House construction in Bangkok

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House construction in Bangkok

If you are dreaming of building a house in Bangkok, here is a little you should know about soil conditions and other things before you start.

The Gulf of Bangkok has not always been covered by water. Millions of years ago it was land, but the land sank and the bay was flooded. The area of Samut Sakhon in the west, Bangkok and Samut Prakhan in the east has for millions of years been a large river delta where the rivers Tha Chin, Chao Phraya and Bang Bakong have their outlet. These rivers bring large amounts of water down to Bangkok Bay up from the Himalayan mountains. In addition to sand, the river water has also carried sediments with it for millions of years. The sand and sediment remains have settled along the river and thus slowly built up a landlocked area. However, the Bangkok area is not done settling at all. The city sinks about 1 cm a year. However, it becomes 30 cm in 30 years.

However, this area is not very suitable for building on, but such is the whole of Bangkok. If you look at the picture here, you can see some different layers. At the top there is a layer of clay. It is 6-8 meters thick. Under this layer there is a loose sand layer which is 10-12 meters. Neither of these two layers is stable enough to carry a heavy building it will crack after a few years. Only down to a depth of 18-20 meters will you find a hard layer of sand that can support a building. This is the sand layer you can see at the bottom of this "grave"

If you only want to build a simple and cheap house, then the price for a pile foundation is too great. You see people make a load-bearing construction of 6 meter long poles. These are simply pressed down through the clay layer of a gravko, and in a group of 3-4 pieces form a point foundation. If it is to be done properly, piles must be knocked down to a depth of 18-20 meters, or until they no longer move at each stroke. They are usually delivered in two pieces, and when the first pile is knocked down, the second is welded firmly on top of the first, and it is knocked to the bottom. For a house of 140m², you have to count on 16 poles. I would recommend that you as a builder watch this part yourself, because if you break a pole down to a depth of 8-10 meters, it can not be used, but there is hardly anyone who tells you.

When the piles are knocked down, the concrete on the upper part is removed and it is braided into a point for the plinth. Here a box is cast that is about 70 x 70 cm. Everything must be reinforced and the house will rest alone on these 16 points. It is therefore important that this work is performed correctly. A construction of vertical and horizontal concrete piles is then cast, and the whole is filled with bricks or aerated concrete blocks which have become common in recent years. Personally, I prefer a brick, but it's a little more expensive.

Here are the boxes that are cast on top of the piles. The piles should of course be in the middle of the box, a reason to be there yourself and it is clearly marked where the piles should be.

During the construction of the house, it abounds with craftsmen every single day. In the last phase of the construction where painting is done, you should make sure that ALL drains are blocked. If they are not, then not much sand and paint residue is needed to block your drains. You will hardly notice it right away. These construction debris clumps together and partially clogs your drains. Many people think that you can get your brother-in-law or another good friend to keep an eye on your construction while you take care of your work yourself. Nothing could be more wrong.

There is no real vocational training in Thailand, so all the craftsmen are self-taught, some better than others. By the way, the best craftsmen I have had were from Myanmar ..! You should NOT expect your brother-in-law or whoever it is, have a broad knowledge of construction, be there yourself, or hire an engineer who supervises and reports directly to you. He must be completely independent of the construction company.

As I wrote at the beginning, areas here in Bangkok are sinking about 1 cm a year. A house on poles stands firm, BUT all pipes outdoors for water, electricity and sewer sink, 1 cm. per year. It is almost impossible to avoid them being torn apart, but little can be done. However, it just needs to be planned and implemented at the start of construction. Once the pipe is broken, then sand runs in the pipe and the drain is stopped

If I were to build today, these wells would have to be placed at each pile at each drain from the balcony. They would thus be part of the house and not the surroundings. It's a little too late to make once the house is built. It will then only be a couple of wells for sewage and toilets that you have to maintain the pipes on in the years to come. Water pipes should NOT be laid outside the house in the ground, they are the first to be torn to pieces and you quickly lose many m3 of water. In addition, it can be difficult to detect leaks. Faucets for garden watering etc. must be laid on the outer wall of the building.

Here is a drain pipe up from the balcony. It should of course have been embedded in the box of 70 x 70 cm and led out further down. That's not how it turned out. Him I had to look for did not at all have the knowledge that he expressed. Here I have had to rearrange the tiles along the house wall. As can be seen, they have sunk 10 cm. It took 10 years. In 10 years, it's wrong again.....

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