Wednesday, January 25, 2012

Timbrel vault first experiment

this is not a completed timbrel vault but a quick experiment. After a first try the second went better and then i started to get into it.

I used gypsum wall plaster. Have no idea if it is as good at pure gypsum, but once you complete there is no strength in the plaster anyway but opposing forces.

I would butter two ends, put it in place for like 5 seconds, then lightly lean a stick against it. then move to the next brick. building one more on each line at a time.

If you bang on it is like a drum, and i really bang hard on it.

I need to make one vault like this, then i put mortar between the next course and the third. I is supposed to be stronger than just a brick as thick as 3 thin ones. Like plywood.

Sunday, January 22, 2012

After Pointing inside, opening in middle?

We finished pointing last week. I think i will close up the apex. there is enough light and ventilation can be from the top of the walls.

Friday, January 20, 2012

Cantilevering the vaults out past the wall

thinking whether i need ties on the top bricks? The cantilever steps make the over hang 30cm.

Brick Railings?

Trying to decide if this is what I want to do for the veranda railing.

I need to add one column in that long run. It will have a ring beam where the bricks are standing up.

Thinking that I need a flower planter on top of the beam. Whole way around to keep people from sitting and falling off the back.

Wednesday, January 18, 2012

DIY sometimes is not good idea.

People get ideas from what others have done and decide they want something similar. But sometimes they might do something that needs engineering. This is the footpath gate between my residence and the brick factory and new vaulted house.

There are many arches in our house and some friends decided they need something a cool looking arch in their garden.

So they described to a mason and he built this:

It looks really nice . I asked the wife who supervised the mason ( ?) if they thought of the thrust on the walls? is there steel in it? It was some years ago when i talked to her about it and it is still standing. However structurally it screams at me, "WRONG".

Lets assume the columns are reinforced concrete in the middle, so the columns can probably hold the force of the arch pressing out, but it just bothers me.

I think i would of started lower on the arches and made them really steep and moved the arch right to the inner edge (springer) and maybe made the wall slope down and weight above the column and on the arch.

Mine has no reinforced concrete. the force is almost straight down because of the weight on the column above the bottom of the arch, and the semi -circle puts the force almost straight down anyway.

Masonry underground rainwater tanks

The people doing bio gas systems in the 1980's started making the bio gas digesters of brick domes. The Chinese came up with this system. Later I an others started making rainwater tanks the same way. Then i did a roof this way and eventually came to vaulted roofs.

Sunday, January 8, 2012

Would you build your outhouse out of stone?

Boxing Day I an on a ride and planing on snapping pictures of some stone masonry. I need a toilet and at a stone church high above Suji village I find this outhouse. I imagine there are a few westerners who would pay a mint for a rock wall in their million dollar house.

Friday, January 6, 2012

Masonry in South Pare

We took a holiday from Christmas to new years and while moving around i kept my eyes open for interesting masonry.

Pare and Usambara mtns are blessed with good stone, mostly granite. this below was easily quaried but there is field stone lying around. I drool over this pile.

The opening picture is this building. probably 30 years old. Clay/sand mortar, no ring beam.

Note a few stones sticking out, a few holes, and a board left in the wall.

Suji is a village bound by walls of a valley. there is no business but subsistence farming. So most people go away, make a living , visit at christmas, and build big houses. The one below is a famous family and this is the retaining wall around a three story house, reinforced columns and beams.

Chungkicha is 95 and he paid about 50 shillings to have this house made in the 1940's.
On this wall the sun, wind ,and rain have caused the clay/sand stucco to erode but the adobe brick are in perfect condition. A well meaning realative has plastered the walls on his veranda, and in some years there will be problems as the moisture wont gt out. One of the nicest looking small houses i have ever visited.

The next village over has less valley space and the road is cut from steep slopes. Extensive drystack retaining walls.

High up on the slopes on Suji valley is this church. No continuous lintel, just cement lintels over openings.

Not sure what the holes are for. Probably they put scaffolding on logs through wall. Also not sure why they do a thin layer of cement below window.
Very nice looking church. Even their outhose is made with granite stone and walls look great, wish the roof looked better.
At the foot of the mountains is the remains of this old school. They moved the school and took off the roof ten years ago and the walls are slowly eroding away.

Wonder why they didn't choose stone more and not plaster the outside. plastr was clay/sand and then thin layer of cement.

Despite having fantastic stones laying around this house is mud block, then plastered over with stucco. this house we own, and we will build a stone house with vaulted brick roof next door and take this house down. The stone will be granite field stone. the bricks i will have to find a way to make the bricks there on site.

In Suji you cant neglect this church.

My phone camera lacks quality, so trust me it says 1928. this is shaped stone probably 10 by 25 m with 4 m side walls. Quite impressive. Probably made mostly by German missionaries.