Choosing Roof Materials

Common Roofing Materials Compared

The most important part of any building is the roof, the roof keeps the weather out, it keeps us dry. There are many different materials we use for roofs and we must consider many factors when deciding what to use such as cost, aesthetic appeal, weight, resistance to strong wins and earthquakes. In tropical climates rainfall can be very heavy. Here we compare some of the more common materials used for roofing.

Alang Alang (thatch)

The people of Bali never had Wellingtons so they had to learn about dealing with rain. They followed a simple rule – get it off the roof as quickly as possible and let it run away somewhere. They built houses with floors above the level of the surrounding ground and used alang – alang (the tough broad leaved grass used as thatch) to roof their houses.

Thatch has been used for centuries of course. It can be easily sculptured to follow any roof shape, it has good heat insulation properties and is very rainproof. It does however have the odd disadvantage:

1. It sets on fire easily.

2. It lasts between 8 and 10 years (which may even be reduced if it is situated under tree branches).

3. Pests may live in it and it may start to drop nasty bits in your cornflakes.

4. In recent years good quality alang – alang has become even more expensive than roof tiles.

Alang – alang is still widely used by hotels, restaurants and expatriates who have warm and fuzzies about little thatched cottages but it has gone out of fashion for local people who these days tend to use hand made clay tiles as their roofing material of choice.

Terracotta Clay Tiles

The old roof tiles suffer from some significant problems.

1. They are hand made and vary slightly in shape so they don’t fit together as well as they might. Leaks are common.

2. They can be easily moved by people walking on the roof or a romantic cat out for its proverbial “night on the tiles”. (Did the tiles move for you my dear?)

3. They are fired at low temperatures and may break easily from such things as falling mangoes (or cats and dogs for that matter).

4. There is a shortage of good hod carriers in Bali

Glazed Roof Tiles

Times are changing. These days real estate agents don’t sell houses, they sell “homes”. Our materialistic lifestyle has given us ceilings, smart furniture, curtains, electrical appliances and fluffy toilet roll holders. Keeping the rain out is far more important than in the past. Roof shapes have become creative works of art that provide waterproofing challenges for builders.

As a result higher qualities of roof tiles have become available. They are more accurately produced from stronger materials, may have more intricate shapes so they lock together on the roof and are more water and windproof. You can even have shiny tiles in bright colours. The humble roof tile has come of age.

In addition aluminium insulation and membranes can be used under the tiles to increase rain protection, form valley gutters and provide heat insulation.

The cost of roof tiles varies according to the quality and the better the tile the better it performs. Basically you get what you pay for. A good quality tiled roof should last for many decades.

Your roof is your house’s first line of defence against cats and dogs and anything else that nature or little boys may throw at it. Once the roof fails a house can very quickly deteriorate.

If you are buying or building a house carefully consider your roof. If you prefer thatch, plan to replace it after 8 or 10 years. Make sure there are no trees overhanging it and make sure the electrical circuits are safe.

If you decide on tiles it is wise to find out what quality of tile has or will be used on your roof. Be aware that contractors wishing to improve profit margins may install a lower quality of tile than specified in contract documents. This can have a major impact in terms of house maintenance.

I recently saw a roof that has to be replaced after only 8 years because low quality tiles had been used. Resulting leaks have caused considerable damage to ceilings and roof structures.

Corrugated Iron

Other types of roofing are available. The humble corrugated iron is quick and easy and low cost. Corrugated iron can be very hot without heat insulation underneath it.

Corrugated asbestos is still around in some countries, avoid it like the plague.

Avoid flat roofs, as a couple of rather soggy clients of mine will testify, they can be a nightmare if not properly designed and built.

As a final comment if your roof is leaking get it fixed before damage is caused.