How long to let land settle before starting construction?

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How long to let land settle before starting construction?

Postby somdet » Mon Aug 06, 2007 11:00 am

I am hoping to add about 30cm of fill to my property sometime in the next few weeks. How long should I let the land settle before beginning to build, if I have a dozer (not Dozer...) compact the dirt? Is 3 months long enough?
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land

Postby cruzing » Wed Aug 08, 2007 3:28 pm

Somdet,

30 cm isn't much fill, is there any reason you can't build on terra firma? Your house would be much more stable.

I've seen them preparing land in BKK to build on and running a dozer or truck over it isn't going to compact it enough. You will have settling. Of course the houses in BKK are built on piers, but the driveways etc. are not. We've seen lots of driveways, walkways etc. drop in different parts of the city from a few inches to a foot or more.

The house next to us was built over a filled in lily pond. They had dirt brought in etc. and let it sit several months before building, but I notice the driveway has settled about two 1 1/2 to 2 inches by the gate already.

Besides building on terra firma, maybe Jazzman has some compacting ideas for you if you think it's necessary to fill first.

chok dee,
Cruzing
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Postby somdet » Wed Aug 08, 2007 4:03 pm

Hi. Yeah, the land is below the level of the street and my wife, who grew up with flooding in her village, is absolutely adamant that we need to raise the level of the dirt at least above the road's elevation. Thanks for the advice and warnings.

By the way, I just checked out your house yesterday- Wow! that is a very nice pad. I have a question about your crawl space- How do you lay the cement slab on top of that?
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land

Postby cruzing » Thu Aug 09, 2007 11:20 am

Hi,

Yes, I understand her concern. However, we had the same problem at the front of our land by the road, but only brought in fill dirt for the driveway area.

If you do a a crawspace type foundation you can go ahead and build on terra firma and backfill later......that's how we did it. We have a crawlspace that is from 1 to 1 1/2 meters high. My husband wishes he'd added another meter and just made it a basement for storage, workshop etc.

A few of our friends are building their houses with basements, one just across the canal from us. More like a garden basement.....half in and half obove grade so you can have nice windows.

Anyway, on your question about the concrete floor. Go to my photo gallery and click on the construction album. See the one that have the supporting walls for the subfloor??? two or three pics I think. Then it shows the subfloors. These are high density concrete planks....ours came several attached together, that are put down and then you pour your floor. I think I have more pictures. Let me know if you'd like to see more.

If you are in the Pattaya area let me know, I'm sure my husband wouldn't mind showing the crawlspace to you. One advantage to that also is all your plumbing and electrical can go under the floor and you have easy access to it. Several of the homes in the housing resort next to us have crawlspaces also..........even building thai style.

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Postby jazzman » Sat Aug 25, 2007 11:51 am

Somdet,
A thread exists already and some of the info you need is here:
http://coolthaihouse.com/forum/viewtopic.php?t=643
it might help.
30 cm is not much and your piles or foundations will of course go much , much deeper. The in-fill will not be serving any structural purposes at all except maybe as the 'formwork' for your floor and footings. If your footings are designed correctly (and there is no reason why they should not be - the architect will have included enlarged details on his drawings) for keying in the floor, they and the floor will support themselves when the concrete has cured, which is what they are supposed to do.
Thai builders usually pour a 10cm thick floor. Some engineers suggest more. If the floor is any thicker, it is probably more prudent to use rebar rather than the wire mesh.
If the floor is expected to remain in contact with the dirt, it is a good idea to put PVC sheeting on the dirt for what is knon in the UK as a 'damp proof course'. Another useful move is to include nam ya - waterproofing additive - in the concrete; the quantities aer very small and you can treat all your CPAC with it for just a few hunndred baht.

There will always be extra footings running under the floor in any places which are expected to support interior walls.

The floor in Cruzing's house is an excellent solution for building on very humid dirt or even over water. It is a similar construction to that of an upper storey and is very strong. It also contributes significantly to the passive cooling of the house.
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Re: land

Postby thomas.fontaine » Mon Jan 21, 2008 9:51 am

Cruzing

your solution with foundation + crawlspace and back fill as required afterwards is definitely the best solution in my view. This is what we did for a house in France.

