Tuesday 3 June 2014

Wall Raising Week 2

Day 1: Monday 2nd June.

POOSHers = 2, Friends = 1. Weather: dry and sunny, rain forecast later (which did not materialise)



And we start week 2 where I left off on Friday - putting hazel stubbies into the base plate and fitting the first course of bales as carefully and as straight as we can. New POOSHers Laura and Jam are here for two weeks, and there are likely to be quite a lot of photos of them.



After completing the first course, the second course is relatively straight-forward bale laying. If I had known my average bale length at the design stage, I would be forging ahead with just the occasional half-bale to make. However, with the slightly shorter-than-expected bales I have bought, a bale needs to be shortened for each of the wall segments, which is five per course (because of the door opening); six on course two (window opening) and seven on courses three and four (two window openings). So most of the day is spent adjusting bale lengths.


Large window box in position sitting on the first course of bales. The box is pinned through the bottom into the bales it is resting on.


Second course nearing completion. We have moved some more bales down from the shelter for tomorrow.

Day 2: Tuesday. Two POOSHers. Weather: warm, cloudy, occasional drizzle

Another day, another course of bales. This is quite a relaxed pace of work for three people. There are bales to dress, careful positioning, bale length adjustments, positioning and pinning of the second window.



We had a "make your own persuader" session first thing, to get ready for bale staking when we reach the fourth course. Logs from the wood store, hazel from the leftover hazel pile.


Small window box, inverted, with its bottom stakes showing. The box is stuffed with sheep fleece insulation.


And this is the end of the day, with the third course completed. Stack of bales in the centre ready for tomorrow, some split bales in the the window box. The wall is getting higher to work on now. We have the scaffold outside, but may not be able to work from it tomorrow because there is rain forecast.

Bale customising with ratchet straps:




I have been experimenting with using a ratchet strap to help compress bales when splitting them. We are putting new bale twine around the bale sections in the conventional manner with a bale needle, but before we tie the strings with a pulley system of hitches, we are using the ratchet strap to compress the bale between two boards.


The string I am holding above is the original bale string which was extremely tight and now has quite a lot of slack in it. Next, you tie up the four new strings (without having to strain to make them as tight as possible), cut the original strings and release the ratchet strap. The straw expands to make a couple of tight bale sections.


We found it was best to have the ratchet on the end of the bale where a board is. If you have it along one side, you get higher tension there than on the other side, and your bale goes all trapezoid. 

Day 3 Wednesday. POOSHers = 2, from other networks = 1. Weather: Rain

Rain on and off all day, so inside work under the covers. We have completed the fourth course, "persuaded"  the long back wall into the straightest shape we can manage, and staked the first four courses of the back wall will hazel.

We have also stacked sufficient bales to finish the fifth course ready under the building covers. This is a relief, as I had some water leak into the top of my bale stack, and i suspected that it might have penetrated down to the bottom of the stack, but haven't been able to assess the loss until now. I bought around 18 bales more than I needed for contingencies and because of the pack size, and I have water damage to around 14 of them.


Straightened out with a little persuasion

Laura - Straw-lover
So: just looking at the window in the background of this picture: I think I got the height of the window about right. The straw is about 40 or 50 mm above the top of the window box, but after pre-compressing the straw, the box top should be level with the top of course four. The other window doesn't look as well-judged at present.


First stake

High stakes



More stakes

Day 4 Friday. POOSHers = 2, Weather warm, dry and sunny.

Thursday was a rest day, so Friday is the fourth and final day of week 2. And it is also the first dry day of the week, so a good opportunity to do some outdoor work. We are going to start making the wall plate, which will sit on top of the final course of bales.

First job: measure the base plate under the bales (again!). The wall plate should be the same size. Then we laid out a rectangle of this size on the grass with fencing pins and bale twine and measured the diagonals to make sure it was a perfect rectangle.


If you read this blog in March, you might have seen that I cut all the OSB for the wall plate in advance. Laid out on the grass today, it was a pretty good fit - it just needed a few millimetres taken of here and there. We laid out, measured and cut 4 x 2 timber on the the OSB for the outer beam.


Cutting noggins with a chop saw. The saw is fixed to the bench, and I have made an end-stop for the timber so we could cut off 350mm lengths without measuring each one


                            


Inner beams cut to length. It is not essential to do overlapping joints, but it's cosmetically very pleasing.


This took the whole day. We'll start next week gluing and screwing the beams to the OSB in six sections, ready for final assembly on top of the straw.

Tuesday 27 May 2014

Wall Raising: Week 1

I set the date for the start of wall-raising a long time ago: May 26th, Bank Holiday Monday. Half-term week.  Lots of students just finished their exams. I thought this would be a good time for volunteers to come for a week.

Day 1: I have two resident volunteers and five who have come for the day. Three of the seven are long-standing friends; two I have met through the POOSH network, and two I have met through other networks.

It's warm and sunny. Perfect weather for straw bale work. And the jobs lined up are: finish filling the wall cavity with RFG gravel; start making the base plate; make some hazel stubbies and finish putting up the tarps as curtains around the building.

But: there is a design issue to sort out first: how long are my bales? I have designed the entire building with the assumption that the bales I use will have an average length of 1050mm. The very first job of the day, before we start making the base plate, is to dress a few bales, lay them along the stem wall and measure them.




