Is Plasterboard Natural and Breathable? – Can I Just Ask? – Episode 1

Is Plasterboard Natural and Breathable? A Closer Look at an Overlooked Material

In the world of natural and sustainable building, few materials spark as much quiet controversy as plasterboard. It’s a staple of mainstream construction, yet often maligned or dismissed by proponents of “natural” building methods. But is this reputation deserved? Or does plasterboard have more to offer than we give it credit for?

If you’d rather hear Andy and Chris talk through the ideas in this article, you can watch Episode 1 of Can I Just Ask? below. 👇

The Case for Plasterboard

At its core, plasterboard is a simple product: a layer of gypsum encased in paper. Gypsum itself is a natural mineral, mined from the ground and then dried. The paper facing is usually made from recycled content. This means, from a material standpoint, plasterboard ticks several boxes for sustainability and circularity.

Contrary to common belief, plasterboard is also highly vapour permeable. In fact, it can be as breathable—if not more so—than materials typically celebrated in natural building, like lime. Vapour permeability allows moisture to pass through rather than become trapped, helping buildings stay dry and reducing the risk of mould or material decay.

A Question of Context

So why does plasterboard get a bad rap in sustainable circles? Part of the issue lies in misuse. Applying gypsum plaster directly onto masonry, for instance, often leads to problems like blistering or crystallisation—especially in older, uninsulated buildings where walls are cold and highly conductive. In such cases, moisture condenses on the cold surface, is absorbed by the gypsum, and begins to break it down.

But used correctly—as part of a properly specified system—plasterboard performs exceptionally well. When combined with dense, hygroscopic insulation materials like wood fibre, it becomes an effective surface finish that buffers moisture and maintains interior comfort.

Environmental Impact and Fire Safety

From an environmental perspective, plasterboard also holds its own. Its production involves relatively low embodied energy, especially compared to materials like lime, which require the chemical transformation of limestone at extremely high temperatures. Gypsum, by contrast, is dried at temperatures closer to those of a domestic oven.

Fire performance is another strength. Plasterboard is widely tested and rated for fire resistance, something that can be challenging to achieve with plant-based materials typically used in natural building. Its widespread availability and familiarity also mean that it can be installed by mainstream contractors, easing integration into both conventional and alternative building projects.

End-of-Life and Recycling

One often-cited concern is plasterboard’s end-of-life disposal. When sent to landfill, gypsum can react with organic waste to produce hydrogen sulphide—a toxic gas. But this is a problem of waste management, not of the material itself. Gypsum is infinitely recyclable and can be reprocessed into new plasterboard or alternative board products, such as Fermacell, if the right systems are in place.

The Verdict

In summary, plasterboard is a misunderstood material in the natural building world. It’s natural, vapour permeable, fire-safe, low in embodied energy, and recyclable. Like any material, it must be used appropriately—particularly in retrofit situations where thermal bridging and moisture risk are concerns. But when paired with intelligent design and complementary materials, plasterboard can be a reliable and sustainable choice.

Perhaps it’s time we gave plasterboard the credit it deserves—not just as a mainstream convenience, but as a viable component of breathable, natural construction systems.