Sept 30th, 2018: Cob House

[Gravdigr]

What keeps stuff (grass, weeds, flowers, marijuana) from growing on it?

Don't bugs of every description lurve dirt?

[Griff]

Cob may be a little different, but I think rammed earth construction usually has a binder mixed in it, a little cement. The soil itself is screened mixed and tamped making it a bad growing medium. I've got a book called Alternative Housebuilding by Mike McClintock on my shelf that gets into the process.

[Carruthers]

Until this thread, I'd never given much thought to the wychert houses in the area around Haddenham to the west of Aylesbury.

Wiki:

Wychert or witchert (with a number of variant spellings existing and meaning "white earth") is a natural blend of white chalk and clay which is mixed with straw to make walls and buildings, usually then thatched or topped with red clay tiles.
This historic method of building construction is localised to Haddenham and the surrounding local area in Buckinghamshire.
One of the largest known wychert structures is Haddenham Methodist Church.

The method of building with wychert is similar to that of a cob building.
To maintain the rigid nature of wychert it must not become too dry for risk of crumbling, nor too wet for risk of turning to a slime.
Keeping wychert well ventilated and not subject to excess condensation is therefore highly recommended.
Any render applied to a wychert wall must therefore be of a breathable material — rendering wychert walls with a lime based render is therefore common practice.

Link

There's a short academic paper (pdf) from the Texas A&M University College of Architecture linked in the above Wiki article via Wayback Machine:

The Witchert Buildings of Buckinghamshire, England:
Learning Sustainable Construction from our Ancestors

Wychert appears to be a nightmare to maintain and I wonder if it is possible to raise a mortgage on such a house.

Restoration work in progress:



M H Restoration

Earth Buildings and Their Repair

[xoxoxoBruce]

Originally Posted by Gravdigr

Don't bugs of every description lurve dirt?

From Carruther's link...

The deterioration that can be seen in figure 3 was caused not by water but by the activities of Masonry Bees who have nested in the walls. Insects and rodents make no distinction between earth in the ground or in walls, and their activities have caused considerable damage to many buildings in the area.