Preparing land to build

[Handsome Man]

Hi everyone, hope you are well.

My Udon wife has some land in a rural area north of Udon which we are preparing to build on. As you can see from the attachments, we got the soil heaped up and I was told it will need to settle for about 2 years before putting down a foundation and building our home. These pics were taken about a year ago and on a recent visit I noticed that the land seems to be crumbling around the edges and I am a bit reluctant to build unless I am absolutely sure that there won't be any issues with soil erosion that could sooner or later undermine my investment. Does any of you Udon expats have any experience in this type of build?
Cheers,
Paul

[Khun Paul]

Build retaining walls...simple answer

[BillaRickaDickay]

Assuming your missus owns the surrounding paddy fields.
Retaining walls expensive and looking at the height of your backfill would eventually fail, step the backfill, retain the top level for the house, terrace the garden.
Piled foundations, Precast concrete floor slab, could start building straight away after some test bores and a professional structural engineers foundation design.

[Whistler]

Planting on embankments is worth considering, plants with wide spreading roots can be very effective and attractive too

[Handsome Man]

Thanks guys for the useful tips. Yes, have started planting out Whistler so hopefully that's a good starting point. Retaining wall sounds good Khun Paul, will have to speak to a structural engineer to discuss BRD's suggestion that they may fail over time. Will also have a ride around and see if retaining walls have been used in the area for similar builds. BRD, by 'stepping' do you mean something along the lines of what I did at my place in Oz, where I had a high bank prone to erosion (see below)? If so, I probably don't have room to do that on two of the four sides as it would encroach onto the neighbouring properties.

Thanks again for all the tips guys,
Cheers,
Paul

[Khun Paul]

People dismiss retai ning walls as too expensive, however over the years have seen those with NO etaining walls later having to shore it upbecause the weather and the rai erode the ground. Planting does help if you chose the right plants , but as we allknow plants to develop their roots enough to retain the slope take some time.

So basically horses for courses, as low wall with excellent reinforced foundation , raised so far then as time progresses can be added to over the years to maintain the soil wih intruding into the overall look and views.

[BillaRickaDickay]

Looks like you've been there before Paul.
Retaining Walls? Obviously the higher you go the more prone to failure, I'm just going on your plot photos, more steel, more concrete. Piled columns/posts + pre-cast panels seem to be the current trend.
All down to your budget I guess.
Lots of stuff on Google about retaining walls, lateral forces etc
Anyway, good luck with your build, I'm still at it 10 years down the road.

[sometimewoodworker]

Hi everyone, hope you are well.

My Udon wife has some land in a rural area north of Udon which we are preparing to build on. As you can see from the attachments, we got the soil heaped up and I was told it will need to settle for about 2 years before putting down a foundation and building our home. These pics were taken about a year ago and on a recent visit I noticed that the land seems to be crumbling around the edges and I am a bit reluctant to build unless I am absolutely sure that there won't be any issues with soil erosion that could sooner or later undermine my investment. Does any of you Udon expats have any experience in this type of build?
Cheers,
Paul

1) you can build on it as soon as you like, but your foundations will probably have to go down to the original level.
2) 2 years is not enough time for the ground to compact for the foundations to be in the fill.
3) if you want you can get a soil bearing test done, the universities will have a side businesses doing this

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The report is like this

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With our build we did not need to go to the pre-filled level.

FWIW unless you are a Thai national you don’t technically have an investment
For erosion control follow individual number 9’s recommendation and use Vetiver Grass https://tvnwi.org/what-is-vetiver-grass/ we did, it works

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[Whistler]

I built house in Australia with a substantially filled block. Piered down to the original level with reo columns, used drop edged beams and a wafflepod foundation. Never had any problems with a very large 5 bedroom, two story house with oversized ceilings (Ie very tall walls). It was expensive.

[Handsome Man]

Blown away by the helpful responses from all, and thanks so much sometimewoodworker for taking the time and trouble to put those pics, report and links together. sometimewoodworker, as you said the foundations need to go down to the original level, could those foundations support a slab that sits on top of the raised soil?

[Handsome Man]

I built house in Australia with a substantially filled block. Piered down to the original level with reo columns, used drop edged beams and a wafflepod foundation. Never had any problems with a very large 5 bedroom, two story house with oversized ceilings (Ie very tall walls). It was expensive.

Thanks Whistler. Yes, half of my build site in Oz was also on filled soil but I didn't have to wait two years for the slab to get laid, so I'm assuming the nature of the local conditions in Udon, along with different methods of building locally would kind of make what I did here not relevant to Udon? Cheers, Paul

[sometimewoodworker]

Blown away by the helpful responses from all, and thanks so much sometimewoodworker for taking the time and trouble to put those pics, report and links together. sometimewoodworker, as you said the foundations need to go down to the original level, could those foundations support a slab that sits on top of the raised soil?

You can support a slab on foundations there is no problem, however you cannot rely on the raised soil to be of any support.
Treat the fill as air and you will have no difficulty.

I suggest you look at the 394 posts on the “Workshop and house, Non Sa-At ½ way between KK & Udon” thread on CTH
There are many other threads that could be useful