Selleys No More Cracks Exterior Brick & Render

What is Selleys No More Cracks Exterior Brick & Render, and where should you use it?

Selleys No More Cracks Exterior Brick & Render is a ready to use, water based filler that dries to a durable render texture finish. It repairs deep, wide cracks, chips, holes and small shallow surface imperfections on exterior masonry — bricks, concrete and cement render.

The feature that sets it apart from a general-purpose filler is that it can be finished two ways. You can tool it to a render texture so the repair reads as part of the surrounding wall, or you can sand it to a smooth finish. On a rendered wall, that choice is the difference between an invisible repair and an obvious smooth patch in a textured surface, and it is decided while the filler is still workable, not afterwards.

Technical specification

Property	Typical result
Technology	Water based
Colour	Grey
Sanding / painting time	2–3 hours for a 2–3 mm application
Packaging	500 g tub
Paint compatibility	Water based and oil based paints
Minimum application temperature	5°C

These are indicative data from the product's technical data sheet only, and are not intended for the preparation of specifications.

What the drying times mean in practice

The headline figure is 2–3 hours for a 2–3 mm application, and it is a thin-fill number. Selleys attaches four separate conditions that lengthen it: humidity, deeper applications, colder weather, and painting with oil based paints.

That last one catches people out. The filler can be painted with either water based or oil based paints, but oil based paints require longer drying time first. If your exterior finish is an oil based system, the 2–3 hour figure is not your schedule.

For deeper repairs there is a separate rule that overrides the drying time entirely: apply in 10 mm layers, letting each layer dry before the next. A deep crack in render is not a matter of pushing in more filler and waiting proportionally longer. A thick single fill dries at the surface while the core stays wet, and the result shrinks and cracks. Ten millimetres at a time is slower on the day and quicker over the job.

Protect the repair from rain until it is dry. This is a water based filler on an exterior wall — until it has dried, rain will damage it. Look at the forecast before you start, not after.

Where to use it

This filler is for exterior masonry surfaces:

• Bricks
• Concrete
• Cement render

It handles the full range of damage on those surfaces — deep and wide cracks, chips, holes, and small shallow imperfections — which is why it comes in a 500 g tub rather than the small tubs used for fine interior work.

The colour is grey, which suits unpainted concrete and cement render better than a white interior filler would, though the repair is still intended to be painted for a finished result. Selleys has a general guide to filling cracks in masonry walls, and the other options for exterior masonry — including the cement based Exterior Powder Filler — are on the wall filler page.

How to apply it

1. Make sure the surface is clean and dry, with no loose powdery material. On old render this usually means brushing out the crack — the loose material inside a crack is the reason repairs fail early.
2. Use a filling blade or trowel to press the filler into the hole, and tool it to a feathered edge. The feathered edge is what makes a repair disappear; a repair with a hard boundary line will always show through paint.
3. For thin applications of 2–3 mm, allow 2–3 hours to dry, depending on humidity.
4. For deeper holes, apply in 10 mm layers, allowing each layer to dry before applying the next.
5. Decide your finish. Tool it to a render texture to match the surrounding wall, or sand the surface after drying for a smoother texture.
6. Protect it from rain until dry.
7. Paint when ready. Water based or oil based paints can both be used — allow longer drying times before oil based paints, for deeper applications, or in colder weather. Apply an undercoat before your top coat for best results.

Matching the texture

Getting a repair to disappear on a rendered wall is a texture problem more than a colour problem, because the paint takes care of colour. A smooth patch in a textured wall catches the light differently along its whole edge and stays visible after painting.

The tooling stage is where this is won. Work the surface of the filler to match the render around it while it is still workable, and feather the edge out rather than stopping it abruptly. If you want the opposite — a smooth finish, perhaps on a smooth-rendered or concrete surface — Selleys' instruction is to sand the surface after it has dried.

Painting the repair

The filler can be painted over with water based or oil based paints, which is more flexibility than many exterior fillers offer — you are not forced to match your existing paint system to the filler. Selleys recommends applying an undercoat before your top coat for best results.

The one thing to adjust for is timing. Oil based paints require longer drying beforehand, as do deeper applications and colder weather, and those three conditions stack. A deep repair, painted in an oil based system, in winter, is not a 2–3 hour proposition — give it the day.

Limitations — where Exterior Brick & Render should not be used

• Do not use below 5°C. This is the manufacturer's stated limitation. A water based filler applied in the cold does not dry as intended.
• Where movement occurs, use Selleys Paint Over Sealant instead. This is the important one for masonry. A rigid filler cannot accommodate a moving joint, and a crack that is still moving will simply reappear through the repair. Control joints, junctions between different materials, and cracks that have opened progressively are all signs of movement rather than a static defect.

