From this point in it is very important to have fire extinguishers onsite, (if there isn’t one in place already). Whilst straw when compressed or covered with lime/clay gives a very good fire protection (2hr+), lose straw is just tinder! Therefore lose straw should be swept up regularly. Lose straw is also very slippery, and you can lose tools in it, so a regular sweeping is most important.
Before we can do anything with the bales we first need to ‘dress’ them. We do this because bales aren’t actually 100% rectangular, they tend to bulge a bit at the ends. So by ‘dressing’ what we really mean is flattening off the ends of the bales. So when in course we can have a flat end against a flat end. Therefore improving our air tightness, and insulation values.
The way to ‘dress’ a bale goes something like this; Stand bale up on its end, move the excess straw under the string from the bulge to the low point (this is normally a bulge in the middle, to the edge), this is generally best done by hand. Once you have done this for both strings and both sides pull out any excess straw from any remaining high points, but not so much that the strings become lose! A little check at this point is the strings should now look flat against the bale. Now flip your bale on its other end and look how it is standing, if its leaning forward / backward or side to side, its not flat and will need further dressing…. Repeat this process until its flat & then repeat for the other end. Now you should have one dressed bale. Please note that dressing the bales reduces the length by circa 30mm, so make sure this is taken into account for your measurements etc.
The first bales go in quite easily onto the base plate ladder, held into position with the wooden stubs. When laying the bales, make sure you start in the corners, so they are nice and tight in the corner. Using your boards as a guide. With a hand either side of the bale (one on the outside of what will be the house, one on the inside) check the bale is sitting centrally on the base plate. Once you happy with the position move on to the next bale. This process reminds me of playing with Lego as a kid. I'm probably still a big kid TBH....
When putting the next bale in try to get it snug up against the first bale. This will mean better insulation / air tightness values, and save on the stuffing that comes about later. This is very important, SNUG NOT TIGHT! If it’s tight, it may cause the whole wall to snake, and takes a hell of a lot longer to sort out, than if you did it properly in the first place! Don’t be tempted to cram bales in where they’re tight. The only reward for being a strong macho person in straw bales is the fact you get to practice correcting your mistakes!
Pictures from earlier straw works course, it seems I got so excited with the walls going up I forgot to take many photos!
At the corners of the building, it’s important to tie are bales together to give them added strength. First tie the string to the inside bale, then loop under and over the first string, then loop under and over the second string and tie up. Remember snug not tight!
This is my crude plan showing the tying of corners.
Stuff vertically in between bales where the strings meet, as there is normally a slight gap here. There shouldn’t be gaps anywhere else, as the bales have been dressed! Remember snug not tight, or the whole wall may begin to snake! There is no need to stuff horizontally as this will compress. If there is any horizontal stuffing, the compression could become uneven!
Depending on the machine used, most bales have a cut and folded side. The cut side is better for plaster adhesion, so this is the side we have on the outside for the first course. As it could be a potential weak spot for plaster. But we need to alternate the cut and folded side per course, as the folded side compresses more. So if we did it all cut side out our walls would bow!