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WhiteLotusLane

We have some land that needs to be raised some. The situation is like this:



So the land is not any lower than other land around it, but it's considerably lower than a road and small irrigation canal alongside it. It's about 1.5 meters below that.

While we probably won't raise the entire land area to the same level as the road, we should probably raise the area where the house is going to be by at least 1.50m and probably by 2m. (Does anyone know the typical cost to raise about 1 ngan or so by 2 meters?)

Of course the land needs time to settle, probably at least a year.

So I was thinking, would the following be possible: Put in the house footings at the current level and make the posts higher by 1.5-2 meters, then fill up the land afterwards so the footings are in solid soil, and go on from there? So like this:



As opposed to this:



Would the former be a lot more expensive, and is it worthwhile to do? Is the added cost just the extra length for the concrete poles?

splitlid

good questions mate,
the first method looks good but could be prone to a few problems, mainly with the back fill disturbing the foundations and or pushing on the columns,could mean your ground beams are difficult to place because everything has been pushed 'off square'.

other problems with such large foundation columns could be movement after the house has been built, or even by having so much concrete means more steel which could be prone to corrosion especially underground.

the second method also has problems, as the infill soil may not be settled enough and may result in movement again.

i would consider the use of piles and or spread footings on top of the piles.

Norton

Put in land fill first. Let it settle for a few months but not really necessary.

When it's time to build, dig footing holes deep enough (about 2.5 meters in your case) so footings are below old ground level about a meter or slightly less is ground if very hard. Pour footings and columns with appropriate steel reinforcement.

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cali kid

^^ The only way to properly do it...

ERIC

WLL,i would let the new ground settle for at least one rainingseason and then dig the foundation minimum one meter under the original level of the land,like Norton already said in his reply.
Good luck.

Happyman

Mr Norts has the best way !

WhiteLotusLane

Thanks!!

Fortunately, time is on my side as I will have to save some money to get anything built! Thanks!

Norton

I used the "land has to settle" excuse with the missus for 4 or 5 years.

Good luck when you do get started. The irrigation canal will be a boon for water supply. What part of the country are you planning to build?

WhiteLotusLane

Chiang Mai; about 30 minutes or so out of town. This is just for a garden/ weekend house, nothing fancy. We have a house close to town as well.

But yeah, plenty of water, pretty much year round. Apparently that particular canal never floods, but I'm not taking chances.

Norton

Canal never floods is a common phrase. Friend of mine bought a big chunk of land near Maha Sarakham right on the Chi River which "never floods". He built a huge house and last year the entire area around the house was waist deep in water. Was a Venice like experience.

BTW, a member here built some really nice "cottages" just north of CM. Might get some ideas.

This one is the main house.

http://teakdoor.com/building-in-thai...icefields.html (DrAndys Wooden Cottage in the ricefields)

This one cottages.

http://teakdoor.com/chiang-mai-real-...n-mae-rim.html (Charming Wooden cottages in Mae Rim)

WhiteLotusLane

Right, I know that. While THAT canal never floods, there is a river not too far away which does sometimes flood. (Though a lot of work is being done on that river to tame it). Either way, I am *expecting* floods. It's the Khan river which comes straight out o of the mountains. So in addition to raising the land, the house will also be on stilts with just a bathroom at the ground level.


Yes, I saw that topic. I think those are just a tiny bit too small, though also what I have in mind won't be as big as a typical rural house and MUCH smaller than DrAndy's main Mae Rim house. And any cottage will be raised higher, also to catch breezes & views and just because I like the style of a raised house on stilts.

This is a lot closer to what I have in mind, though raised higher up:

DrAndy

Thanks for that Norton! nice to be called a member in a friendly way

as for the OP, Norton has it right, fill the land and when you build, make sure your foundations are well into the original soil

most of the area around CM is floodplain, so the soil is clay. Just decent sized footings and columns are all that is needed (dependent on the house size), not piles.

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the dogcatcher

I put 1 nan up by 1 meter and left it 9 months. It cost about 1000 pounds and house ok. The piles for the house were sunk 2 meters with 9 baht and 9 leaves in each, no probs.

WhiteLotusLane

That sounds expensive.. That UK pounds? And at what exchange rate, 55 or so? So we're talking about 55,000 baht to raise one ngan by 1 meter? That's more than double of what I would expect (hope for). Or was this downtown Bangkok?

I thought it'd be something like 75-80K baht for a meter for a whole rai.

the dogcatcher

That's what I paid. erm, seems the going rate hear. Maybe I was stupid falang but Thais paying the same, you can never know.

the dogcatcher

This was Ban Phe, Rayong.