So I saw some post and pier forms for sale...

[maggiethecat]

I saw this for $300.

http://honolulu.craigslist.org/big/mat/719925443.html

Worth buying them ready-made or are they easy enough to make by ourselves? $300 seems an awful lot for some forms...Any links to form construction guides?

-maggie

[glenn kangiser]

Would be hard to say if they would suit your needs or not, maggie.  John's plans come with post and pier information on the plans that can use them and here is generic post and pier information John posted for free.

http://countryplans.com/foundation/index.html

[maggiethecat]

Hi Glenn there are foundation plans for the GC as well? Thanks. I didn't see it listed on that link.

--maggie

[glenn kangiser]

John only posts the generic one.  I checked the GC plan set for you and it is designed to use only a perimeter footing -- all around concrete with only 3 post and piers in one section or a concrete slab on grade with integral footings or a floating slab between the footings.

John would have to tell you how it may be possible to use a complete post and pier foundation or if he recommends it.

If you have questions on it you could PM him.

[mvk]

Maggie

I have never seen that pier detail, and if you look around the site I don't think you will see any here. If that's what you need for code over there then they might be worth it.

Looking at that picture it's hard to see if they are sitting on the surface or if the are underground and what depth. If they are on the surface say they are 12" deep. It looks like you have 2.5 sheets of 3/4" plywood, and depending on how they are built you could have a couple of hundred feet of 2x4. What would that cost over there? If they are deeper you would have more material. If you could sell them later that would be another consideration.

From their description it seems that you would still be short the little forms? the one's that look like they are maybe 16" sq.

Do you know if you will pour them with ready mix? Then you would need to form and pour the whole job. If you where going to do it your self then you could get by with less forms and take them apart and put them back together for the next one. You can pull them apart after a day if you are careful maybe less if it is real hot. Then it might not be worth it.

Mike

[John Raabe]

The forms on craigslist are probably an engineered design for that specific project. They are not what is normally done for P&P foundations. The L-shaped corners may be designed to support shear walls and provide earthquake or hurricane bracing (one of the limitations of P&P foundations). Since you are in frost-free land (HI) the footings can be relatively shallow. Just down to non-organic bearing soil.