Breathable Masonry & Render Paint

Breathable masonry paint and render paint for exterior walls

Choose the right exterior paint for render, brick and insulated facades. We stock breathable silicone masonry paint and durable acrylic exterior paint in 10 L tubs, together with the primers you need for a long-lasting finish. Both paints are designed for facades - from rendered walls and K rend-style silicone renders to brickwork and external wall insulation systems.

Silicone vs acrylic masonry paint

The two main types of exterior facade paint behave very differently. The right choice depends on the wall you are painting and how much moisture needs to escape from it.

What is breathable masonry paint and why does it matter?

Breathable (vapour-permeable) masonry paint lets water vapour pass out of the wall while stopping rain from getting in. This matters most on older solid-wall houses, rendered facades and external wall insulation systems, where moisture inside the wall needs a way out. A paint that seals the surface can trap that moisture behind the paint film. Over time this leads to blistering, flaking, damp patches and frost damage. Silicone masonry paint combines high breathability with a water-repellent surface, which is why it is the preferred choice for render and solid masonry.

The best paint for render

The right render paint depends on the render underneath:

• Silicone render - is coloured through and normally does not need painting. To refresh or change the colour, use a silicone paint such as IS73 to keep the surface breathable and water-repellent. See our silicone render guide.
• Acrylic render - can be painted with acrylic or silicone exterior paint.
• Sand and cement render - use a breathable silicone masonry paint. Let new render cure fully before painting, typically around four weeks.
• External wall insulation - use silicone paint over the finished render to keep the system vapour-permeable.

Thin-coat silicone renders are often a better long-term choice than painting a facade, because the colour is in the render itself.

How much masonry paint do you need?

Coverage depends on the texture and absorbency of the surface and the number of coats. Rough render and porous brick use more paint. Allow for two coats on most surfaces.

How to paint exterior walls

1. Check the weather - paint in dry conditions, above around 5°C, out of strong direct sun and not when rain or frost is forecast.
2. Prepare the surface - remove loose and flaking paint, brush off dust and dirt and treat any mould or algae.
3. Repair - fill cracks and let repairs dry fully.
4. Prime - apply a primer to porous, dusty or patched areas so the paint absorbs evenly.
5. Apply two coats - by brush, roller or sprayer, following the drying time on the tub between coats.

You will find brushes and rollers and tapes and protection in our painting and decorating range.

Frequently asked questions

Is masonry paint breathable?

Not all of it. Silicone masonry paints are highly breathable, while many acrylic and standard masonry paints are less vapour-permeable. For solid walls, render and external wall insulation, choose a silicone-based breathable masonry paint.

What is the difference between silicone and acrylic masonry paint?

Silicone masonry paint is more breathable and more water-repellent, so it lasts longer on render and solid walls. Acrylic exterior paint forms a tough, flexible film and costs less, but is less vapour-permeable.

Can you paint silicone render?

Yes, but it is rarely necessary because silicone render is coloured through. To change the colour, use a silicone paint so the surface stays breathable and water-repellent.

How long after rendering can I paint?

Sand and cement render should normally cure for around four weeks before painting. Always follow the render manufacturer's guidance.

Will masonry paint stop damp?

A water-repellent silicone paint helps protect walls from driving rain, but no paint will cure rising damp, leaks or failed render. Find and fix the cause of damp first, then choose a breathable paint so the wall can dry out.

How much paint do I need for a house?

Measure the wall area, subtract windows and doors, and allow for two coats. As a guide, a 10 L tub of IS73 silicone paint covers around 75 m² and a 10 L tub of IS71 acrylic paint around 45 m², depending on the surface.

Can I collect exterior paint in person?

Yes. Collect from our store at 17 White Lion Road, Amersham, HP7 9HZ, or choose UK delivery at checkout.