Do you know if this is a usual method in thailand or do I have to spend hours with architects and builders to convince them this is the right way to go?
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Re: land

Postby cruzing » Mon Jan 21, 2008 2:54 pm

thomas.fontaine wrote:Cruzing

your solution with foundation + crawlspace and back fill as required afterwards is definitely the best solution in my view. This is what we did for a house in France.

Do you know if this is a usual method in thailand or do I have to spend hours with architects and builders to convince them this is the right way to go?


As a rule, no.....however, like I mentioned before they did do about 50-100cm crawlspaces on the thai style houses next door. They did not build on terra firma however, so don't know how it will be for settling later on as the land was all former lily ponds.

If you get a builder that has a little curiosity and genuine desire to learn something new, you shouldn't have any problems. Mr. C. finally told them that for the footings for the crawlspace, that he was putting the beams in the ground........use the ground as forms for the concrete. Of course with re-bar.
One note on re-bar here; they will over kill with the re-bar, which in this case more isn't better, in fact it will weaken your footings.

cruzing
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Postby jazzman » Mon Jan 21, 2008 5:01 pm

Commonly known in France as a vide sanitaire. Poses no specific constructional problems, it's basically the in-fill without the in-fill - just the same as building a house on the same columns but just raised a little. Either use formwork for casting the floor slab, or pan peun - pre stressed concrete slabs.
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Postby thomas.fontaine » Mon Jan 21, 2008 5:37 pm

Jazzman, I can see you are very familiar with french. I have some trouble sometime to find the right technical wording for thing in english.

As discussed under an other topic, could you explain the connection between your foundation and the ground floor for a design with no piles and no crawl space (vide sanitaire), I just don't see how the ground floor is connected to the foundation (on top of a short pillars network?)
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Postby jazzman » Mon Jan 21, 2008 5:55 pm

Houses are usually built here on a gridwork of reinforced concrete beams (poutres) which sit on the short pillars that come out of the foundation holes.
See this:[url]
http://coolthaihouse.com/cthpics/displa ... um=6&pos=2[/url]

and this:
[url]
http://coolthaihouse.com/cthpics/displa ... um=6&pos=3[/url]
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Postby jazzman » Mon Jan 21, 2008 5:57 pm

The beams and the pillars are cast in one go to enable a contiguous framework of concdrete.
The extensions of the pillars are them cast in formwork boxes like this:
http://coolthaihouse.com/cthpics/displayimage.php?album=6&pos=20
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Postby thomas.fontaine » Mon Jan 21, 2008 7:56 pm

OK, that's crystal clear and very different from what I could see back in France.

If you fill your land before starting your construction, you have to dig a bit deeper afterwards for your foundation but you can use the added dirt to support the beam formwork while it is curing. That made me change my mind.

Thanks for that.
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crawlspace

Postby cruzing » Mon Jan 21, 2008 7:59 pm

Actually you don't have to jack around with poles in your house. Besides us all our friends that are building are building without any poles in the house. The exterior walls are supporting the whole roof, unlike where you just have poles. you have none of those supporting poles in the middle of your rooms....you can knock out all the interior walls if you wanted to.

Just make a jig and build regular trusses..........they're all built on the ground and installed. Doesn't take a lot of man power........then you can attach your ceiling right to the bottom of your trusses. Either drywall or those panels Jazzman is in love with. :D Whatever floats your boat.


[url]
http://coolthaihouse.com/cthpics/displa ... um=6&pos=3[/url]
This is better than the regular post and beam, but go one step more and
you don't need to use concrete blocks to make your footings (beams) , just dig them in the ground. We have 60 1/2 m X 1/2 m pads under our house with the footings (beams) dug in the ground between. put in rebar and concrete and you're set to start laying your block for the crawlspace.

However, we wish we had added 1 more meter and just made a regular basement. Wouldn't add a whole lot as far as building costs.

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Re: crawlspace

Postby thomas.fontaine » Mon Jan 21, 2008 8:07 pm

This is exactly what we did in France. I think I quite understand the pros and cons of any of the 2 methods now. And this was my objective: understand what is going on.

I will probably let my Architect/Builder chooses the method the is comfortable with.
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Re: crawlspace

Postby jazzman » Tue Jan 22, 2008 8:55 pm

cruzing wrote: Either drywall or those panels Jazzman is in love with. Cruzing


What panels :?: If you mean pre-stressed pan peun, I n ever actually used them myself :D
Just seen them around a lot.
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