Land washing away around new home, 30cm holes opening up around the foundation

[chiman]

Hi everyone,

 

New build home in a moobahn.  Typical soil washing away around the home, being told its mostly going under the house to fill in the gaps around the construction debris and Micropiles.  

 

Was offered a plan to install a 40CM deep smart board skirt around the house, preventing some of the soil and dirt from going under the house, slowing down the erosion process?  Gut telling me thats not a good idea for now .. maybe let it fill up under the house for a few years?

 

Aside from dumping dirt each year, layering gravel, sand, soil, etc.  Is there anything anyone else has experienced that can help me understand what’s going on and how to address it?  

 

Thank you 

[sometimewoodworker]

You will loose at least 30% of the fill volume if the fill was completely compacted probably more likely 50% there is nothing that can be done about that apart from adding fill enough to allow it to compact.

 

This is not erosion but perfectly normal setting of disturbed soil

[Pouatchee]

I had to fill in 150 wah of my land. At first I put the sand/dirt typically used. The first year it almost all washed away. Eventually I started to fill in with rock and that solved the problem. On top of the rock I filled up with gravel and that made my land erosion resistant. My land is filled in over 2 meters in the rear of it an nearly a meter in front. That is a lot of dirt. I recommend you do the same thing. Rock is cheaper than I thought and since I used it no worries. It is not the rock that goes in concrete and unfortunately I don't have a picture. It is called 'hin pooh'. Shop around. Good luck.

Edited August 3, 2022 by Pouatchee

[unheard]

@chiman

"preventing some of the soil and dirt from going under the house, slowing down the erosion process?  

Gut telling me thats not a good idea for now .. maybe let it fill up under the house for a few years?"
 

A foundation built on columns?

Your house has probably been mostly constructed in the dry season.

Soil needs water to allow it to settle quickly.

You need to allow rain water to keep the soil around columns moist.

It shouldn't take more than a full wet season for soil to get compacted.

 

 

[sometimewoodworker]

20 minutes ago, unheard said:

It shouldn't take more than a full wet season for soil to get compacted.

My experience is that it takes far more than a single season.

[chiman]

Really appreciate the responses.  

 

Don't know if my house was built in the dry season, its a big builder, 1000s of homes near Bangkok.  They are building all year round.  Expect that they are cutting corners, the subs are a mixed bag.  Concerning (and expected) is all the construction debris left about 20CM under the dirt, I have found bottles, pipes, chunks of concrete, cans, etc.  

 

My gut feeling was that we needed to fill in that space under the house with rocks and give it time to settle.. now I see, that could take a few years of filling and settling.  This makes the most sense... maybe after a few years, then we could look at landscaping around the small bit of land around our house.  

 

 

[BritManToo]

1 hour ago, chiman said:

Concerning (and expected) is all the construction debris left about 20CM under the dirt, I have found bottles, pipes, chunks of concrete, cans, etc.  

You're lucky, I've got rubble/bottles/rubbish 2 inches under my soil.

5-6 years after my house build I was still filling in holes that appeared.

Edited August 4, 2022 by BritManToo

[Pouatchee]

1 hour ago, chiman said:

My gut feeling was that we needed to fill in that space under the house with rocks and give it time to settle

The rock on my land took very little time to settle. After I filled it in I used a tamper I bought to compress the rock down.

https://www.amazon.com/STKUSA-Vibration-Compaction-Compactor-Construction/dp/B07BSV8GLM

 

This looks nearly like the one I bought at Hardware House for 18 000bht well spent. If you want to do it do it right the first time. 

 

Good luck

 

Edited August 4, 2022 by Pouatchee

[freedomnow]

1 hour ago, BritManToo said:

You're lucky, I've got rubble/bottles/rubbish 2 inches under my soil.

5-6 years after my house build I was still filling in holes that appeared.

soon fill it up with all that weed debris they normally put in brickweed.

[unheard]

7 hours ago, BritManToo said:

You're lucky, I've got rubble/bottles/rubbish 2 inches under my soil.

5-6 years after my house build I was still filling in holes that appeared.

Sadly it seem to be a normal practice in Thailand, especially when the owner has no ability to closely monitor the construction site.

All various junk generated by the construction crew gets covered  by a few cm/inches of soil/sand.

They call it "site cleaning". ????

As the result the owner is stuck with a miniature landfill evenly distributed all around the perimeter of the newly built house.

I don't know if it's the main cause of the OP's problem though.

Edited August 4, 2022 by unheard

[sometimewoodworker]

On 8/4/2022 at 3:54 PM, unheard said:

Sadly it seem to be a normal practice in Thailand, especially when the owner has no ability to closely monitor the construction site.

It is normal practice in virtually every country I know of, one of the very few where it doesn’t happen is Japan.

[unheard]

2 hours ago, sometimewoodworker said:

It is normal practice in virtually every country I know of, one of the very few where it doesn’t happen is Japan.

Can you clarify?

Are you saying that construction sites in "virtually every country" besides Japan don't get cleaned up from various construction related trash?

[sometimewoodworker]

3 hours ago, unheard said:

Can you clarify?

Are you saying that construction sites in "virtually every country" besides Japan don't get cleaned up from various construction related trash?

Yes

Quote

It is normal practice in virtually every country I know of

That rubbish/rubble is dumped in construction sites.

 

Quote

one of the very few where it doesn’t happen is Japan.

Is that rubbish/rubble is usual normally cleaned from construction sites in all Japanese sites I’ve seen

[chiman]

On 8/3/2022 at 7:31 AM, Pouatchee said:

I had to fill in 150 wah of my land. At first I put the sand/dirt typically used. The first year it almost all washed away. Eventually I started to fill in with rock and that solved the problem. On top of the rock I filled up with gravel and that made my land erosion resistant. My land is filled in over 2 meters in the rear of it an nearly a meter in front. That is a lot of dirt. I recommend you do the same thing. Rock is cheaper than I thought and since I used it no worries. It is not the rock that goes in concrete and unfortunately I don't have a picture. It is called 'hin pooh'. Shop around. Good luck.

Any chance you have a picture of that "Hin Pooh" rock?  Cheers