Friday, December 28, 2012

Parallel brick vaults

Progress on the third house.

While there I noticed the family has moved into the long vault.  I wanted to see about dampness especially but talked to her about 15 minutes about the house, efflorescence, ventilation, and the like.  She said she was very happy with the house.  I was surprised that they were no longer seeing any dampness on the inside.  she asked about the white efflorescence .  I told her it would just fall off and not touch or wash it.
She says that about 8 pm the house warms up for a coupe of hours.  that is the heat stored during the day.  They keep windows open until about 9pm.  I told her to put plants up on the roof to shade it.  We talked about having planters and growing spinach and the like.  I must say that short visit paid much back of the unpaid time I have spent on this.

A short video showing how to glue a brick in the vault.

Stone walkway

Not sure what to call this stone. It is quarried near my house and use to make crushed gravel and used as hardcore under foundations and floors. Some of it is stratified. All of it is hard but somewhat brittle. I had put in broken 1/2 bricks and the like on the path around and into the house but it always looked dirty and uncleanable.

So i bought some chisels and split some of the stones and shaped some more and came up with this stone pathway over the timbrel vaulted bridge.  next two the bridge I put up two columns and a rough cut reject lumber beam.  Bernice wanted another place to put her flowers.

Thursday, December 6, 2012

Venting the vault

Will take a picture, but this is something we are putting in now, vents on the top of the endwalls. We moisture is not escaping and rooms can get stuffy.

Another style

The next house in progress.

This is more what I envisioned for the widow's houses.  Will start laying the vaults on next week.

This way the forces in the two internal walls are almost canceled, it would of been better if all the rooms were the same width.

Remember the cracks?  Well after considerable talking (and feedback from some of you)  we will this time put the arch over the wall with 1 cm of clay/sand mortar.  After we are done with all the arches we will dig this mortar out.  The reason being is the arches laying on the wall are not "settling" the same as the arches freestanding.  We believe that is something that is causing some of the cracking.  Later we will fill that gap with something flexible.

Matt, Jeff, Sean and others :  what do you think?

Saturday, December 1, 2012

Timbrel Vaults, mortar material for first layer

I am not an expert on timbrel vaults, but this is what I am doing. 

The first layer of thin bricks or tiles on a timbrel vault is laid generally with little or no form work.  This makes it cheaper, faster, and xxx than just a brick vault. (It is also stronger)

So what does one use for mortar , a mortar that is quick setting, cheap, and available.  It doesn't add any (or much) structural strength to the vault, it is only for holding in place until a complete arch is made.  Many arches are side by side the strength is in compression.  Well on a timbrel dome it would not be an arch but a horizontal ring being completed then gives the strength, not until last piece is in place. 
I use gypsum plaster, or plaster of Paris for "gluing" up the first layer of the timbrel vault.  I go buy the gypsum plaster you use to plaster walls in a house.  for me it costs $10 a 20kg bag.  It is NOT a local material it is imported from Thailand, England , etc

I am not sure what exactly Gaustavino used.  The beginner on searches will come up that they used gypsum,  but this is gypsum that has been heated to 150C and then ground.  this is plaster of Paris.  In brief, you heat it up, the water is removed as steam, you grind.  When you need it you mix with water 3:1 and it sets within 15 minutes and hard in 30.  It has returned to gypsum now.  It needs to be kept dry to stay hard.

I just discovered that I should recycle my plaster of Paris .

I use clay/sand mortar to stick up brick on brick vaults.  What could I do to make clay work on the same?

What about modern cement additives to make a quick setting plaster?

what about adding some fine sand with gypsum to make it cheaper?

anything else I don't know about.

Next topic:  How do you make the tiles stick with gypsum plaster without holding for a long time.  Guys in Spain stick them, tap them and they hold.  they are adding the next one in less than 30 seconds.  I tend to have many rows going , giving the last one a bit of time to dry.

Friday, November 30, 2012

Why aren't Timbrel Vault people like Linux Users?

