Earth Rammed Tyres as a retaining wall

Earthships: How to Pound a Tire from Earthship Biotecture on Vimeo.

As Spring draws closer, I am nearing the end of my tyre ramming in the back garden. I am just completing two retaining walls and a foundation trench consisting of over 300 tyres. While I’m sure this does not make me an expert on the subject, I feel that building in the area that I am, I have had to cope with challenges that are not normally faced by other blogs on the subject I have read. My construction of the first wall was admittedly amateur in places, and I want to do my bit to ensure that anyone else taking on the task of constructing a retaining tyre wall does not make the same mistakes as me.

When you are looking to build a retaining wall, you need to think about a couple of aspects, which I will address below:

  • Use of the wall
  • How you want the wall to appear afterwards
  • Height of the wall
  • The type of soil you are retaining

Use of the wall – do you want it to be waterproof?
One of the mistakes I may have made with my first tyre wall is not considering this aspect. My tyre wall was just thrown into the ground, not thinking about putting a waterproofing membrane behind it with a drainage trench. Some people raised concerns about the water behind the wall pushing it over, but I found that the water simply seeps through the small gaps between the tyres.

If you want the tyre wall to be waterproof, you should consider a french drain design with a waterproof membrane between the drain and the tyres. This means any excess water will drain down the french drain and out through a pipe you can install in the wall, or wherever you want. By doing this, you ensure that your tyre wall will be waterproof, which is ideal if you are using it for an earthship style building! For information on waterproofing, skip to the end of the post.

How you want the wall to appear afterwards? – Do you want to plaster over it?
If you want to avoid the bare tyre look on your finished wall, you will have to think about plastering it. On an exterior wall, this is going to be difficult using natural materials, but it is not impossible. One thing you have to ensure you do, however, is waterproof the wall, so that there is no water leaking through gaps! This in itself brings its own complications. I’ve tried to outline these at the end, followed by a section on plastering.

Height of the wall – How much are you retaining?
In my building work, I have built a tyre wall six courses high. This stands approximately five feet, or 1.5 metres, maybe a little higher. I don’t think I would be comfortable going much higher than this the way I am building, as my walls are pretty straight, albeit with a slight step back as it goes up. I also have iron rebar through the walls to act as reinforcement. If you are looking at building walls approaching 2 metres (around 7 feet) or higher, then you should definitely consider two things, the length of the wall, and stepping the wall back as you climb. If the wall is longer than, say 5 metres, (about 5.5 yards) then consider either curving the wall or building in a buttress to strengthen it.

Planning, planning and, oh, more planning.

Apologies, it has been a while since I wrote a decent post on here. It seems all I’ve done for about a year has been ramming tyres. Probably because that’s pretty much all I have been doing!

At the last count, I’ve got about 50 tyres to go to finish the final retaining wall and I cannot wait to get them out of my way! I’ts not that I haven’t enjoyed ramming the tyres – far from it, actually, I think ramming tyres is brilliant fun and has got my upper body into a decent shape! It’s more that, after two years of digging trenches and turning a big hill into a terraced garden, I am ready to move on to the next stage.

This next stage is all happening this Easter. It’s exciting and equally terrifying. I ordered the straw last September and had it stored at a friends farm in Brecon. In five weeks, that straw will be making its way down and the walls will be going up, along with the roof of the building.. all of this will take place over one week!

This is the pitfall of building without a timber frame. Since I need the straw to hold the roof in a monolithic structure, the walls need to be built, then the roof placed in top. When you have a material like straw, you need to keep it protected, and for those precious few days when the roof is going up and being covered, you have to pray for good weather and a smooth operation. It’s no wonder a lot of people would go for the timber frame approach!

To ensure that the week goes smoothly, everything, and I do mean everything, has to be planned to the smallest detail. I’ve got a shopping list as long as my arm, consisting of roof timber, lime putty, tarpaulins (essential weather protection kit!) and clay. Delivery times are being considered, as some of the materials will require lugging up to the back of the garden, and to be honest, it can be a very overwhelming operation to plan!

This is where I am at currently. I’ve just put in the order for the timber for the roof plates, and the joists, which I hope to construct before Easter. I’m bidding on a Gripple for compressing the walls on eBay, and emailing lime suppliers about prices and delivery dates. It’s mental, but as Easter draws closer, I can’t wait for it all to arrive and all to fall into place. I won’t be surprised when it’s all over that I get bored and look for my next project, because this stage feels very addictive!