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.

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?

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. 

http://www.artmolds.com/ali/history_plaster.html
http://www.gypsum.co.nz/pages/product/kids.php
http://answers.yahoo.com/question/index?qid=20071207014217AAKIusG

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.