 Why aren't Timbrel Vault people like Linux Users?

Say what?

A bit of background so this question becomes clear to the reader.  In my past life I managed a bunch of  network equipment, mostly Linux servers.  Not a handful, I mean like 50 of them. 

I started to install and learn Linux before there was Internet in my town.  In fact I needed to get a Linux server (  and a Cisco router) running before my town could have Internet.  It is a long long story,  suffice it to say that someone helped me in an email get going,  and then once a Linux server running I then had access to tons of discussions and FAQs about issues I was having with Linux and presto the question was already asked and answered about umpteen times.

  That started in 1997, and by 2000 I was hiring young people to help me manage the servers at the ISP and the 50 servers at clients premises.  During the interview a key question was, "what do you do if you are faced with an error or something is not working on one of your servers?"  Of course the answer is " I would google the error".   If you could google and read you could install and fix anything.  People were enormously helpful without thinking about charging.

I benefited , and yes I also participated, from this incredibly helpful community.  If I needed to setup a new service, say squid caching server, there were many HOWTOs and then when I was stuck on something, the same question was answered already, or someone or even crowds of hackers would come to my rescue.   it might even be one of the key people who made the particular software or application.  To this day I am amazed how helpful the Linux community is to one another.  It happens with Cisco users and other groups but not to the same extent.  Linux users will spend considerable time making step by step instructions, share the results, and refine them. 

So now back to building vaults. 

As you may have noticed I became interested in masonry vaults and domes a few years ago.  I started with domes where there are many masons in my locality with that skill.  I moved to Nubian vaults where there are some websites, to brick vaulted explained somewhat by auroville.  Eventually I have come to timbrel vaults where I looked at pictures on other vaults.

These sites were helpful in a passive sense.

But unlike the Linux world no one takes the time to make a step by step process and leaves allot for the newbie vaulter to work out himself.  Or at least I have not found details on timbrel vaulting.  And if you ask a question on email , well I have never received a reply.

Contractor Talk moves in that direction, but not with vaults.  Maybe the the pool of vaulters is too small?  Dry Wall builders are much more helpful and document much more.

Timbrel Vault stairs III

Dickson got some steps on the vaulted stairs in between jobs.

I am a happy camper.  I have been delaying the top part of these stairs for years.

Saturday, November 17, 2012

Catalan vaulting in Cuba

This is one of the most remarkable examples of catalan vaulting.

Imagine it was never used.


Thursday, November 8, 2012

Timbrel stairs - II

The temporary plywood sidewall was carefully removed. Dickson now can easily glue a line on both sides. You butter two sides with gypsum plaster, put in place and tap , hold a few seconds and then repeat. Better if you can have two lines going so it sets up a bit. Also we leave the plaster to set for 5-10 minutes before using.

Below  sees after three layers are in place.  the side will look better after pointing.  The courses all have different bonds and overlap joints.  It feels like a cast reinforced concrete slab.

Cleaning up some plaster. 
It is a bit hard to get perspective, from below looking up  the run to first floor. (second floor to Americans)

From the top looking down.  It would be better to have joints in the middle, but these are thin bricks and cutting makes them a bit weaker.  and it is covered of course.  I walked up the vault.  feels more solid than a full single brick in shiner orientation.  I mean it feels very solid, like i said like a reinforced concrete beam.
Now we let it cure a bit and put some treads, but not the final treads as we can't keep them clean.

Monday, November 5, 2012

Timbrel Stairs

The crew have been busy at Kisongo with the Widow's hall and houses (two now) since May.  I got Dickson to add a mason and finally I got Dickson back full time, on the groined vault house for awhile.  ( While the other mason Goodluck puts up the short walls on another vault in Kisongo.

I finally bit the bullet and went ahead this week with a "new" technology for me.  Timbrel or Catalan Vaults.

Where I want to use this technique is on the top half of the stairs in the groined vault house. Where the brightness is up to the top floor.  

