External cork coating for tired, cracked render.

Is your render making the house look neglected?

If you have put time and money into the inside of your home and the outside still looks tired, you are not alone. Faded colour, patchy repairs, hairline cracks and peeling paint are what most people notice every time they pull up outside.

The people who ask me about external cork coating usually fall into three groups:

• Homeowners who want the outside to match the inside. The windows are new, the garden is done, but the render lets it all down.
• People getting ready to sell. Photos and first impressions at viewings matter. A clean, even finish improves how the house presents, although any effect on the sale price depends on the property and the market.
• People fed up with repainting. They have paid for scaffolding, preparation and masonry paint more than once and want to know whether a more durable finish is worth spending more on.

What is external cork coating?

It is a coating made from cork granules and binders, sprayed onto a prepared wall to form a continuous, textured skin a few millimetres thick. It replaces the endless layers of masonry paint rather than adding another one.

I use systems supplied through SprayCork UK, including the ReveCork range. It comes in different texture grades, from fine to more open, so the finish can suit a 1930s semi, a modern house or a rendered extension. Colours are chosen from the supplier's range, and I bring samples so you can see them against your brick, roof and window frames in daylight.

What are the benefits over painting or re-rendering?

The main benefits are flexibility, breathability, weather resistance and fewer repeat maintenance bills. Here is how it compares, honestly.

• Flexibility. The coating can take normal small movements, helping stop fine cracks from reappearing. It does not cure structural movement, so bigger cracks get assessed first.
• Breathability. Water vapour can pass through, which matters on older solid walls, though the whole wall still decides how it dries.
• Weather and colour. The system is designed for rain, sun and frost, and the supplier states the colour holds rather than fading quickly.
• A slightly warmer wall. Cork slows heat a little, but a thin coating is not external wall insulation and I won't claim big savings.

Why does preparation matter so much?

Because a coating can only be as good as what it is stuck to. The supplier is clear that existing render and paint must be sound and properly prepared, and I agree.

An ugly wall can still have perfectly sound render underneath. At the survey I tap and check the render for hollow areas, look at the cracks and ask why they are there, and check gutters, sills, copings and the ground level for moisture problems. Then I explain which areas can stay, what needs repairing and why that is in the quote.

• Loose, hollow or blown render is cut out and made good.
• Cracks are opened and filled to suit their cause.
• Algae, dirt and failing paint are removed.
• The surface is primed to the supplier's specification.

This is often the biggest part of the price, and it is the part you won't see once the job is done.

What is it like having the work done?

Most of the disruption is scaffolding and masking, and you can stay in the house throughout. Windows, doors, paths and plants are covered, and overspray is controlled carefully.

You get a pre-start information guide, clear updates as the work progresses, and a tidy site at the end of each day. You can read more about how a job runs from first visit to handover.

How long does it last, and is there a guarantee?

The supplier states a 15-year guarantee on the coating when it is applied to their specification by an approved applicator. The exact guarantee for your job, what it covers and any conditions are written into your quote before you commit.

I follow the supplier's method closely, keep you updated as the work progresses, and set everything out in writing so you know exactly what you are getting. Visit the spray cork overview for the other ways I use cork.