[GSBN] Lightweight concrete roofs

[Derek Roff]

Hi, Mark,

Thanks for your information.  I would love to hear you say more about 
this part of your posting:

"It sounds as though there is plenty of resources for the mix so I 
won't address that too much now...it's not rocket science. You 
basically use the latex as you would water for a cement mix with sand. 
You can use as little latex mixed with water as seems effective..."

That "as seems effective" instruction sounds like it could require a 
lot of experimentation to get right.

I would also like your opinion on inverting the hyperbolic paraboloid 
roof elements, as shown on the Green Building Elements website. 
<http://greenbuildingelements.com/2010/06/14/new-habitat-approaches-build-roofs-first/>. 
The examples in Albert and George's book have the peak at the center of 
the roof, while the above site has flat ridgelines, which give the roof 
a look similar to two intersecting gable roofs.  I can imagine 
advantages to each approach, but I think the latter look would be 
acceptable to more people in more cultures, and it makes water 
catchment much simpler.

Thanks,

Derek

Derek Roff
Language Learning Center
Ortega Hall 129, MSC03-2100
University of New Mexico
Albuquerque, NM 87131-0001
505/277-7368, fax 505/277-3885
Internet: derek at unm.edu


--On Monday, June 21, 2010 8:47 AM -0600 MARK SCHUENEMAN 
<huffnpuff at q.com> wrote:

> Greetings All interested parties,

The 'Nez' Roof system has certainly progressed beyond the experimental 
stages. The are many roofs around the world thanks to George and Al 
Knott. The reason George didn't return your email is probably he just 
returned from training folks his roof system in Uganda where they did a 
roof for a performing arts center. I know there's Nez roofs in 
Afghanistan, Kenya, Rwanda as well as many other working demo 
structures in the Denver area and the mid west US. He has trained his 
roof system to many folks , including myself, and we've built the 
system many times around the world. His model of 'roof first' makes 
sense. He was working with a minister in Afghanistan after their 
earthquake when all they had was tarps. Snows would collapse the tarps 
when they could have built his roof with mostly salvaged materials and 
used the tarps and more salvaged materials for walls. Recently he's 
been in conversations with some folks in Haiti, so he could get you in 
touch with them.

George is a wonderful man with a vision and plan and energy abundant 
for a Ninety year young fellow. Mr. Nez started doing disaster relief 
work for the federal Government in Central America years ago. He has 
always been more than happy to share his knowledge with anyone 
interested. As a matter of fact, you may want to make a pot of tea for 
a conversation with George. He is a most knowledgeable resource when it 
comes to disaster relief. If you have a project going somewhere I'd 
guess George is a suitcase packing away from joining you for a demo of 
his roof system, as would I, or to discus your project.

His system is more about the shape of the structure and the latex 
coating but the 'fabric' for the roof has been an evolution. He used to 
weave a fiberglass netting for the latex parging but has worked with 
and tested regular old cotton fabric (or even tarps) with chicken mesh. 
These materials seem more readily available in most parts of the world 
and cheaper. The frames can be made of salvaged materials and spliced 
effectively. The latex for the concrete parging can be old left over 
(or oops) paints, if you can live with the color. It sounds as though 
there is plenty of resources for the mix so I won't address that too 
much now...it's not rocket science. You basically use the latex as you 
would water for a cement mix with sand. You can use as little latex 
mixed with water as seems effective...more latex (50/50) to water for 
the initial coat. I can attest that the system works well and can be 
low cost. It is easy to learn and quick to build.

The latex parging seems very durable, flexible (elastic), waterproof 
and enduring. The material itself is not that difficult to work with 
other than that it doesn't lend itself to a great esthetic. My guess is 
that if you're homeless, cold or hot and wet, you could care less about 
esthetics. Once you apply the parging with a few strokes of a brush or 
trowel further strokings only drag, ball and/or tear. I got some on my 
vehicle and missed cleaning it until the next day and when I removed it 
some paint came with it...it's sticky. Clean your tools soon and often.

If interested please feel free to write myself or George 
geonez at peoplepc.com or call me with your thoughts or inquires.

Regards,
Mark Schueneman
303-444-6027 hm.
303-591-9841 cell