CAT- DAY 4

WATER SUPPLY/SANITATION

On the final day students were introduced to the water supply/sanitation processes

that are adapted by CAT. We were made to understand the sustainable system CAT uses to collect and treat the water supply as well as treating all of the waste products produced at the site in a variety of ways:

• Composite Toilets

• Reed Beds

• Septic Tanks

• Leech Fields

• Water Filters

• Water Conservation

• Rainwater Harvesting

We were shown around the displayed

composite toilets, leech fields and water filters

at CAT, where we observed each system and were made to understand the processes at each stage comprehensively.

An example of this is the domestic organic

waste management and utilisation system;

a compositing system devised to collect all household

waste water from showers, sinks and washing machines.

Through the combined actions of the reedbed substrate,

microbes and the plants themselves, all sewage

and grey water on the site is treated.

Compost toilets collect the waste products which are then treated with sawdust and left to decompose, however systems that are poorly maintained could cause insects, odour and health hazards.

The sustainable water supply/ sanitation systems were visually presented and explained to the students in-depth at each stage of the process, giving us a better and wider understanding on the positive impacts and uses of the functions on the environment & sustainable building designs.

STRAW BALING

For the final practical session the students had to design a section of a straw bale wall on a

timber frame with a suspended ceiling within groups of 2.

We initially started off with a mini practical task where we stacked up the small and large straw bales to create an igloo like shape providing adequate shelter which demonstrated the texture and strength of the material.

We were then shown around the straw bale theatre on site which has a timber frame structure and walls made of strawbale. The roof is supported by the frame

and a substantial amount of insulation is provided by

the walls.

We were made to understand why CAT chose to use

straw bale as a building material in particular:

it is a energy efficient sustainable resource which makes use

of agricultural waste products and is cheap and easy to build with.

However straw bale buildings require regular maintenance to

remain inhabitable and without this tend to mould, decay

or even collapse if not protected from moisture.

For the final practical we had to build a section of wall with two different thicknesses 40mm and 87.5mm with a large and small straw bale, after levelling each straw bale with a smooth and flat surface. Using a straw bale needle we cut the small straw bale to measure. We measured the length and inserted a stick at 40mm and tied a rope around the marked point, we used the straw bale needle inserting it on each side and split the straw bale at

40mm which was then fitted to the timber frame section.

We moved on to the large straw bale and inserted

a bale needle after measuring 87.5mm, we then tied a

long rope around the straw bale.

We used a saw to cut out the excess straw bale and fitted

the 87.5mm straw bale to the timber frame section

creating our straw bale wall.

The practical experience gave each student an understanding

on sustainable building materials such as straw bale and the

beneficial uses and high efficiency of the material when

applied to building structures.