An Autoclaved Aerated Conrete block or lightweight brick, is essentially concrete with lots of little air pockets. According to Wikipedia, AAC was invented in the mid-1920s by the Swedish architect and inventor Johan Axel Eriksson. But it only became a popular building material world-wide in the 1980's. To me, it looks like a rectangular block of hardened meringue.
The wall - notice the size of the normal brick sitting on top of the wall
The wall separating the house and the back-lane is being rebuilt using this material. The reason for using this "brick" over conventional clay bricks is the need to lighten the load on the site. Indeed, these blocks are light - scarily light. The wall swayed when I touched it while it was being built, but thankfully stiffened when the concrete columns were erected later, effectively bracing the ends of the wall.
AAC blocks will also be used for all the walls dividing the rooms. Because they have so much air in them, they are very effective thermal and sound insulators, perfect for hotel room walls.
Laying of ground-beams are underway. As of today, the ground-beams for the kitchen/toilet area at the back of the house have been laid.
ground-beams for the toilets & kitchen area
Ground-beams function as connectors between pile-caps. (and pile-caps are concrete blocks that sit on top of the piles) In a site where the ground is soft, there is a high risk of uneven settlement amongst the pile-caps. So, what the ground-beams do is that they "tie" the caps together to stabilize the foundation and minimize uneven settling. The workers are currently laying the beams in the studio/gallery section.
moulding for the ground-beam in the studio area, waiting to be filled with concrete
Look at how high the water-table level is - sitting just below the pile-caps. After a recent bout of monsoon rains, the water level rose up to about a foot and a half below floor level. You can gauge the water level from the ground-beam at the back section. It looked like this:-
after the rain
the architect's vision
Originally, the 3-storey extension at the back of the house was to sit on a foundation of concrete piles. But we switched to using bakau piles after discovering there was only one piling contractor in all of Malaysia with equipment compact enough to enter the site. He was going to charge me over 3x the normal mobilisation cost, probably because he had a monopoly on the market. I wasn't about to spend the amount he wanted, which was almost a quarter of my budget. So, bakau piles it had to be.
bakau standing by
It turns out that bakau wood is an extremely suitable piling material for the soil conditions at Malay Street, and has been traditionally used in the area as a material for laying building foundations. As the area was reclaimed from what was originally a swamp, the water table is very high. This allowed the piles to be perpetually immersed in water - a pre-requisite condition for ensuring bakau - or mangrove - doesn't rot. Also, the 'soil', being composed of marine clay made it easy to drive the piles in using only a backhoe.
the backhoe, ready to go
I learned that bakau piles are called "friction piles" because the piles are suspended in the clay by friction between the pile and the surrounding clay - rather than resting on rock or a hard surface at the bottom. Its as if the clay were gripping the piles like a hand would.
bakau piles for one column, ready for capping
This would work out well. Except that the weight of the building had to be reduced. So, we scrapped the green roof and changed the concrete stairs at the back to one of steel.
pouring concrete to cap the pile
Its been over 2 years since my last post. During this time I had been busy applying for planning and building permissions from the city council.
This was my first time ever having gone through such an extended bureaucratic process. And I was totally overwhelmed and floored by the reality of its own caricature. Its a long story, better told over bottles of wine. Suffice to say the process confirmed the long-held belief that the civil service is from another dimension where irrationality is a way of life, and any attempt to engage with them would suck you into a deep psychotic morass that is potentially inescapable. Inevitably, my experience reduced me to a ball of quivering jelly, incapable of anything except scream with popping blood-shot eyeballs "I WILL COMPLY!".
When the approval letter was finally issued in June, 2011, I didn't even dare to feel relief, fearing a second letter from another department to follow informing that I had left out something or other and therefore was not in compliance. Thankfully, it remained a nightmare.
The wall - notice the size of the normal brick sitting on top of the wall
