RE: Pier Depth

[Wao nahele kane]

Dennis - You should have no issues with a post and beam atop a rafting pad system. I would at the same time also point out that an alternative turn down footing pad foundation will save you much money as well provide you with a naturally cooler floor surface and that’s something to consider also. Just for G.P. In lava, the rip occurs when a dozers single claw is forced deep into the lava by wobbling the tractors load with the claw deployed against the lava surface and then when driven down below the surface it's used to rip through it by advancing forward and or tilting the claw forward and backwards. Rolling is when the larger lava fragments are driven over by the heavy dozers steel tracks crushing it into smaller lava rubble making it more gravel like in nature. Hence ripping and rolling, this also serves to collapse and crush any subterranean voids that may otherwise succumb to a house load atop them inducing foundation failure. A D-9 or like type Dozer has the weight to flesh out these problematic voids and crush them, essentially removing them from the sites equation. Sometimes in Aa a lighter dozer may be used and the area simply rolled to save $ on the dozer and its time. In the end, your Engineer or Architect should call the shot.

Mr. Bill - Ultimately your foundation will rest in the hands of a licensed Engineer regarding the matter but I would say if it's your desire to build in that manner, than your engineer can make it happen and all should be fine. Sounds to me when you span a crack you're citing a grade beam type foundation also perhaps serving as a drag strut across the cracks? On pahoehoe lava, I personally like less ground coverage by concrete and dislike disturbing the natural grade in an area depending on the subterranean conditions, though it's not always practical - it's my preference for aesthetic purposes. I would caution that a 30" concrete wall/beam will interfere with natural air flow under your house if it becomes a full perimeter type. I would not advocate the use of any sort of full perimeter stem wall foundation in the Puna region, it's just asking for floor system issues regarding fungi and pest issues.
If you're just putting in a single grade beam/wall, ventilation should be fine.


E ho'a'o no i pau kuhihewa.

[Wao nahele kane]

Dennis – I missed your reference to ICF… how would you incorporate that into the design of a Ranch style if you’re intending to raise the house? I’m not sure what you mean there.
Are you going to use air conditioning in the house?
I have a bit of an issue with homes that are not air conditioned or heated but use sheetrock, insulation and conventional framing in Hawaii. The reason for this is simple - it's ventilation and air quality. Cavity type wall construction creates dead air space cavities and moisture will eventually prevail - promoting mildew if the home is not properly maintained air quality wise through heating and or cooling procedures. Mainland home construction evolved about energy issues should be tossed out the window in Hawaii if a home is not heated or cooled.

If a person isn't going to heat or cool a house in Hawaii then they need to make a breathable house. This is best achieved with a single wall constructed house, consisting of a basic frame or a post and beam/timber frame type with intermediate stiffeners for an exterior siding that has its back exposed to the interior of the home. There should be floor vents in each room allowing exterior air to flow into the room with upper wall or ceiling vents to promote a natural draft throughout the house in each room.
Single wall construction offers far less expensive finish procedures and materials too, trimming a load of building costs from the home. Not to mention the beauty and warmth that can be achieved far exceeds a conventional mainland home using sheetrock finished walls. Often each framing member can be sanded, stained and clear coated becoming part of the finish interior of the home. Wood need not be an issue in Hawaii if used properly.

There’s a little secret when finishing wood framing intended to be used in a single wall home. By using water based stains one can add sodium bicarbonate/NaHCO3 (baking soda) to the stain effectively fireproofing the finish lumbers. If a clear coat is applied, the clear coat may be combustible (just like paint on sheet rock) but the surface of the wood under the clear coat will no-longer fuel a flame because the sodium bicarbonate impedes the oxygenation process of the wood attempting to be burned.


E ho'a'o no i pau kuhihewa.

