Tag Archives: Strawbale Building

Straw bale classroom: Lime render and clay plaster

02 Sep 14
Michelle Gaffaney
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Our straw bale classroom at Castle Hill School is really starting to take shape now!

The walls are up, the roof is on, and it’s time to start covering the walls.

The naked straw walls, before rendering.

Externally, we’re using a lime render to protect the building from the elements.

Lime is often used on straw bale and cob buildings and is a traditional building material. It is particularly suited to our harsh Yorkshire weather, as it has a sponge-lique quality, absorbing rainwater in bad weather, then releasing it, rather than allowing it to soak into the inner wall.

Here’s Arthur, our plasterer, tackling the first coat:

Lime render

Arthur lime rendering

The difference is astounding, and it’s so exciting seeing the classroom start to look more like a ‘real building’!



Internally, we’re using clay – the oldest and simplest building material of all.

Clay is applied to the wall much like regular plaster, except that more coats will be needed. We start with layers of rough clay plaster, mixed with coarse sand to grip tight to the straw walls. Once this has built up, we apply a final layer of fine clay plaster (made using a finer sand) to give a nice smooth finish.

clay plaster


Straw bale course dates announced

09 Apr 14
Michelle Gaffaney
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Help build the new eco-classroom at Castle Hill School, Todmorden

Anyone can do it  •  Learn green building skills  •  Be part of an exciting new community build

We are excited to announce the dates for our upcoming strawbale building course in Todmorden. Whilst the new eco-classroom is still in the planning stage, we are busy preparing to teach a short courses to a small group of participants.

The course will be completely hands-on – you will be learning about strawbale building, cob walls and clay plastering through doing.

Summer 2014 courses in Todmorden

Straw Bale Building: 24-27 July

£220 per course

Please note participants must be aged 16+.

For more details or to book a place please contact info@greenstone-design.co.uk or phone us on 01706 813777

While we hope that lots of local people will get involved in this project, these courses are open to participants everywhere.