Can You Use Hay In Cob Building?

On the other hand, hay has lower tensile strength and will quickly decompose. Hay has seeds in it and is still living, whereas straw is just the left over chaff and has no food value to it. As they say, “hay is for horses.” Don’t use it for cob!

How much straw do you need for cob?

There is no exact amount of straw to use, but about 15-20% usually works well. Keep repeating the process until all of the straw is thoroughly distributed and mixed into the cob.

How do you make a cob out of straw?

A good ratio of straw to clay and aggregate is one five-gallon bucket of straw compressed, to five buckets of dry ingredients. Keep repeating this process until the straw is used up, constantly turning and stomping, until all the straw is thoroughly mixed in and is the same color as the cob.

What kind of clay do you use for cob?

A: Almost any sort of clay can be used for making cob. Non-expansive clays are best, including those generally sold as “fire clay” and “mortar clay.” Lincoln clays are ideal – very sticky but not highly expansive.

How strong is cob?

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.

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.

Can you use grass in cob?

Grass hay types should perform very well in cob walls. I do not have any longterm data, but I have used grass hay in some of my projects (ag builings) with no immediate issues.

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.

What is the lifespan of a cob?

Gypsy Vanner (also called the Gypsy Horse, Irish Cob, or Traditional Gypsy Cob): 25-30+ years. Hackney: 25-30 years.

What type of soil is best for cob?

clay
A good cob building soil has approximately 15-25% clay content and less than 30% silt. There are many kinds of suitable soil types: clay, sandy clay, sandy clay loam, clay loam, and loam.

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 are the disadvantages of cob houses?

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.

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.

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.

Can you nail into cob walls?

You can also screw wooden hangers to the wall (for coats etc.) as long as they won’t have too much weight on them. For heavier objects like overhead cabinets and so on the best approach is to implant a wooden “deadman” into the cob that you can then screw or nail onto it. Any cob manual should explain how to do that.

What is the best foundation for a cob house?

Concrete has been used for thousands of years by builders for good reasons. It is a great material for foundations. It’s monolithic, very strong, widely available, it uses 99% natural ingredients, and it can be poured into almost any shape that you want. Concrete is a great choice for footers and stem walls!

Can you use pine needles in cob?

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.

Does cob absorb water?

Corncob is an enviro-friendly and biodegradable product that can be used to absorb a variety of fluids, including water, oil, grease, sludge, and coolant, making it ideal for routine shop spills or large industrial absorbency needs such as oil fracking.

What age are cobs fully grown?

By around 12 months old, the horse will have reached roughly 90 percent of their height. After this rapid growth period, the growth rate slows down substantially, typically taking another 4 to 6 years for them to finally reach their maximum height and weight.

Can cobs jump high?

Cobs are renowned for their versatility. Commonly assumed to be sedate and sensible, a fit cob can equally be forward going, fast, fiery and fun. They will take most disciplines in their stride and are often capable jumpers.