Are Adobe And Cob The Same?

The most basic difference is that adobe is formed into rectangular bricks which are dried in the sun before being used, while cob is built wet. Cob therefore lends itself to organic shapes: curved walls, arches and vaults.

What is the difference between cob and rammed earth?

The layers can be rammed continually until the wall is complete, with no need to wait for each layer to dry out. The walls are then allowed to dry naturally once the frame is removed. Rammed earth is stronger than cob, but more expensive because of the shuttering required. For more, see Rammed earth.

What does cob consist of?

Cob, cobb or clom (in Wales) is a natural building material made from subsoil, water, fibrous organic material (typically straw), and sometimes lime. The contents of subsoil naturally vary, and if it does not contain the right mixture it can be modified with sand or clay.

What is the mix 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.

What is an adobe wall?

Adobe walls are normally built on a solid, waterproof foundation of stone or concrete; otherwise the capillary action of groundwater may cause the lower courses to disintegrate. The bricks are laid in a mortar of the same material, then finished with a coat of adobe or with lime or cement plaster.

Is adobe the same as rammed earth?

Rammed earth walls that are placed with forms are similar to the construction using adobe bricks; however, the concept is totally different. Rammed earth walls, in comparison to adobe bricks, are built in more damp, humid climates where building adobe bricks are practically impossible.

How long do cob walls last?

How long does cob last? The oldest cob house currently standing is 10,00 years old. If this doesn’t speak to how strong and durable cob houses are, then nothing will. Cob houses are built to stand forever as long as their roofs are maintained, and they are properly looked after.

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.

Is cob load bearing?

Cob is easy to learn and inexpensive to build. It dries to a hardness similar to lean concrete and is used like adobe to create self supporting, load bearing walls. Cob has been used for centuries throughout Western Europe, even in rainy and windy climates, as far north as the latitude of Alaska.

Can you use beach sand for cob?

Rounded sand that is sometimes found on beach shores is not appropriate for cob because the particles don’t bond together with any strength.

Can you add cement to cob?

Cement mortar mixerswill mix cob if you can handle the fumes and noise. As with manual mixing, the clayey soil and sand is mixed first, then the straw added. The cob has to be mixed wetter than with other types of mixing to allow the cement mixer to turn without too much stress.

Can you use a cement mixer for cob?

A concrete mixer will only tumble the materials round and round. This works for mixing very wet material such as concrete and some earthen plasters. A concrete mixer will not mix cob.

How long do adobe houses last?

Miller projects that the adobe homes built today can survive for as long as 800 years provided foundations and roofs are properly maintained, far outlasting wood-frame buildings.

What is a house made of adobe called?

What they did have was dirt, rock, and straw and, with these materials, they made their adobe houses in communities called pueblos. Adobe is mud and straw mixed together and dried to make a strong brick-like material.

Are houses still made out of adobe?

Adobe is one of the oldest building materials in the world. Though it has ancient roots, it continues to be used across the globe today. Some people still make adobe bricks and construct their homes using traditional methods.

Is it cheaper to build with adobe?

Adobe construction is also quite cheap because it only requires a modest amount of labor to construct, and the labor involved in building an adobe home from smaller bricks is not excessively demanding.

Is adobe as strong as stone?

So it seems the adobe and stone buildings have the same defense against most creatures and some weapons, but the adobe items have less health than stone and therefore can’t take as much damage.

Can adobe houses get wet?

Because fire isn’t used to cure them, adobe bricks aren’t hard. In fact, they shrink and swell with the weather. Here’s where things get problematic: An extremely wet climate prone to flooding might turn the bricks back into mud. Not only that, frequent freezing and thawing can make the bricks crumble.

What are the disadvantages of a cob house?

Disadvantages:

• Labour intensive.
• Relatively slow to build.
• Obtaining a mortgage from lending institutions is difficult.
• Cob walls cannot be laid in wet or freezing weather.
• Insects, notably termites and small rodents can burrow into the walls and weaken them.

Do cob houses get moldy?

There are no mold issues with it at all. So essentially, as long as the cob gets a chance to air out and dry out there’s no real chance for that mold to grow on it.