cement is a raw AS3972 Type GP binder in 20kg and 40kg bags, made in Western Australia. You supply the sand, the aggregate and the water. It goes into brickwork, footings, paths, render and concrete repairs, and into M4, M3 and M2 mortars when blended with sand and Hylime.
Or call the yard on (08) 9434 2290
Real stock, not a swatch. Blended products vary a little batch to batch, so treat these as a guide rather than an exact colour match.
General Purpose Cement details
General Purpose Cement at a glance
- Product type
- Raw binder, not a pre-mix
- Brand
- Cockburn Cement
- Classification
- AS3972 Type GP
- Sizes
- 20kg, also 40kg
- Made in
- Western Australia
- Blends to
- M4, M3 and M2 mortar
What General Purpose Cement suits
What can you use General Purpose Cement for?
Brick and block mortar
Blended with brickies sand and Hylime. This is the route to take when you need to choose the mortar class rather than accept the one in a pre-blended bag.
Footings, paths and driveways
With concreting sand and aggregate. Unlike the brickies blends, GP cement is a concrete cement and belongs in load-bearing work.
Render and floor screeds
Grey finish. Where the render is going to be painted or is out of sight, there is no reason to pay for the cream or the white.
Concrete repairs
Patching a step, a path or a cracked slab. A bag goes a long way on repair work and it keeps for a good while if it stays dry.
Which bag, and how it is sold
Sold by the bag, not by the metre
Cement is bought by weight and used by ratio, so the useful question is not how many cubic metres but which bag and how many of them.
How much sand and aggregate goes with each bag is on the pack, and it changes with the job. We would rather send you to the bag or the counter than print a number here that is right for one pour and wrong for the next.
| Pack | Weight | What it suits |
|---|---|---|
| Grey GP cement | 20kg bag | Hand mixing, repairs, anything you are carrying. The standard bag. |
| Grey GP cement | 40kg bag | Volume work, where you are getting through bags and a mixer is running. |
| Mix ratio | Printed on the bag | Varies with the job. Ask at the counter if the work is unusual. |
Wet cement and lime burn skin, and the burns are delayed so people often do not notice at the time. The dry dust contains crystalline silica. Gloves, eye protection and a P2 mask, every time.
General Purpose Cement in Perth
Perth's coast, and why the raw bag still sells
The masonry code does not allow M3 mortar for external brickwork within a kilometre of the coast — it calls for M4 there instead. A good deal of Perth sits inside that band, and it is not always obvious from the street which side of the line a job is on.
The pre-blended brickies bags are M3, which is exactly why raw cement is still a bricklayer's bag. Cement, brickies sand and Hylime blends to M4, M3 or M2, so on a coastal job it is the one that gives you the choice. If you are not sure how far out you are, ask us before you order rather than after you have laid a wall.
Why General Purpose Cement
Why choose General Purpose Cement?
The classification most work is specified against
AS3972 Type GP. If a plan or an engineer names a cement type, this is nearly always the one it names.
It is the bag that can make M4
The pre-blended brickies bags are M3, and the masonry code does not allow M3 for external brickwork within a kilometre of the coast. Cement, sand and Hylime blends to M4.
Made in Western Australia
Cockburn manufacture it here, so it is not sitting on a boat and it does not change character between batches.
Two sizes
20kg for hand work and anything you are carrying up a ladder, 40kg when you are getting through volume.
Getting General Purpose Cement home
How to get General Purpose Cement
Collect from the yard
Open seven days at 222 Barrington St, Bibra Lake. The loader puts it straight into your trailer or ute, and someone will tell you whether what you have brought will carry the load.
Borrow one of our trailers free for two hours to get your load home. No charge, no bond.
Have it delivered
Across Perth's southern suburbs, seven days. For a quote we need the address, how much you need, and anything awkward about access — tight driveways, low branches and side access all change which truck we send. Confirm the current cost when you order.
Formats
- 20kg bags
- 40kg bags
- Single bags or by the pallet
Using General Purpose Cement
How to use General Purpose Cement
Settle the mix before you open anything
Follow the ratio printed on the bag, or bring the job to the counter. We do not publish one here because the right one depends on what you are pouring, and a wrong ratio in a footing is not something anybody finds out about for a year.
Measure by the bucket, not the shovel
A shovel of damp sand and a shovel of dry sand are not the same amount of sand. Mortar and concrete strength follow the ratio, and the ratio only means something if you measure it.
Mix dry first, then bring the water in
Get the cement right through the sand before any water goes near it. Add water to a dry-mixed batch and you get a consistent colour and no lumps to chase.
Keep it damp while it cures
Cement gains strength over days and needs moisture to do it. Work left to dry out in the sun through a Perth summer is measurably weaker than the same mix kept covered and damp.
When to choose something else
When it is the wrong product
- It is a binder, not a mix. There is no sand and no stone in the bag, so on its own it does not make anything.
- No mix ratio is published here, deliberately. The bag carries it and the counter will talk it through — the right one depends on the job, and a guessed ratio is worse than asking.
- If you are laying bricks and do not need to choose the class, the pre-blended bag is easier and the lime dose will be right every time.
- Wet cement and lime burn skin, and the burns are delayed so people often do not notice at the time. The dry dust contains crystalline silica. Gloves, eye protection and a P2 mask, every time.
Customer reviews
What people say
General Purpose Cement questions
General Purpose Cement FAQs
Goes with General Purpose Cement
Other products you may need
What goes with it
The sand and the lime that turn a bag of cement into mortar.
The pre-blended shortcut
Cement and lime already proportioned.
If the finish should not be grey
Cream and true white, same classification.
Guides for general purpose cement
Planning your project
General Purpose Cement quote
Need General Purpose Cement for your project?
Send us the quantity you need, your suburb, and whether you would like to collect it or have it delivered. If you are not sure how much, put your measurements into the calculator above and we will check it for you.
Or ring the yard on (08) 9434 2290
222 Barrington St, Bibra Lake WA 6163 · Open 7 days
Use the calculator above and the amount lands in the message for you.