Tire foundation. Covering holes in the top row of tires

I'm building a straw bale house with tire foundation on a slope and realized i need to elevate the foundation with one more row of tires (to make space for more floor insulation. I want 45 cm of foam glass gravel).
But how do i cover the openings in the top row of tires to pack them?
See the video
https://youtube.com/shorts/RGhmdy0Jg4w?si=KMC8U6iwoMGykBAF


Didn't find the tire foundations category, so figured out Earthsip is the most relevant category for my question

So, on the inside of the house there will be packed foam glass gravel layer under the opening.
What about the outside? Packed earth? Packed gravel?

If making a permanent cap over top tire, I can help.  But as for the rest of your project
I won't weigh in.   Many here will assist I think.
Top tire with no gravel or earth inside? Use hardware cloth, you decide which type, then attach to tire. I used small screws into the sidewall. Then coat the hardware cloth circle....or oval or square....with earth, add a second coat with 3 part sand,  0.2 wood ash , 1 part Portland, wet it and  mix.  Strong as an ox.  
My 2 grains of sand.  

On the outside below the new layer of tires I would pack gravel to maximize drainage and not hold moisture near the wall. What do you plan to pack inside the new layer of tires? Foam glass for insulation?

If you don't cut the sidewall off the bottom of the tires, you would have less open space to worry about.

It looks like you stacked the previous layers one on top of the other, not staggered like brickwork (hard to be sure from the tight focus of the video). Do you think this is a good structural idea, and if so, can you do the same with the top layer?

Glenn Herbert wrote:On the outside below the new layer of tires I would pack gravel to maximize drainage and not hold moisture near the wall. What do you plan to pack inside the new layer of tires? Foam glass for insulation?

If you don't cut the sidewall off the bottom of the tires, you would have less open space to worry about.

It looks like you stacked the previous layers one on top of the other, not staggered like brickwork (hard to be sure from the tight focus of the video). Do you think this is a good structural idea, and if so, can you do the same with the top layer?

I don't cut the tires.
I'm going to pack regular fine gravel in the new upper course of tires, just like in the bottom tires. Foam glass is for under the floor only.

Yes, in some places closer to the south side, there's already 2 tires directly on top of each other (not staggered) because of the slope. I think that's ok structurally since:
- the new course will be staggered (i have no choice because can't find tires with diameters matching the tires already in place);
- from the inside, all the height of the tires will be filled with foam glass gravel, so basically the upper edge of the tires is the floor level;
- from the outside, I'm thinking on filling the hight of all but the top course of tires with regular gravel or dirt.

But wondering if dirt/gravel will be able to carry the load of the top layer of tires (and, hence, the house). I believe that's called 'backfilling'? And how to combine it with the French drain, if the soil/gravel is compacted to carry the load.

Have watched and read everything i could in the internet about Earthsip walls and couldn't find the answer.

Rico Loma wrote:If making a permanent cap over top tire, I can help.  But as for the rest of your project
I won't weigh in.   Many here will assist I think.
Top tire with no gravel or earth inside? Use hardware cloth, you decide which type, then attach to tire. I used small screws into the sidewall. Then coat the hardware cloth circle....or oval or square....with earth, add a second coat with 3 part sand,  0.2 wood ash , 1 part Portland, wet it and  mix.  Strong as an ox.  
My 2 grains of sand.  

Thanks for your reply.
I didn't fully understand though. So i cover the opening at the bottom of an empty tire with hardware cloth and secure it in place? Then put dirt inside, and then concrete with wood ash?

As you mention french drain, I would not backfill outside with any dirt, just gravel to drain freely. I would dig the bottom of the exterior drain a bit below the tire base, so no water will want to migrate in under the floor.

I should demure to your choice of how to use the method.  In my experience,  this method was used to
A.  Cover a tire full of earth with a permanent cap and
B.   Cover an empty tire not in use for a foundation