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Construction
of Affordable, Do-it-Yourself Housing
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Bill's
House
One
of my current goals is to develop a low income house for the 3rd (or 1st)
world that is easy to build from local materials and that will last 200
years. Photos are of a moderate income house we're doing for computer
Billy. He built this web site.
THE
HOUSE
3 bdrm, 2 bath, 55 sq.M each floor
4 each, 4M X 5M barrell vaults-- 2 on each floor
Bedroom and kitchen connected by bathrooms, closet, and 2 story atrium
FORMING
SYSTEM
The idea
here is an inexpensive, reusable formwork. Three guys (gals) can set the
formwork for a 4M X 5M vault in 2 hours flat-- the second one,anyway.
WOW!! If you want an inexpensive vaulted/domed roof--- my system could
give you some ideas.
Tip: drive
8d nails with tie wire, pig-tails into your lt. wt. vertical wall blocks
at 1.5 M height from floor ( will vary), to tie in the sides of #6666ww
barrell vault formwork. Drive 20d nails (or pieces of 3/8" rebar)
into the wall blocks above the formwork to grab the pour. Stick up the
2X2 pine, then 26 ga. lath (or aternative material), and start pouring
the shell. This is as simple as it gets for concrete vaults.
FORMWORK
needed for each 4X5
M vault:
THE
LAYERS - bottom to top:
THE
WALLS
10-25cm
thick --Block made of the same lt. wt. volcanic aggregate. 10/1 cement,
vibrated. Poured, hard concrete, reinforced, vertical, pillars every 3M
aprox. Reinforced bond beam at top of walls, tied to 2" thick, second
story floor. Foundation and wall costs are best calculated on site.
ROOF
COST
6" (15cm) thick 4X5m vaulted roof in Mexico
| |
$US
|
| formwork--(
4 at a time) |
$30
|
| 33
sq. M #6666 mesh |
60
|
| 33
sq M 26ga plaster lath |
30
|
| 5.2
cubic m aggregate@$18/m--6" / 15cm, thick |
100
|
|
cement--(6/1 mix) 20 each 50kg bags X $8.00 |
160
|
| materials
for polish |
40
|
|
labor-- form work, pouring,and polishing, 3 guys X 3 1/2 days
|
180
|
| design
help---5 hrs. @ $20-----me |
100
|
| |
|
| Total
for roof , Mexico |
$700
|
Note: Cost per sq. M , not finished on the inside= $35/M or $3.50/sq
ft Note: we're still pricing out these roofs so some of the above may
change-stay tuned.
Note: on
labor cost per worker:
free =you (and your 2 brothers-in-law)
$20/day=skilled,hardworking,Gto MX,
$100/day =USA,hard labor
3 guys--3 1/2 days.
I'm assuming a power mixer and laddering buckets up to the roof with
humans.The second roof should be faster. Once you eliminate the design
fee, this is an economical roof.
ROOF THICKNESS
Six inches is good for the final roof in mild climates. Four inch vaults
are adequate for the first floor vault that will be filled on the sides
and have another floor above.
R-VALUE
It all depends upon the aggregate you use. For a fluffy pour with my aggregate
I claim 2 1/2 per inch, but I don't know for sure.So 6" is about
R-15.Properly used solar gain messes with R values and R40 ceilings may
not be necessary with this material even in cold sites.If you find you
want more insulation, mix and place another 6" next year. Folks at
the ferro group (see Links) are working on other materials because they
don't have the good aggregate available locally.
BUILDING CODES
A lot of places here in Mexico we can do engineering on site-YIPPE !!
That freedom is changing fast, even here. Vaults should be an easy structural
shape to calculate and get stamped. I'm currently looking for programs.
LINKS ON THIS SITE
More on low income
roofs - http://www.geocities.com/flyingconcrete/lowinc.htm
Roof forming - http://www.geocities.com/flyingconcrete/Forming.htm
Some ideas for underground
barrell vaults - http://www.geocities.com/flyingconcrete/cellar.htm
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