Is Cork Breathable?

Cork is a highly versatile material with a wide range of applications. That spans from the obvious – pinboards, coasters, and wine bottles – to the more obscure, such as iPad covers, shoes, mousemats, or even some woodwind instruments. But more recently, it’s become well known for its use as a thermal insulator.

That’s led to a common query – is cork breathable? It’s a vital consideration, given how important breathability is for insulation, and buildings more generally. To clear things up, this post will answer the very straightforward question about its breathability and discuss why it matters.

The answer is… yes!

Cork is extremely breathable, which allows it to be used to insulate buildings – both externally and internally. This is due to the unique cellular structure of cork, which repels liquid moisture like condensation or rain, while remaining breathable in terms of air, humidity and vapour.

Being breathable means it has the ability to let moisture pass though, as a form of ventilation. If it didn’t do this, moisture would be trapped in the building, leading to all sorts of issues.

Here’s why that matters…

It maintains good ventilation

A lot of moisture is created in homes and public buildings. Our daily activities consist of things that release moisture into the air. For example, taking a shower/bath, doing laundry, making a meal, or just simply breathing. It is essential to have thorough ventilation throughout, so moisture is able to escape and not build up inside the home.

Common forms of ventilation include air bricks and extractor fans in bathrooms and kitchens, plus the option to open windows and doors. However, the latter has to be balanced with the temperature of your home. Nobody wants to leave windows open in winter when they’ve spent so much heating their home all day.

Unfortunately, these conventional ventilation options don’t always suffice. Natural ventilation through the walls is critical for many buildings, which is why it’s vital that cork insulation is breathable.

And reduces chances of damp and mould

Increased amounts of trapped moisture will inevitably lead to issues with your walls and ceilings. The first problem is damp, when moisture in the air is attracted to the coldest parts of your home. Even when they’re heated to a comfortable temperature above 18°C, some houses have cold areas that just don’t warm up. This can create structural issues if left untreated.

But that’s not all. Damp environments provide the perfect breeding ground for mould, which poses its own problems. Like damp, it is a serious eyesore in your home. However, it also poses health risks like respiratory infections because mould releases harmful spores into the air.

Using breathable cork makes homes less likely to become damp and grow mould. Even more so because SprayCork creates a moisture-resistant surface on walls when used internally, meaning condensation can’t settle on it.

Insulation is improved

Using breathable cork will improve the thermal performance of your home. Heat will not be able to pass through your walls and the moisture will not build up.

Overall, good insulation can give you a comfortable temperature with lower energy bills. This will make it easier and cheaper to keep your home warm, minimising the risk of cold spots where damp is most prevalent.

Cork coatings can also absorb up to 38db of noise, offering good sound insulation.

Breathable cork insulation is versatile

Because it’s breathable, cork can be used in all types of buildings, even if their walls are permeable.

Permeable walls are common on older buildings, which are designed to let moisture escape naturally. On the flipside, more modern buildings use impermeable walls with alternative means of ventilation.

A common example of permeability comes in stone walls. Over time, it has become clear that they don’t keep heat in particularly well. However, if they’re insulated using unsuitable, non-breathable materials, the building becomes reliant on alternative sources of ventilation which it simply doesn’t have.

Bonus – it’s a sustainable resource

Using cork is harmless to the environment as it is sourced without any trees having to be felled. The bark is taken from the cork oak tree which regrows each time it is stripped. Carbon dioxide is reduced in the air as oxygen is released when the bark is removed and regrows. So, cork makes breathing easier in the long run, as well as being breathable itself.

3 applications for breathable cork insulation

Is cork insulation breathable? It’s a resounding yes. As a result, it’s ideal for a range of insulative applications…

External walls

One of the most common uses of cork insulation is as a render on external walls. It’s breathable and highly insulative, reducing heat loss by as much as 30%. SprayCork is also flexible for better crack-resistance, highly weatherproof and ultra-stylish with a choice of colours for the outside of your home.

Internal walls

Another popular application of cork is insulation on the inside of homes. Unlike alternative forms of interior insulation, it doesn’t eat away at the size of a room. SprayCork is applied in two thin coats with an overskim of plaster, resulting in a final coating of around 8mm.

Conservatory roofs

Additionally, breathable cork insulation can be used on conservatory roofs. While breathability is less important for this application, it can be transformative for conservatories that get too warm in summer and too cold in winter. A cork coating repels UV rays while insulating the space thermally, creating a more stable, comfortable environment to enjoy all year round.

CorkSol’s sustainable solution to breathable insulation

At CorkSol, we empower customers across the UK with the breathable insulative qualities of cork. Our SprayCork coating can be used on both external and internal walls to improve thermal and acoustic performance. Want to find out more or get a quote from one of our Approved Applicators? Contact our team today on 01484 442420 or email [email protected].