This didn't take too long with eight people. Also, the bales have very square ends already. I think it must be to do with the mechanical strapping, handling and storage of the bales, but they needed much less dressing than bales I have handled before


We laid eight bales along the stem wall and measured them: 7980mm, an average length of just under a metre. This meant that my longest wall of 8.4 metres was going to be closer to 8.5 bales than the original 8 bales I had planned. Time to get out the revised bale plan and elevation, now 5 x 8.5 bales rather than the original 4.5 x 8. It's a bit of a problem: all my openings are multiples of 1050mm, so I can foresee quite a lot of bale splitting coming up. I will also need around 10 more bales than originally planned.

Luckily, I bought some extra bales. Unluckily, or carelessly, I have already got some of them wet. It turns out that the green tarp on the dome is only waterproof for a few weeks, then it start letting water in. I have eight bales already with damp patches.

Lunch outside. Hats & suncream needed.

Then it was on with the base plate:


Making stubbies in Bodger's Corner:




Putting the curtain sides of tarp around the building. My tarp supplier had to supply stripy market stall tarp instead of white. Luckily, I chose white with red stripes:

So they are nicely colour-co-ordinated with the old cargo netting that one of my friends has kindly lent me. It looks like I'm opening a circus! As usual, there are no photographs of the afternoon-long struggle to get the tarps up, because I was the one struggling with them.

Tea break in bodger's corner:



Thanks to everyone who contributed to a great first day. We have most of the stubbies, a half-constructed base plate, a few dressed bales and  the south and west sides of the building protected from rain. Unless we had the unlikely combination of heavy rainfall and a north-easterly wind, we should be able to keep the site dry.

Day 2:  We woke on Tuesday to heavy rainfall, blown in on a brisk north-easterly wind. This was probably the wettest day for several years in this area. There were flash floods in many residential streets in Norwich. Water poured in through the exposed eastern side of the shelter whilst I fought with tarpaulin sheets outside. The tarpaulin roof started to dish with pools of water in between the horizontal lathes.  It wasn't like Monday, and there aren't many photos of happy smiling POOSHers.

There were in fact no POOSHers today, but two volunteers from other connections.

                           



Great work from Mary and Katy in terrible conditions. By the end of the day, the sections of the baseplate were complete,



I spent most of the day trying to keep the water out. 

Day 3: POOShers = 2, friends = 1, other connections = 1. Weather: cloudy and damp, rain in the afternoon. 

It was outdoor weather in the morning, and I had two new volunteers, so we spent a little time in bodger's corner sorting and shaping the hazel. In the afternoon, Owen and Oskar assembled the large window box, whilst Paul and I worked on completing the baseplate



              

I believe this is old-school window method for straw bale building, but my straw bale education does not include the post method, and I don't have the tools for making slots for window posts in my bales. It's a bit of a monster: a heavy lift for two people, probably better with four.



Day 4. POOSHers = 1, friends = 1. Weather: light rain, overcast.

I found two buckets in the garden this morning, both with around 3 inches of water in. I'm fairly sure they were both dry buckets on Monday, and that all the water in them has fallen as rain since then. In this area, three inches of rain represents about one tenth of a year's average rainfall, so I think it would be fair to say that I have not been very lucky with the weather in my chosen "Build" week. 

So another indoor day, but not wasted. We have finished preparing the hazel:

Stubbies: (300mm, press fit in a 32mm noggin hole)

                        

Withies: (900mm, overall thickness less than 25mm)


And long stakes:  (1350mm, any diameter)


I may have just made up some of these names. We have made 50 of each.  There may be a few more needed for the window boxes


Paul has been shovelling the RFG into the cavity. I had originally planned to place sheepwool insulation in the baseplate, but I have a surplus of RFG so it seems logical to keep filling the cavity up to the top of the baseplate. 

Here's a photo of rainwater on a tarpaulin. The reason I include it is that this photo is taken inside my dome straw shelter. The rain is seeping through the outer dome cover, and would be soaking my straw if I hadn't put another tarp or two inside. For the record, the dome cover is a Tarpaflex "Super Tarpaflex" mid-grade 140 gsm 8 x 12 metre tarp. Don't waste your money on one of these!


What else? I've made corner guides for all the corners, all beautifully plumb and square, I hope:


And I've had a big tidy up, and made a new tool station that takes up a minimum of space in the tent:


There is no more carpentry to do. Tomorrow, it's straw wall-raising.

Day 5; Sunshine! And no rain. 1 POOSHer.

So: Curtain up! I suppose it would be possible to raise the walls with the side tarps down, but I prefer to have the sides open when I'm building. We have laid some bales along the plinth wall. They are not in their final positions yet, we are just sizing them up.



Straw bales do not come in standard lengths. In fact, there will be some variation in bale lengths from any baling machine. We have discovered that eight bales (and one crossways at the corner) will be a good fit on the long back wall, but that the two short and two part-walls will all most likely require a bale to be resized to fit. Bale resizing takes two people around 15 to 20 minutes per bale, and requires concentration and strong hands, so the poor estimate of actual bale size  is going to cause quite a lot of extra work.


Hazel stubbies fitted to the baseplate. we are going to lower the bales onto the stubbies so that they can't move sideways. There will be 23 bales in the first course, and we've got 46 stubbies ready


and here goes the first bale.



Some of the stubbies are a little loose, and require a few hazel chips to be hammered in to wedge them.




And we got about 2/3rds of the first course of bales in position before Paul had to leave. Two bales were successfully shortened, although not always at the first attempt.

Positioning bales over hazel spikes and forcing them down is not a job to try and do solo, so once Paul left I concentrated on getting the tarp sides back in position, moving more bales down from the store and tidying up. I'll be building again once I have some volunteer help - hopefully on Monday or Tuesday next week