Cob Garage

Hi there,

Has anyone built a cob garage? If so, will you be willing to share some pictures?

Is it a bad idea?

I need to replace my dilapidated garage, and cannot afford to pay for even 1/10 of the money that contractors are asking for. Cob seems like something that I, as an office worker, can learn to do. I'd also like to add a small workshop with a small fireplace, and a storage area for garden tools, and integrated exterior alcoves for rain barrels and bird feeders.

As this is not a house, but an outbuilding, I imagine the building code obstacle course will be less onerous.

Thanks for your time. Evan (Michigan)

It's not a bad idea, however you still would need some cash for the slab, stem wall, doors, etc. if nothing else.

One idea would be to see about having a pole building put up. Then put in the slab floor. Next, in fill the walls
placing windows/doors as you could afford to. Kind of a build as you go project. All of this would have the
protection of the roof, which would make it that much easier as a one person build. Once the floor was in you
could start using it as a carport until you finished it.

Just some thoughts

Evan James : As you say that you have a dilapidated garage, i amy thinking about the possibility of the condition of an already existing slab of concrete, there is a general
rule in building about sturdy galoshes and a good hat that is even more important for a Cob structure. a good foundation preserves the roof, a good roof with eves with
generous over hangs protect the foundation !

What shape is the existing foundation in ! If it is good and money is tight then build an open side pole barn structure over the top, plan your build to include wide over hangs
to move your buildings drip lines out away from where they can damage your Cob side walls, and plan on drainage improvements .

If the cement slab is all broken up think about saving the chunks of concrete as infill.

Now you have time to speculate on where might be a better place for your garage than its present location, you could have a pole barn up and park your car under it now,
and then in the spring do the cement work. in any case you will have to see if you can use parts of the existing footers that for your location in Michigan.Your footers must go
below the frostline or depth of frost ! a french drain will save your foundations much of the usual frost problems but I would not try to get by the Code enforcement officer
with just a concrete slab, any more than my code enforcement officer in New York !

So You have a slab with good footers and a french drain to carry water away, and a pole barn with wide eaves over head at that point it will be simple to follow Jamie McBrides
suggestion and infill with a couple of feet of stem wall to protect the cob and then just infill with cob, building on the windward side first seems most reasonable, you will have
time this winter to observe your prevailing winds and snow load ! Good Luck,BIG AL !

I see the original poster did not reply. However I am dragging this thread back to life.

I have a 40' x 60' brand spankin' new pole barn. I am considering doing cob on the interior walls, and possible cob flooring.

Any cob experts want to give me advice?

1.) Can I park a 4000lb car or truck on a earthen/cob floor? Should I add a little concrete to the mix?
2,) If I use cob on the interior walls, how might that effect the moisture buildup between the cob and exterior metal panels? Is this a bad idea?
3.) Would a "wattle and daub" layer on the interior walls with an air gap between the metal panel and wattle/daub interior wall breath better? Maybe stuff some straw in between for insulation?

Hi Ray, sorry this slipped by without any sort of reply.

The earthen floor will not be able to handle a heavy vehicle. I'm not sure about doing it as soil cement, it would probably give it some better compression strength, but I've never done this and do not know for sure.

I'm a bit confused about the exterior wall questions, would these earthen walls be "exterior walls" with metal cladding on them? or would they be true interior walls making room divisions within the building? I wouldn't do metal against  cob as you may get condensation build up that could weaken the cob. Wattle/Daub probably wouldn't be much better up against a metal surface. Straw wouldn't do much unless it was a thick layer to prevent heat escape from the sides of the building which would cause the condensation, it would probably end up molding. Best bet for thickening those walls would be to attach some poly iso sheets or blueboard so that the temp isn't different between the outside surface and inside surfaces of the metal.

The question would be why you want the cob or wattle on the inside? just aesthetics or are you looking for mass? Neither will given insulation.

Concrete is the best surface for parking and working on vehicles. Earth will crack, dust up etc.

I too am confused by your discussion about the walls.

Lets start by asking what do you hope to use on the exterior walls?
Interior walls made of cob will be hard yakka [work] and if you want separate areas in the shed, stud walls may be quicker, easier and better value that cob in the long run.

For an existing structure that will be covered in Cob do the walls and roof need to be weatherproofed and reinforced?

Heath, here are a couple of threads that might offer some suggestions:

https://permies.com/t/161254/Cob-walls-existing-shed-frame

https://permies.com/t/61082/Brainstorming-conversion-attached-barn-cob

Maybe one of our members can answer your question.