[mr. bill]

Wao nahele kane- thank you for your input on my post. Point well taken on the full parimiter foundation wall. What do you think about 4' X4' corners with beem pockets and 2' sections spaced at ?' depending on the size of the ridge beem? Pax

I'd rather be fishing "WITH BAIT"

[Wao nahele kane]

Pax,
I'm not really following your description. If you’re referring to a post and beam/timber frame home... They are perfectly fine and if the home isn't to be heated or cooled I'd recommend them over a conventional energy envelope fabricated home when in Hawaii.


E ho'a'o no i pau kuhihewa.

[mr. bill]

Wao nahele kane- I'l try to splain this a little better. Structure parimerter 24'X28', foundation/footings 4ft.X4ft.X30in.highX8in.wide poured in place reinforsed concrete on undisturbed pahoehoe, thus the four corners. A 2 or 4ft. section between corners on the long side. Atop all that a 4X12 or double 2X12 rim, across with 24ft. 2X12s or I joist and up with a conventional light frame casa. Put lava rock vaniere on the foundation walls (Eldarado Stone makes a good one), and twa-laa. Hard for me to explain anything without a fat pencil and a scrap of plywood. Still there will be pukas running under the house?

I'd rather be fishing "WITH BAIT"

[Wao nahele kane]

Bill,
The dimensions of the concrete foundation described aren't making sense for me.
If you sketch it up - you can send it to me via e-mail if you like.

E ho'a'o no i pau kuhihewa.

[Wao nahele kane]

Just for GP here's some examples from some recent things I've been working on.

Here's a pier based structure that is pinned to the rock it stands on, a view based guest studio designed for use on Buck Mountain on Orcas Island, San Juan County, Wa. -
http://farm5.static.flickr.com/4041/4184...f3f3_o.png

Here's an old original design for our house in Hawaii that we scrapped and uses footing and column *Note; there's no rafting pad used, this is because of the concrete 12"x30" suspended rafting beams at floor level well above grade and they act to provide shear (resistance to lateral loads - earthquake and winds) between the columns and with the floor system installed between them, it keeps the columns relationally fixed to one another -
http://farm5.static.flickr.com/4037/4184...0734_o.png
http://farm3.static.flickr.com/2591/4183...a9a9_o.png
http://farm5.static.flickr.com/4008/4184...2839_b.jpg
http://farm3.static.flickr.com/2739/4184...85b8_b.jpg

Here's what we're settling for now and it's a mix of turn down footing slab on grade with footing and column supports on the upper envelope extrusions. With the exception of two column footings the remaining column footings are tied via a simple rafting pad-
http://farm5.static.flickr.com/4006/4184...8c38_o.jpg
http://farm3.static.flickr.com/2721/4184...3ff7_o.jpg
http://farm3.static.flickr.com/2724/4184...9066_o.jpg
http://farm5.static.flickr.com/4002/4184...3d7b_o.jpg

There are several other types of foundations not shown above.

Just to make it clear incase some-one is about to flag the chosen exterior products on the house design we ended up choosing. There's no wood, it's a cladding composed of a product similar to Richlite countertop material but Made by Klip Tech and it's called EcoClad with a simulated Walnut Grain veneer over a bi-composite board.
The rest is polished and brushed SS with corrugated SS or perhaps Galvalume or we'll just use common steel corrugated unfinished and allowed to rust for a couple years until we have it treated and then sealed.
http://www.kliptech.com/ecoclad.html




E ho'a'o no i pau kuhihewa.

[mr. bill]

Wao nahele kane-Thank you for your time and interest. I will make a simple sketch to convey that which my convoluted words failed. Thank you for shareing the great renditions. You sir, obviously did NOT (just fall off the tyrnup wagon).

I'd rather be fishing "WITH BAIT"

[Wao nahele kane]

Bill,
"Put lava rock vaniere on the foundation walls (Eldarado Stone makes a good one)"
With so much lava about the island, why not just pick up a nice Ridgid 10" wet tile saw down at Home Depot and cut your own? That way you're not limited to a single color of lava nor are you limited to the lava finish type. We're planning on cutting our driveway pavers from lava and doing a mosaic layout (yes it will take forever but... it's Island time; no?)

E ho'a'o no i pau kuhihewa.