Well it’s been an extraordinary month on the Sherborne build. You may remember we are building a straw bale roundhouse. It’s being built with community involvement and will become a community building. Going from so much planning and preparation into actually being on site has been very exciting indeed. Here is an update on the first weeks of the build.
We started off earlier in July by setting up the site. First of all the fencing was delivered and set up so we could keep the site secure.
From the middle of the month, Tom – my nephew – arrived as the first official addition to the Huff and Puff Construction employee list. We marked up the site and began to remove turf from the build area.
There is a lot to set up on a construction site. On this site we are using the Youth Centre’s facilities for the welfare of those on site. We have designated fire and first aid points and a double gazebo – kindly loaned by Sherborne ArtsLink – to give us protection from the elements.
Having sampled the soil on site I knew we had about 30cm of a clayey topsoil, with solid clay below. We dug the hole for the first pier – I say we, but Tom did most of the digging – and it took about a day. This was chiefly because the ground has dried out so much and it’s really hard going. We have 11 piers in total, so a rethink was required (one which you’ll see later, in the form of a hired breaker).
We moved on to cutting the timber for the ring beams. The building will have two timber structural ring/box beams. One beneath the straw bale walls and one above. These fix the bale walls in position and tie the whole structure together. Whilst straw bales are really easy to put a curve in, timber is not. With a circular building the ring beams call for a lot of curved sections to be cut. I’ll go into the technical details of this more in later posts. For the top and bottom of the ring beams we are using SmartPly OSB3, 18mm thick. SmartPly is the current green building OSB of choice because it is manufactured without any added formaldehyde. Building suppliers can probably source it for you even if they normally have a different brand.
In order to get the template cut to the right size, we laid out a section of board on the marked up site. For all the complexities circles bring, it is great to be able to put a stake in the middle of the site and work out sizes just by running out a piece of string, rather than having to make complicated calculations. A section was marked up on the OSB board (a 2440mm x 1220mm sheet) and cut out to be used as a template for all the other sections. By working out the exact internal and external circumference for the OSB element we were able to work out how many section we needed – 8.8 in our case – and so another template was made up for the final, ninth section, to complete the circle. It took probably two or three days to get these sections cut.
Our first volunteer arrived this week in the form of Robert. Tom cut up noggins that will rung from the inside to the outside of the OSB sections and Robert glued and screwed them up into pieces two high, to give us the 240mm internal height we need in the ring beam. Although it was extra work to do this, the full size we wanted wasn’t readily available – and it is normally cheaper (and stronger) to fix two pieces of wood together rather than to use one solid piece. The glued up pieces were set aside to dry.
That brings us up to Friday of this week. After weeks of sunshine we actually saw a bit of rain. I took cover in the gazebo to make up a jig so we could assemble the curved ring beam sections and noggins reliably. We have 36 sections to do in total, so although this took a while, it should be time well spent – plus we can use it future too. Offcuts of OSB were used to create sections for the noggins to slot into, so the tops can be glued, then a curved section fitted on top and nailed and screwed into place. Then the complete section can be removed and the next one made up.
I hope you are enjoying reading about the build. Please do leave comments via the comments section below, or use our contact form, or Facebook if you’d like to get in touch or get involved in the build.
There is a bigger gallery of photos here (and a frequently updated album of all the project photos on Facebook here -):