They don't call slip straw "light straw clay" for nothing. The mixture is pretty lightweight which is why we are capping all the walls with what is referred to, not so elegantly, as heavy straw clay. This mixture tops the slip straw walls to better keep the wall secure and in place.
The mixture is made much the same as slip straw. It starts with mixing up heavy clay slip.
The heavy slip is added to fluffed up straw...
... and the mixture is needed together to form a heavy straw clay loaf with the slip well incorporated in the straw.
We add more slip into the mix and keep kneading, ...
... and making sure there are no clay lumps and that the mixture is thick and sticky.
The loaves are then used to top off the slip straw walls. Here Flora hands them up to someone stuffing above.
Below you can see the heavy straw clay on top of a finished slip straw wall section. Now the wall will dry strong and the heavy straw clay will help things stay in place.