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.....
