1. The land to be built must be hard (not soft) soil, so that there is no subsidence.
The land to be built must be ensured that the soil is strong enough to withstand the burden of the building on it starting from the load of the foundation, sloof, columns, ring beams, walls, roof construction and other parts such as ceilings, doors, windows, and water tanks. In normal soil conditions, it means that the soil is hard enough, if it is dug around 80 cm, it has reached hardness. It is sufficiently marked by the weight of the hoe
If the soil is soft or unstable, even though it has been dug deep but has not yet received enough violence, it can be overcome by installing a trucuk (wood that is stuck to the ground about 3 meters deep, to strengthen the soil and foundation on it). This method is commonly done in the Kalimantan area, the people there use ironwood to make it reach hard ground. After that, then the foundation is built on it.
2. The foundation should be made strong, not too save material because the foundation is the bottom of the building that serves to hold the load on it.
The foundation for the most widely implemented residential is the foundation of natural stone, can be river stone or mountain stone. The shape is made of a trapezoid with a width of about 30 cm, a width of under 50 to 80 cm depending on the weight / lightness of the building above it and the condition of the soil. If the soil conditions are hard enough, then the width of the foundation is 50 cm for the first floor of a normal house.
If the soil is soft, then the choice of foundation is replaced with a foot plate made of reinforced concrete. For a 1-story house with a size of 80 cm x 80 cm thick 20 cm, it is felt strong enough to withstand the load on it.
3. The structure of poles, beams, horses must be made strong so that if there is an earthquake it can still withstand shaking.
The structure of the building starts from the foundation, sloof, columns, ring beams, horses all must be done properly, both the size of reinforced concrete cross section, the use of the main reinforcement, ring / beugel, how to bind, concrete mix, the implementation of casting should all follow the instructions that exist . Staple both for sloof, column, ring beam and palm foundation is recommended to use 12 mm diameter iron and the ring using 8 mm iron with a maximum distance of 20 cm.
But in reality, a lot of them only use 10 mm iron, and even then the size is not standard. So many are just putting it up for savings without thinking about the bad consequences if an earthquake occurs. For beugel, many also install 6 mm iron with non-standard sizes.
Actually it could have used a 6 mm iron but the maximum beugel distance was 15 cm. Another thing to consider is the meeting between sloof and sloof as well as columns with sloof or columns with ring beams. It is highly recommended there is a crossing or 40 x diameter reinforcement to get into other parts.
This condition is the least considered by the public. Generally only just entering as deep as 15-20 cm, so that if there is horizontal movement from the earthquake resulting in the relationship detached. At the bottom of the column, iron should be put into the foundation as deep as 40 x the diameter of the main reinforcing iron. If you use 12 mm iron, then the entry is 40x12mm = 640 mm or 64 cm deep. The entry of iron can be bent like the letter L.
4. Walls must be made of wall material that is resistant to impact, stirring to install and plastering is quite good, for example comparison of 1 cement: 5 sand. The function of the wall is only limited to insulation, because the load has been received by the ring beam, column, and forwarded to the sloof / foundation.
5. The horses must be made of good wood, not fragile, not too small in size. The horses are not only riding in the ring beam but should be tied tightly with iron construction or at least bound with bent iron columns nailed to the wooden horses.
If you use mild steel, choose one that has good quality, because there are more than 60 brands with mild steel quality. Make sure the installation of light steel horses is done by a certified applicator and the construction is planned with the correct statistical calculations.
6. Doors and windows have to be anchored so there is a strong bond with the wall. If an ordinary house is enough 2 anchors on the right and 2 anchors on the left, then a sturdy house is recommended at least 4 right and 4 pieces on the left side of the frame.
7. The quality of water pipes and electrical cables are also selected good material is not easily fragile and torn by the age of the building.