The practical test before you fill a crack in render is whether the crack is finished moving. Filling a live crack with a rigid product produces a repair that fails and takes some of the render with it. If in doubt, treat it as a moving joint.

Clean up and storage

Clean up: clean tools and hands with water before the filler dries. Being water based, it washes off easily while wet and has to be scraped or sanded once dry.

Storage: close the lid tightly after use and store in a cool, dry place. A 500 g tub usually outlasts one job, so a properly sealed lid is worth the few seconds.

Hazard classification

Classified as hazardous under Safe Work Australia GHS 7, with the signal word Warning.

• Sensitisation — Skin — Category 1. H317: may cause an allergic skin reaction.

It is not classified as Dangerous Goods for transport by road, rail, sea or air. No composition breakdown that can be attributed to this product with confidence is available here, so none is reproduced.

One classification, and it is the one people underestimate. A skin sensitiser is not the same thing as an irritant. Irritation is local and it stops when the contact stops; sensitisation is the immune system learning to react to the material, it is generally permanent once acquired, and from then on a far smaller exposure will set off a reaction than the one that caused it. It develops through repeated ordinary contact, which is why a product used for an hour at a time over a weekend is a more realistic route to it than a single splash.

This one is a texture-matching filler for exterior masonry, so the technique the page describes — working the surface to match a render texture, often over a large patch — involves more hand contact for longer than a small interior fill does. Gloves, and washing off what gets on you rather than letting it dry on your skin, are the whole of the answer.

The label precautions also ask you to avoid breathing dust, to keep contaminated work clothing out of the workplace, and to wear protective gloves and eye/face protection. The dust warning is aimed at the stage after the repair has dried, when it is sanded back — wear a dust mask for that, particularly on exterior work where you may be sanding above head height.

Protection

• Gloves — nitrile rubber, suggested by the SDS as suitable for intermittent contact, with the user making the final assessment.
• Eye protection — protective clothing including eye/face protection.
• Dust mask — when sanding the dried repair.
• Ventilation — avoid breathing dust; ensure air movement where dust could accumulate.
• Wash hands before eating, drinking or smoking. Wash contaminated clothing and protective equipment before storing or reusing.

First aid

Exposure	What to do
Eyes	Wash out immediately with water, holding the eyelids open, and keep rinsing. In all cases of eye contamination it is a sensible precaution to seek medical advice.
Skin	Wash with plenty of water and soap. If skin irritation or a rash occurs — including some hours later — get medical advice or attention, as that may indicate sensitisation rather than irritation.
Inhalation	Move the person to fresh air, keep them warm and at rest until recovered. Seek medical advice if effects persist.
Swallowed	Rinse the mouth with water. Do not induce vomiting. Give a glass of water to drink and seek medical advice. Never give anything by mouth to an unconscious person.

If poisoning occurs, contact a doctor or the Poisons Information Centre — 131 126 in Australia, 0800 764 766 in New Zealand — with the container to hand. Selleys emergency line: 1800 220 770 in Australia, 0800 220 770 in New Zealand.

Common questions about Selleys No More Cracks Exterior Brick & Render

How long does it take to dry?

2–3 hours for a 2–3 mm application, depending on humidity. Deeper applications, colder weather and oil based topcoats all require longer.

How do I fill a deep crack or hole?

In 10 mm layers, letting each layer dry before applying the next.

What surfaces is it for?

Exterior masonry — bricks, concrete and cement render.

What colour is it?

Grey.

Can I paint over it?

Yes, with water based or oil based paints. Allow longer drying before oil based paints, and apply an undercoat before your top coat.

Can I match the render texture?

Yes. It can be tooled to a render texture while workable, or sanded to a smooth finish after drying.

What if it rains?

Protect the repair from rain until it is dry.

What size does it come in?

A 500 g tub.

Can I use it in winter?

Not below 5°C, and allow longer drying times in colder weather.

What if the crack is still moving?

Where movement occurs, use Selleys Paint Over Sealant rather than a rigid filler.

Do I need to prepare the surface?

Yes — clean and dry, with no loose powdery material.

How do I clean my tools?

With water, before the filler dries.

How do I get the repair to feather out?

Tool the filler to a feathered edge with the blade or trowel as you apply it. Feathering at the wet stage is far easier than sanding a hard edge back afterwards.