Wednesday, September 05, 2007

Rammed Earth In INDIA

This is home was designed by Chitra Vishwanath Architects for Nishwath Hassan and Prakash Iyer, a Bangalore-based couple in their mid-30s. You can see more of this firm's wonderful work at and read more about this project here.

A. Slipform construction. Formwork is made from prelaminated plywood and mild steel angle sections to reinforce it. The formwork allows for 1 foot by 4 feet blocks.

B. The mud blocks are used as end panels here instead of having any formwork at all.

C. The formwork and how it's supported in place.

D. The walls are 9" thick. They have sufficient self weight to not need any other attachment or reinforcement. There is a nice rich mud mortar between the plinth beam (there's a beam above the stone foundation) on which the bricks rest and then the rammed earth. The bricks or mud blocks can be optionally done away with. The self weight of the wall structure is sufficient to hold it in place. In India we always have built in brick, stone and cement and reinforced cement concrete. Except for the roofs, beams and concrete columns (if there are any) steel is not used to reinforce walls. Our structural engineers say it's not necessary. The load bearing capacity of the RE walls or any walls is dependant on their own strength and by self weight they hold well in place.

E. Tamping walls by hand.

F. Scaffolding made of casurina poles.

G. Form work for RE in place.

H. Granite lintels.

I. That's the stone foundation made from locally available stone andthe rammed earth first course above it. One single course of mud blocks are first laid so that the skirting of the flooring can go overit without cutting off the rammed earth.

J. One can see the Jack arch roof/Arch panel roof between the rammed earth walls. The basement is 3 feet above the ground level to bring in ventilation. The soil that was excavated from the basement was used to build the house. It was mixed by hand with sand and 5% cement then transported without the use of machinery. The only steel reinforcement is in the Jack Arch ceilings. We have vaults made in the same Mud blocks in the house too, which do not need any reinforcement. These structures are all designed and validated by senior structural engineers. We are in seismic zone two.

K. This is the same rammer used on the walls.

L. The formwork for the corners in the centre of the photo. Just prelaminated plywood with Mildsteel angles to reinforce it. The walls here seen are of the stabilised mud blocks. They take the same mix as the rammed earth only are pressed using a manual machine.

M. These are the natural colours of the earth, no special pigments required.
N. This effect is created by ramming into a formwork of logs!

O. The finished house from outside. We design houses to suit their immediate climate. Its very important that we rely on external sources of energy least. Appropriate lighting and ventilation is necessary. Too much light would heat a structure quickly and too much air would be difficult to control during winters. Its important that the design makes way for hot air (vertically up) and brings light into the right parts without using humungous openings. Helps in controlling cost of structure too.
These Ecological homes that we make are cheaper than the conventional designer homes in the same city.

P. To the left of the door a bench upon which to sit and remove one's shoes. Cubbies beside for shoe storage are made of pipes put in place with Mud plaster and some mud blocks which are covered in mud plaster.


Q. View of a typical stabilized mud brick and rammed earth house from outside, a different project than the preceeding. The larger blocks are Rammed Earth Blocks. Meaning that the blocks were made aside and then placed like bricks. This was the first experiment with RE of the office. The mud mortar became necessary in this case as the blocks were bonded by the mortar. The stone used for the compound wall is a local stone that's found in nearby quarries in Bangalore.

R. The basement. The ceilings are made from 2 inch thick clay tileswhich are pre-cast with a little cement and reinforcement and placedon trusses or beams to make the ceiling. Above its filled up withplastic and such waste and with a thin layer of concrete to give the floor above _____?

S. The court inside and the steps that lead into the basement. We propose basements in our houses because that added earth that comes from that excavation can be used to make the rammed earth and the mud blocks we've used.Totally following the "cradle to cradle" theory.

Tuesday, September 04, 2007

Tall wall / wood form

Here are some construction shots from Nk'mip in April of 2005.

Wood formwork, pipe clamps, walers, strongbacks with through ties.

$60 a sheet for form ply, it's a shame none of this got re-used.

I wonder what our friends in India make of our abundant use of lumber and machinery?

Notice the form ply running wild on the left side.

Some kind of pipe clamp / through-tie situation here. As I recall the rest of the wall was done
with a different solution. Further investigation of the archives is warranted, obviously.

No chamfers on these edges, just crisp, crumbly corners.

Dont forget to reinforce those utility boxes!

The very latest in rammed earth formwork technology

Here's a link to a project our pals at Solum have underway in Penticton:

Those are some fancy aluminum forms!

Monday, September 03, 2007

Photos for Friends

A reader asks for more details of bracing formwork. We are happy to oblige.

It's hard to ram under things that are attached to the formwork.

This device allows us to plumb the formwork by adjusting the angle of the brace.

Once sand and gravel start flying they can work behind the waler board, obstructing firm, even pressure and effecting the finish of the wall. Some masking tape along the boards can help keep the mix out.

That's a strongback with wedges keeping those walers tightly in place.

Hope this helps.