HAS Straw Bale Qualification
As part of our Growing Up Green Project, this week, Hill Holt Wood hosted students from the Humanitarian Architecture Society of the University of Sheffield. The group had visited previously last June to assist with the hempcrete casting in the Bunkhouse porch. The three-day workshop required the students to brave camping in less-than-ideal weather conditions in the Roman Villa opening.
WEDNESDAY 4TH APRIL 2018
The workshop began with a quick introduction to the course and the fundamentals of building with straw bales. Laced with anecdotes, fun facts and brainstorming activities, the team tried to keep the theory side of things fresh and exciting. To reward the visitors for sticking out the theory-based day, a rainy practical session was held in the birch area to prepare the foundations ready for the following day’s build.
The group were split in two, with one group joining Aaron to learn about Rammed Tyre Foundations, whilst the other group joined Ben in assembling the Base and Top Plates. Despite the rainy conditions, spirits remained high and questioned remained observant and sharp.
Alas, as things go, although our rainwater harvesting system was filling up rapidly, a faulty UV filter meant that our muddy participants were left shower-less following a hard day of grafting. A complementary supply of firewood was offered as an alternative, which made the cold and wet weather slightly more manageable.
THURSDAY 5TH APRIL 2018
As the longest of the three days, Thursday was action-packed and productive. The timetable allowed for the majority of the paperwork to be completed in the morning session, leaving the entire afternoon to get started on the wall construction.
Following a few recaps, brainstorming activities, and a thrilling analysis of Risk Assessments, the group were divided in two to construct a 1:10 model of the proposed straw bale development. This allowed participants to visualise each stage of the construction process and how quickly the building can come together. The morning session was concluded with an in-depth comparison of straw bale construction and convention brick and block construction.
As the group were so efficient in the morning session, they were able to get up to the Birch Area before lunch to get started on the final prep work for the build. Each bale was taken from storage and participants took part in splitting bales into half bales (which would be necessary in the walls) and dressing the full bales ready for construction. The students also took part in cutting and sharpening hazel stakes to drive into each course of the wall.
Following lunch, the construction of the walls was ready to begin. Courses were built up using a combination of full-bales and half-bales, ensuring to include the structural door and window boxes where appropriate. Hazel stakes were driven in at each course to bond the bales together – the activity that most architecture students excel at, unleashing their built up fury on hammering in the stakes.
Following a long day of construction, with a functioning UV filter back in place, participants were treated to cold showers for their efforts. Following dinner, the participants headed back down to the Roman Villa area, where a camp fire was started again, and conversation ranged from feedback on the course, to which member of the group would be eaten first if “things were to turn”.
FRIDAY 6TH APRIL 2018
After a quick briefing, including a reciprocal roof presentation and modelling activity, the group threw on their PPE and headed up to the Birch Area once again.
The team made light work of finishing off the walls and tidying up any imperfections. An additional scaffolding tower was constructed for the assembly of the top plates. However, due to an oversight on the first day, one section of the top plate needed re-assembly in order to fit together.
Once the top plates were in place, the walls needed to be compressed. Participants were walked through the process of assembling a ratchet strap on each wall. The group then levelled the top plate, compressing each side in accordance to the wall level. Once the levels were suitable, the final dressing and persuading of the bales took place to ensure there was a flat and level surface to apply the wall finish to, whilst also improving structural stability.
As a follow up to the reciprocal roof presentation earlier that morning, Aidan, acting as the Charlie stick, walked the group through assembling a four-pole reciprocal roof on top of the structure. Whilst the group waited for the lime putty to be prepped, they were also shown how these principles could be adapted to assemble a roof of six poles and beyond.
Ben concluded the practical session with a demonstration of rendering using a lime putty and sand mix. Unfortunately, due to limited resources, only a handful of the participants were able to have a go applying the lime.
The day was concluded after lunch with final touches added to the workbook to ensure all participants would pass the course. Both Hollie and Aidan demonstrated a double reciprocal roof in model form, with both examples being lost to clumsiness before photographic evidence could be taken.
We received positive feedback from the students before they boarded their coach to take them back to Sheffield to deal with the stressful reality of looming deadlines. Overall, it was a successful workshop that will hopefully inspire architectural projects in the future, and will help kickstart a more regular programme of workshops at Hill Holt Wood.
A massive thank you to Our Bright Future for funding Growing Up Green and allowing us to teach such valuable skills to young people. We are currently looking to roll out a series of workshops with our funding, to get young people aged between 11-24 involved in natural building.
If you have a group that are interested in getting involved, please Get in Touch!