How To Install A Clay Tile Roof For A Bamboo Building

Tile roofs are one of the most durable roofing materials. They are, however, very heavy, even more so when it rains. This added load needs to be accounted for with a good structural design system.

Tile roofs work well for linear-shaped post and truss structures with a minimum roof pitch of 35-degrees. This material will not work well for organic and curvilinear roofs. Furthermore, the position of the rafters is key to the structural integrity of this roofing system. Rafters must be placed no more than 30 cm apart and battens must be added to hold the tiles over the rafters.

Every bamboo pole is unique. Each pole is hollow, round, and tapering with an uneven shape and the diameter of the pole ranges from base to tip. So, when tiles are used as a roofing material, it is crucial to check and balance the levels at every stage of the construction process.

There are 6 steps to follow to ensure the building is leveled before the final installation of the clay tiles.

1. Place your foundations in the right position, according to the design, and ensure raised footings are balanced. There are few ways to get the foundations in the right positions and all the footings at the right level. Start with marking a centre of a foundation point at one corner of the building and also add another mark by offsetting a few centimeters away from the foundation towards the outside of the building line using a bamboo lath.

The first foundation point as a reference, temporarily marks all the foundation points that are linear & diagonal to the first foundation point according to the design measurements. Also, add the mark point using bamboo laths a few centimeters away from each foundation point similar to the first foundation point. Now add a thread connecting all the linear foundation points tied to the bamboo laths to the height of raised footings according to the design and cross-check the thread height at all the footings marked with water pass.

It is important to get the perfect right angles and alignments for rectangular buildings by cross-checking the markings using the Pythagoras formula (a²+c²=c²).

Once the foundation points are fixed properly, then cast your foundations and raised footings using reinforced cement concrete.

If stone cappings are used over the raised footings as a moisture barrier, use a water pass to find the right level of all the footings with stone capping by adjusting the reference thread to the required height. Then adjust each stone capping over the footings to the levels right.

2. Ensure that the main posts for the structure are positioned at the angles detailed in the design using the reference of design measurements and a plumb bob. If this step is not done right, there is a high chance of the building being off-center.

If the design makes use of repetitive structural frames, the easiest way to ensure the main structure is level is to build all the structural frames on the ground using a template system and lift them manually, with a pulley or crane into place.

3. Add the ridge beam, and put the tie beams in place with temporary fasteners to hold structural frames together and diagonal struts to support the roof structure.

4. It is required to find the balance between the ridge beam and tie beams to get all the rafters on the same level. The best way to do this is to add the rafters at the corners and midpoint of the roof structure before fastening the tie beams, this helps to balance the tie beams concerning the ridge beam.

5. Wherever necessary, use bamboo spacers to adjust the bamboo poles to get the levels balanced.

6. The next step is to add all the rafters and then the roof eave & battens which help to hold the roof tiles securely over the roof structure. There are many different types of clay tiles available in the market, while placing battens it is important to consider the dimensions of the clay tile type that you are using for the roof.

The best way to get the batten levels right is to use planed bamboo splits to get rid of the internal curve of the bamboo pole and uneven edges from the splits.