I made a post about this technique, and I tried some trials and found the gypum plaster works for the first layer.

I know how to do timbrel vaults  but the catenary shape can vary, so I kept putting it off  and off and fretting about it.  I bit the bullet a weekend ago and traced the shape on some reclaimed chipboard.  The load on the arch will vary so I worried about that until i realized when someone is standing on it it would also change the line of thrust so i figured at any time the LT will stay within  1/3 of the arch.
So here is from the side, the first of the three layers. tomorrow we remove that chipboard.

Below is the view from below.  After removing the side "wall" we will add another row on both sides. the plywood is our template and we use that wall to "glue" the tiles.  We need more suport.

And what it looks like on top of the arch.
As I said we will add two layers on top of this one, different bonds, and then the treads sit on top of the vault. The mortar now will be cement-lime-sand.  Each layer is overlapping the bond below.  Should be fun.

Edit 7 November 2012:
This is a good link about Timbrel vaults.  It explains more and better than I can.

You too could have a roof/ceiling like this in your house.

Wednesday, October 10, 2012

I have interesting development.  See that crack?  this will get technical.  Hope I can explain it.  I am not too worried, but in the future would like to change the overhanging vaults.

In the picture below you can see that outside the walls I stepped out a horizontal brick and then made vaults on top, then again and agin.  This allowed me to get a 30 cm overhang over my walls.
This vault was finished 10 months ago.  We put a waterproof cement/sand plaster on recently.    Same as the widows meeting hall.

Now both buildings have small cracks  as you see in the first picture, all in the middle of the wall and ending in the vaults above the wall.  Not every one, and only two go into the brick and then not all the way through.

Most tend to crack where the brick is stepped out in the midle of each side.

the stepped out vaults add weight and further down and so change the line of thrust
-The plaster behaves differently than the bricks, and it is very thin, so the line of thrust could move out of the plaster
-the wall makes different dynamics.

Any thoughts?

Long Vault closed

The vault is closed and the "lunette" door and window turned out nice.
Dickson and Godluck are putting on a scratch coat, with some weld mesh in three long lines.

Kind of funky door from outside, the inside is more in keepting with the spirit of vaults.

What the ceiling of entry way looks like

Friday, October 5, 2012

How the groined house started

It is a long story, about deceit and lost hopes, about dreams and failure, etc , etc.

There was a chance we would have to move away from the house i had lived in since 1987. It was about 1995. So I started building this house. This part was to be the garage/workshop with bedrooms above with wooden floor.

the kitchen and bath would be behind and then eventually living room and more bedrooms in a kind of "wing"
It sat like this for years.

Then I stumbled upon vaults, then groined vaults, and history was made.

Thursday, September 27, 2012

Long vault again

Going pretty fast.

Middle room will have a door and window breaking the vault.  The door will be a vault coming out 50 cm.

Friday, September 21, 2012

Bucket List: Arched Bridge

On a vacation a few years back in the Amani Mountains (sometimes called East Usambara Mtns)  we liked the place and ended up buying a few acres and this house at a price we couldnt pass up.  There is a spring down in a steep ravine. 
The problem is we need a bridge.  We have another plot further up the river and here is the bridge to get there.
Up by the house I have been collecting these stones, to make an arched bridge over the river in a narrow spot.  I want to make a stone arched bridge before i kick it.

Long Vault continued

The internal walls finished early last week and the vaults started. this is a start but still not what i envision as the cheapest way to build. I would rather 3 vaults next to each other, rather than a long one.


The other end room.  Dixon has picked up another mason. 

Apologies about the camera.  I like how they closed the last gap with bricks the other way.

Sunday, September 9, 2012

Long Vault progress

As mentioned we are building a 10m long 4m wide vault starting at 80cm height.  NOT how I wanted but it is work for dickson.  two openings in the middle room breaking the vault. 
dickson thought we could do the whole distance but it proved to bring issues so he will do all four walls.