The center for sustainable building of the province organised a workshop strawbale building at Kamp C in Westerlo. Casa Calida, the non profit organisation of our preferred architect, took care of the practical part. We already saw some of his strawbale constructions, but we’ve never really built a strawbale wall. So we definitely need to check that out. Just to be sure that we’re up to the task.
A brief overview:
The workshop started with the theoretical part where Maarten of Kamp C, put the benefits of strawbale construction up front:
- Affordable (a strawbale costs about 1,5 to 2 euros).
- This method uses sustainable (renewable) resources.
- Straw provides very good insulation.
- Earth plaster is healthy and controls humidity excellently.
A few things to consider:
- Fire resistence: tests in Germany showed that strawbale wrapped in earthen plaster will resist fire for over ninety minutes. Even better than traditional bricks. All strawbale houses in Belgium got a normal fire insurance policy.
- Rodents: straw is waste, not food. Rodents will never eat straw. In fact they don’t even like the smell of it. And if the bales are packed tightly, small animals won’t even make warm holes in it. Just make sure you plaster very well.
- Humidity: wet straw (more than 15% humidity) will start to decay. So be sure to use dry straw. Once the plaster finish is applied the straw will be dry and it won’t decay.
After a look at the demonstration building (by architect M. Depreeuw) at the premises of Kamp C we all went to look at a strwabale construction site nearby (Architect P. Vos). The techniques of both architects are pretty different.
P. Vos uses a wooden construction that carries the load of the roof. So the strawbale walls can be erected in a dry environment. It also allows the builder to make changes to the position of walls and windows. Vos often uses the frases ‘ keep it simple’ and ‘use your common sense’. I heard a lot of comments that this technique is pretty straight forward. You can really see it all coming together very logically.
After the lunch break on the balcony of Kamp C we started with the active part. We erected a strawbale wall in a few hours time. The bales were cut, put in place, spiked with willow branches and then fixed with wooden beams. Afterwards the bales were shaven and then plastered. That was the really fun part.
Tired and dirty we went home, amased at how easy it all is. We know for sure now, we want a strawbale home!
