The Ideal "Puna" House Design

[bjbTay]

David,

Insteresting....is the Hardie Panel 5/16" 4x8 for $28.00?

I received a quote from HPM for the 5/16" as follows:

4x8 $30.48
4x9 $34.29
4x10 $37.75

Barbara Taylor




Hawaii Dreaming

[David M]

Barbara. Didn't check thickness, but it was the Sierra pattern. Definitely 4X8.
Be aware that prices often change when new deliveries arrive.

David

Ninole Resident

[Hotzcatz]

Not old growth, per sae. From what I understand it is recycled bridge timbers in this particular house. Rough sawn dimensional 1" x 12"s. Not termite proof at all, knots and splits all over the place. There is either a batten or some metal sheeting nailed over the splits and knots, but the boards aren't clear. Board and batten inside and out. It isn't one of the manager's houses, it is a worker house and an old one at that. Still standing, though, and likely to keep standing for quite some time. If the lumber is kept dry that goes a long way to preserving an old house. Keeping any other construction method dry would help it's longevity, too, for that matter.

A lot of folks have been using 2" thick T & G vertical siding lately, which is similar to this type of construction although almost double thick so even if the newer wood isn't as good, it is still almost twice as thick. If folks could mill up local trees and use them for building their houses, it would be a much more sustainable method of house construction. Cheaper, too, since generally they will mill trees in exchange for part of the lumber.

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"I like yard sales," he said. "All true survivalists like yard sales."
Kurt Wilson

[bjbTay]

Originally posted by David M
Barbara. Didn't check thickness, but it was the Sierra pattern. Definitely 4X8.
Be aware that prices often change when new deliveries arrive.

David

Mahalo David. You also just reminded me I didn't specify smooth finish, which is what we want! Thanks again, Barbara

Hawaii Dreaming

[john the architect]

Barbara,
I work with Rob Tucker and appreciate his dedication to helping people have better homes that will only have to build once. I design with metal studs and hardie board, among other systems, and our own home in HP is built with no structural lumber and no drywall. The contractor who said earthquakes will bend a steel home apparently never visited our four story, steel, concrete, and IMP home in central HPP. After the big earthquake when all the neighbors lost power, we had an undamaged home with plenty of power (photovoltaic)
and cool drinking water (integral Castelblock water tanks built into the base of the structure). Building well takes more planning, requires some inventiveness over the "business-as-usual" method, sometimes a little more initially on materials, but is extremely satisfying when you can sit back and enjoy it with piece of mind.

quote:

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Originally posted by bjbTay

Originally posted by David M
Barbara. Didn't check thickness, but it was the Sierra pattern. Definitely 4X8.
Be aware that prices often change when new deliveries arrive.

David

Mahalo David. You also just reminded me I didn't specify smooth finish, which is what we want! Thanks again, Barbara

Hawaii Dreaming

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[Youser]

John

Can you give us more information on building materials and designs - e.g.

Do you build forms and pour concrete for walls?
Do you use the hardi board as siding or instead of drywall?
What material do you use for roofs?
What do you do near the ocean where rust is a problem and therefore anything metal is at risk?

I am interested in strong, sustainable design and would like more information.

Thank you.

[john the architect]

Youser,
I wish my students asked as many questions. But here you are:
-Forming concrete in the traditional way is expensive and difficult, the reason why ICF construction (the original Castleblock material) is so popular. It also makes concrete construction a DIY process, with a certain amount of set up, basic tools and guidance.
-Yes
-The most expensive I can afford. Depending on whether it is catchment or not, and covers living or sleeping spaces. Tin-aluminum coated corrugated metal is the cheapest decent material.
-Stainless steel (careful, there are grades of this and it takes the high grade) or composites/polycarbonates.

[MarkP]

Some have said that they prefer a single level slab on grade for ease of accessibility. I respect this viewpoint but still think that it does not address the original question. Many traditional house designs in the tropics are basically up on stilts. There must be reasons for this, and some posters have already stated some good reasons. I am trying to get at the meat of the design challenges for the tropics and for Puna in particular. So far:

1. Elevate house enough to get shaded air space underneath. Storage too if you make sure the house will stay standing in an average earthquake.
2. Draw air from underneath, through house and out near peak of roof for good chimney effect.
3. Big roof overhangs to keep sun and rain off.
4. External lanai for extra dry living space when the weather is good, which is most of the time, and somewhere to stand when it is raining. I heard that you can screen in and partially enclose a lanai and it does not count towards the square footage of the house for tax purposes.
5. Hip roof because it stands up to hurricanes better than simple gable roof. That is the theory. Some people say that hurricanes hardly ever hit the big island but I have seen fallen trees on my property that seem to have all fallen in the same direction.
6. Large open-able doors and windows to take advantage of cross breezes. Not good for security though.
7. Reflective light colored roofing and a little insulation or radiant barrier to slow the solar gain down. I am assuming metal roofing but is there a reason ceramic tiles would be better? They have an attractive Spanish look but they are heavy. They seem best suited to desert environments with no earthquakes, although you see lots of tile roofs around in Hawaii. Like adobe, they came from somewhere with big temperature swings and clay to make them out of.
8. Basic structure: Wood has traditionally been used and it stands up to earthquakes very well. Wood makes it easy to build the house on stilts design. Wood will always have a maintenance burden due to rot and termites. Adobe is out. We got too much rain and earthquakes and not enough mud. Reinforced concrete or concrete blocks could substitute for adobe, would withstand the average earthquake, and would last a long time with little maintenance. Concrete would not be good for an elevated house design though.

So many trade-offs. If you think a tall chimney like structure is best it would be hard to beat wood for ease of construction plus the necessary flexibility and strength to weight ratio during an earthquake, but the longevity and ultimate strength of masonry is very attractive. I heard that many houses in Guam are like CMU bunkers because of the hurricanes. I know their telephone poles are twice as thick as ours are. I don't want to live in a bunker but I hate the thought of my house being ripped apart by a storm.

[JWFITZ]

Most places in the tropics where hurricanes are a persistent problem traditional structures are often have large planted stands of timber bamboo to shelter the house in such conditions. Here locally the "hirose" type would be a good choice and will get to 60 or so feet. The idea is that the bamboo blows over on the house and literally buries it. Since inland the major risk isn't having a house blown down but the roof destroyed and then the house filled with 20 inches of rain--the bamboo buffer trick is about as good as any, save welding up a plate steel roof, I guess.

[bewitchedinhilo]

Look at nature, bee hives and animal mounds. CMU decagon, poured concrete corners/ fly ash added, #4 rebar every 16" both hor & vert, door or window on all walls but 3, rafters to a compression ring, standard 1/2" ply and shingles and 4/12: Last earthquake, a little wiggle in the chandelier, winds up to 170 mph are channeled over and around!