Can You Make Cob With Pine Needles?

Cob is a type of earth building technique that uses a mixture of earth and a fibrous organic material (typically straw, but in this case pine needles) that adds tensile strength.

What is the mixture for cob?

Cob is a mixture of clay, sand, straw, and water. Clay is the binder; sand gives the mixture strength; straw provides tensile strength (think “rebar”); and water helps activate the clay to hold the mixture together while building.

How do you make cob material?

Cob is a mixture of approximately 1 part clay, 4 parts sand, and 1 part straw. You can buy bagged clay in powdered form (go to Laguna Clay for local distributors) and masonry sand from your local supply store.

How do you make a good cob?

Mixing Cob: Step By Step
Pour off the water from 3 buckets of clay, and dump the clay into the sand pile. Remove your shoes, and get stompin’. Every minute or so, use the edge of the tarp to pull and roll the material to more quickly incorporate the sand and clay. Add water if necessary.

How thick should cob walls be?

How thick should cob walls be? The thinner that cob walls are the less load bearing capacity and thermal mass that they will have. I recommend the width of cob walls be between 18 to 24 inches as a standard. This gives plenty of load bearing capacity for a one story building and plenty of thermal mass.

Is cob as strong as concrete?

Cob has unique properties which make it as strong and more durable than concrete (see ‘How is Cob so strong’) the oldest Cob building is over 10,000 years old. Cob is resistant to fire, termites and mould.

What kind of sand do you use for cob?

Concrete sand is a great choice for cob. It is rough and holds a variety of particle sizes even including some small pebbles. Using this sand will help prevent serious cracking. Masonry sand is a finer version of concrete sand and is usually a bit too finely sifted for large cob constructions.

How long does it take for cob to dry?

It can take months to years for your cob to dry out fully. The bulk of the moisture will dry out in the first year, but it will not fully cure for 1-2 years beyond that. Once you’ve built your cob house and added your roof, allow it to breathe for several months before moving in.

Can you make cob with hay?

Hay has seeds in it and is still living whereas straw is just the left over chaff and has no food value to it. Hay is prone to sprouting and could make your cob walls look like a giant chia pet! It is also prone to rotting. As they say, hay is for horses.

What keeps cob from washing away?

Why doesn’t it wash away in the rain? Cob is very resistant to weathering. Because of its porous nature, it withstands long periods of rain without weakening. However, too much exposure is best avoided by the “boots and cap” strategy: wide roof eaves to protect the walls and an impervious foundation.

What is the difference between a cob and a gypsy cob?

It was often referred to simply as a “Cob”, although the term cob defines a short-legged, stout type of horse rather than a breed. Other names are used worldwide for the breed, such as Gypsy Cob, Gypsy Vanner and Tinker Cob, alluding to its association with the travelling community.

What makes a good show cob?

“Regardless of which section they are being shown in, a cob should be a thick set animal with good limbs,” says judge Jack Cochrane. “They should have short cannon bones and good feet. They should also have a decent depth of girth with a good strong back and hind quarters.

Do cobs need rugs?

Many horses, especially breeds such as the native pony and cob types, can adapt well to winter weather and easily cope without a rug when they have adequate forage and access to shelter.

Can you put nails in cob walls?

Nails must be hammered in to the sides to hold it in the wall. You are going to have to keep checking they are level as you build up, as the cob is likely to push them around a bit. The horizontal bar inside the wall also adds strength and stops the deadman falling out.

Do you need permission to build a cob house?

As with all builds, it is necessary to get planning permission and satisfy Building Regulations. While this may be complicated there is no reason why you should fall short of meeting the Building Regulations, but obtaining planning permission will depend on the outlook of your local planning office.

Are cob houses cold?

Even with insulation in the floor, roof, and foundation, heating a cob house is a constant battle against cold outdoor temperatures. The mass is totally exposed to ambient cold air temperatures more than it is exposed to warm indoor air.

How long will a cob house last?

If you have doubts about the durability of a cob house, then it’s worth mentioning that the oldest cob house still stands after 10,000 years of exposure to the elements. Also, making one for yourself and your family isn’t rocket science as it is very easy to build with the basic knowledge of construction.

Is a cob house fireproof?

Cob is also highly fire resistant—it was used for centuries to build ovens and kilns—and earthquake-safe when built to the methods outlined in the new IRC appendix. And, says Nilsson, cob buildings are non-toxic and environmentally friendly, often using clay-soil from the site.

Does cob insulate well?

Put bluntly, cob is a pathetic insulator. This goes for any earthen building material. But what earthen materials lack in insulation properties they make up for with thermal retention. Cob is also a very poor conductor of heat and has very low thermal conductivity.

What makes a good gypsy cob?

The breed standard states that a traditional gypsy cob “should be a strong, sturdy and powerful cob coupled with an abundance of luxuriant flowing mane, forelock, tail, and leg hair which is known as feather. They should always have plenty of heart room, and a deep girth to match.

What is the oldest cob house?

The oldest known cob structure is over 10,000 years old. It is still standing but is likely to have endured because it has been looked after by generations of people.