Sand and cement render is the traditional external coat: a graded sand, cement and lime mix trowelled onto brick or block, built up in coats and floated flat. It is hard-wearing, fire-resistant, cheap in materials and completely unforgiving of bad preparation — which is why so much of our repair work is fixing someone else's cement render.
Done properly, the substrate is cleaned and keyed, the mix is batched consistently across the whole facade so the colour does not band, and each coat is allowed to take up before the next goes on. Rushing the cure is the single most common cause of the map cracking you see on cheap render jobs.
Cement render can be left as the finished surface, painted, or used as the base for an acrylic or texture top coat. On a full facade we will usually recommend a cement base with an acrylic finish so you get the strength of one and the flexibility of the other.
Best suited to
- Brick and blockwork that needs a solid, straight base
- Walls that will be painted or top-coated later
- Repair and patch work matched into existing cement render
- Fences, retaining walls, garages and outbuildings
When we'd steer you elsewhere
- Solid-brick heritage walls that need to stay breathable
- Substrates with active rising damp or salt attack
Assessment before action
When cement render is the right system
Appropriate applications
- Brick or concrete block that needs to be straightened and levelled
- Fences, garages and robust masonry surfaces
- A mineral base that will later receive paint, acrylic texture or a membrane
What commonly causes failure
- Poor keying on smooth brick, paint or dusty blockwork
- Mixes that are too rich, too wet or inconsistent between batches
- Coats applied too thickly or without time to take up
- Rapid drying in hot wind, or ongoing salt and moisture movement through the wall
Signs the wall needs attention
- Drummy areas that sound hollow when tapped
- Map cracking, edge lifting or sections falling away
- White salt deposits, dark damp lines or paint blistering
- Rust staining around unprotected metal beads
Photos are useful for a first look, but bond, moisture and movement need to be assessed at the wall. If you can see one of these signs, send close-up and full-elevation photos with your quote request so we can advise whether an inspection is the next step.
Repair or replacement
Keep sound work. Replace failed work.
Repair makes sense when
Sound surrounding render can stay when failed areas are isolated and the new patch can be keyed into firm edges.
Replacement is safer when
If hollow areas dominate an elevation, the bond is unreliable throughout and stripping that elevation is normally better value than repeated patches.
| Option | Best suited to | Main consideration |
|---|---|---|
| Patch repair | A few firm-edged drummy areas | Retains sound work; finish often needs a full-elevation recoat |
| Full re-render | Widespread debonding or badly uneven work | Higher initial cost but restores a reliable base |
| Acrylic overcoat | Sound cement base needing colour and flexibility | Does not stabilise hollow render underneath |
How we do it
The cement render process
Key and clean
Smooth or painted brick is keyed or bonded so the mix has something to grip.
Scratch coat
First coat applied and scratch-keyed, then allowed to take up rather than being rushed.
Float coat
Second coat ruled off against screeds and floated flat — this is where a wall is made straight.
Finish
Sponge, wood float or steel finish as specified, or left ready for a texture or acrylic top coat.
Cure
Kept damp in hot weather so the mix cures rather than dries out and crazes.
Technical detail
Materials, application and curing
Materials in the system
Washed graded render sand, general-purpose or masonry cement, measured lime or plasticiser where the specification permits, clean water, bonding agents, galvanised or PVC beads and reinforcement mesh at nominated junctions.
Application method
The wall is dampened to control suction, then scratch and float coats are built to the required plane. Screeds establish line and level; the final surface is wood-floated, sponged or steel-finished for its next coating.
Curing and protection
Cement render gains strength by hydration. It must be protected from fast moisture loss, lightly mist-cured when conditions demand it and allowed about 28 days before conventional painting so residual moisture and alkalinity can dissipate.
Colour and texture matching
Unpainted cement patches are matched by sand grade, binder ratio and finishing technique, but new work will initially read lighter. Where appearance matters, the repaired elevation is normally painted or texture-coated after cure.
Lifespan and maintenance
Well-bonded cement render on stable, dry masonry can last 20–40 years. Paint cycles, crack treatment and keeping water out of wall tops and bases determine whether it reaches the upper end of that range.
Practical care
- Keep garden beds and paving below weep and damp-course levels
- Maintain paint or membrane before it becomes chalky
- Seal cracks after confirming they are no longer moving
- Check parapets, copings and fence caps for water entry
Warranty information
Warranty depends on the masonry being stable, dry and suitable for the nominated build-up. The quote identifies coat thickness, finish and exclusions; movement, rising damp, salt attack and premature painting cannot be warranted as render defects.
A site-specific written quote is the source of truth for product, preparation, access, finish, exclusions and the warranty offered on your project.
Request a written quoteBuilt for local conditions
Melbourne walls are not all the same
Cement work in Melbourne needs weather-aware sequencing. Hot northerlies can dry a coat before it cures, while cold winter walls extend set times; both conditions change how we dampen, protect and schedule each elevation.
View Melbourne service areasWorkmanship you can check
- Batch proportions kept consistent across the elevation
- Suction and bond controlled before the first coat
- Corners, screeds and planes checked in raking light
- Curing and paint-ready dates stated at handover
With more than 20 years in the trade, we explain the substrate, proposed build-up and likely limitations before work starts—not after a crack or colour variation appears.
Common questions
Cement render questions
How long before I can paint new cement render?
Give it a minimum of 28 days to cure. Painting early traps moisture and alkalinity in the coat, which is what causes bubbling and patchy colour a year later.
Why is my cement render drummy?
Drummy render means the bond to the brick has let go — usually poor keying, a dirty substrate, or render applied over old paint. It has to be cut out and re-rendered; patching over it just moves the problem.
Is cement render cheaper than acrylic?
The materials are cheaper, but it is more labour-intensive and usually needs painting afterwards. On a whole facade the finished cost is often close.
Can cement render go straight over painted brick?
Not reliably without preparation. The paint must be proven sound and mechanically keyed or covered with a compatible bonding system; loose or chalky coatings must be removed.
Does every crack mean the render has failed?
No. Fine shrinkage cracks can remain well bonded, while a crack accompanied by a hollow sound signals debonding. The cause and bond condition decide the repair.
Other systems we apply
Acrylic Rendering
Pre-coloured, polymer-modified render that flexes with the building instead of fighting it.
Texture Coating & Stucco
Rollcoat, sponge, fine sand and rough cast — matched off an existing wall so the join disappears.
Heritage & Lime Render
Breathable lime coats for solid-brick period homes, where modern sealed render traps moisture and blows the masonry apart from inside.
Related repair services
Working out a budget? See our Melbourne rendering cost guide, or find your suburb.
Get a quote for cement render
Send through the details and a couple of photos and we will book a site visit and come back with a written itemised quote.