COST EFFECTIVE CONSTRUCTION
see also Simple Barrell Vault Construction
TINA'S HOUSE
Montecillo del Nieto, Mexico
Diana Armstrong's House
Her home is located in the country, 15 minutes from San Miguel de Allende. She was on a tight budget, so we were looking for quick and inexpensive construction. Two barrel vaults (each 6M X 3M) was the solution for the lower floor, which is built back into a hillside. The center wall is "artificially thickened" and consists of fat, structural pillars which join in arches at the top and form a closet, a fireplace space, and a large bookcase nicho down the center wall. The other low income house illustrated was built for the gardener of Bob Haas in Los Galvanes, Once again, two barrel vaults.
Low Income units, such as these, in Mexico typically cost about $25/sq. ft. (2005). The roof represents 15-20% of this cost.
Low Income units, such as these, in Mexico typically cost about $25/sq. ft. (2005). The roof represents 15-20% of this cost.
Construction of Affordable, Do-it-Yourself Housing
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 barrel vaults-- 2 on each floor
Bedroom and kitchen connected by bathrooms, closet, and 2 story atrium
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 barrel 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 barrel 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 alternative material), and start pouring the shell. This is as simple as it gets for concrete vaults.
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 barrel 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 alternative material), and start pouring the shell. This is as simple as it gets for concrete vaults.
FORMWORK
needed for each 4X5 M vault:
Cost of formwork-- less than $30/ vault, for the first 4.The formwork can then be reused an additional 50 times.
Note: with a little imagination you can use the same formwork for both, 4M wide vaults and 3M wide vaults.
THE LAYERS - bottom to top:
Note: you can pour the roof in sections. Start on Monday and pour some everyday till you finish to avoid "cold" seams.Waiting more than 24 hrs between pours is not recommended. Use pure cement slurry (neat cement) with latex bondo at daily seams.
needed for each 4X5 M vault:
- 10 each 2X2, 8 ft., pine
- 20 each 2X", 10 ft
- 33 sq. meters #6666 ww driveway mesh
- some nails and tie wire
Cost of formwork-- less than $30/ vault, for the first 4.The formwork can then be reused an additional 50 times.
Note: with a little imagination you can use the same formwork for both, 4M wide vaults and 3M wide vaults.
THE LAYERS - bottom to top:
- 2X2 pine--formwork*#6666 ww--formwork
- 26ga non galvanized plaster lath-- inexpensive in Mexico. (You could probably substitute plastic mesh onion sacks or burlap on top of reusable chicken wire, for this lath layer)
- 1/2" Shell-- 6 parts light weight aggregate, one part cement- volume
- #6666 mesh--it can be thinner than the formwork mesh or the same thickness
- 4-8" pour with light weight-- mixed 8/1
- 1/8" polish (the same day as pour, it sticks better and can be thinner)-- mix: 3 screened sand /one cement
- fill low sides of vault with loose aggregate, for second floor
- pour 2" flat floor for second story-- mix:2 lt wt.aggregate,3 sand and pea gravel,one cement--volume
Note: you can pour the roof in sections. Start on Monday and pour some everyday till you finish to avoid "cold" seams.Waiting more than 24 hrs between pours is not recommended. Use pure cement slurry (neat cement) with latex bondo at daily seams.
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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
formwork--( 4 at a time) $30 US
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 US
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:
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.
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
formwork--( 4 at a time) $30 US
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 US
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 Guanajuato, Mexico,
- $100/day = USA, hard labor
- 3 guys--3 1/2 days.
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.