Bamboo Roofs: Everything You Need to Know (Pergolas Too)

Have you ever been outside in the summertime and noticed how cool it feels to be under a canopy of trees?

Perhaps you’d like something like that over your home, patio, or pergolas? Bamboo roofs may be a perfect addition to your home if that’s the case.

Bamboo roofs are a sustainable and eco-friendly approach to roofing. Unlike conventional corrugated asbestos, zinc, and plastic roofing panels, bamboo roofs are cooler in the sun and quieter in the rain.

They are ideal not only for your house but also for outdoor living spaces like pergolas.

In the rest of this article, I’ll discuss everything you need to know about bamboo roofs. I’ll cover how bamboo roofing compares to other roofing systems and whether they make good roofs for pergolas.

Let’s dive into the world of bamboo roofing.

Is Bamboo Good for Roofs?

Bamboo is good for roofs because it’s environmentally friendly, sustainable, and possesses excellent insulation properties. Bamboo fibers have a thermal conductivity of less than 0.082 Wm⁻¹K⁻¹, making bamboo an excellent insulator for roofing.

Using such a material for the roof helps control noise due to rain and protects from higher temperatures in summer.

A point worth noting is that bamboo will not make an excellent roof for your home if you don’t use the specific roofing systems that work for bamboo. Using conventional roofing techniques to install a roof with bamboo exposes your structure to the following:

• Water leaks
• Insufficient insulation
• Structural damage caused by the weight of the bamboo roofing system.

There are five roofing systems that work well for bamboo. They include:

Thatch Roof

As the name suggests, thatching involves using dry vegetation like water reed, straw, and rushes to form a roofing layer. The vegetation is usually woven together and covered with a protective coating of clay or mud.

Bamboo can eliminate the use of mud and clay protection when building thatched roofs. Instead, dry grass is folded over a bamboo split to make thatch panels of at most 3 meters (9.84 feet). The panels are threaded onto the split using palm fiber.

Besides protection against elements like wind, bamboo split gives structure to the grass and reeds to form a sturdy layer of thatch roofing.

Thatch roofs are used in areas that experience high rainfall because they offer excellent protection from rain. Thatching also helps increase the insulation properties of bamboo roofs.

For the best performance, the roof’s pitch should be about 45 degrees. This pitch angle ensures that water can run off smoothly without stagnating on the roof. It also helps reduce the chances of moisture buildup in parts of the roof.

Moreover, you shouldn’t install the rafters more than 60 centimeters (23.62 inches) apart as this can cause the roof to sag.

While thatch roofs are common in tropical countries, using bamboo splits for the structure helps make them more robust.

Although these roofs can keep the indoors cool, they require regular maintenance with replacement every 3 to 7 years.

Split Bamboo Roofs

Split bamboo roof, also known as halved bamboo roof, is the most common type of bamboo roofing.

This type of roofing involves splitting the bamboo culm into two halves and arranging them in an overlapping pattern.

The overlapping bamboo splits help stabilize the roof and protect it from strong winds.

The technique used to install halved bamboo roofs is similar to Spanish tile roofing because the splits are threaded onto the roofing system one after another.

Split bamboo roofs possess excellent insulation properties, making them an ideal option for tropical countries where temperatures can rise to extreme levels.

The overlapping technique also helps keep out the elements, making split bamboo robust all year round.

For the best performance, a split bamboo roof needs a pitch angle of at least 40 degrees. Moreover, the rafters must be at most 60 cm (23.62 inches) apart.

The only downside to this bamboo roofing system is that it requires regular maintenance and replacement every five years. However, you can enhance its lifespan by having three layers as follows:

• First layer: Woven bamboo mats that also serve to enhance indoor aesthetics.
• Second layer: Asphalt liner sheets for protection from water and heat.
• Third layer: Bamboo splits arranged in an overlapping pattern.

This triple-layer system provides excellent insulation, protection from the elements, and noise and thermal regulation throughout the year. Moreover, they give a home a unique aesthetic touch that is hard to resist.

Terracotta Tile Roofing

Terracotta roofing is a popular option in many countries. It involves using clay tiles to form a protective layer for the roof. Such roofs can last more than 100 years.

Bamboo splits are combined with terracotta tiles to protect the roof and increase its lifespan.

The splits are used as fixtures that hold the tiles together, allowing them to form a sturdy and long-lasting roof.

This bamboo roofing also comes with excellent insulation properties that can help keep temperatures inside the house cool even in hot summers.

A point worth noting is that this roofing system works well for linear buildings. They also need battens or laths to hold the tiles in place.

The recommended roof pitch is at least 35 degrees, with rafters no more than 30 cm (11.81 inches) apart.

Flattened Bamboo Roof

Flattened bamboo roofs are made by splitting bamboo poles half lengthwise to convert them into roofing shingles.

A cut is then made on the interior part of the culm wall with a hatchet. This cut must not pierce through the entire culm wall – just slightly weaken it to permit the flattening of the culm.

The flattened bamboo is then set over the rafters in an overlapping pattern. This technique allows for a sturdier and more durable roofing system.

The aesthetics of this type of roofing are stunning, and it’s ideal for tropical countries as its insulation properties can help reduce energy bills.

For best performance, the roof should have at least a 40-degree pitch angle and rafters no more than 40 cm (15.75 inches) apart.

This bamboo roofing system works well for curvilinear roofs.

Copper Roofing

This is a recent technique of roofing that combines bamboo with copper sheets customized into tile shingles.

The copper sheet is cut into individual tiles, then threaded onto the split bamboo rafters. This technique helps increase its stability and longevity.

Copper roofing works best for curvilinear roofs.

Installation involves laying wooden bamboo mats over the rafters, attaching an asphalt liner using a nail gun, and cladding customized hand-cut copper tile shingles over the liner.

For best performance, copper roofing must have at least a 15-degree pitch and rafters no more than 60 cm (23.62 inches) apart.

The main advantage of bamboo copper roofing is that it’s durable and beautiful–it doesn’t require regular maintenance as with the other types.

These are some of the bamboo roofing techniques available. Each type has advantages and drawbacks, making it ideal for different uses. However, with proper maintenance and installation, these roofs can last a long time.

Is a Bamboo Roof Waterproof?

A bamboo roof is waterproof because bamboo has a natural silica layer that repels water and protects it from the elements. This layer also helps keep the roof free of mold and rot, which can be potentially dangerous for a building’s structure.

Moreover, bamboo roofs have excellent ventilation properties that help prevent moisture buildup inside the house.

Bamboo roofing can be effective and long-lasting when properly installed with the right materials and techniques.

Although bamboo has these properties that make it waterproof, it’s worth noting that it’s a natural material. Like other natural materials, bamboo is apt to deteriorate over time, a factor that makes it susceptible to water damage. Therefore, it’s your responsibility to protect the roof from deterioration by maintaining and waterproofing it.

Waterproofing your bamboo roof makes it last longer as it offers protection from moisture, as well as UV rays, and other elements that may cause damage over time.

The common ways to waterproof your bamboo roof include:

Pitching the Roof

A roof pitch refers to the angle with which the roof slopes from the highest to the lowest point close to the walls.

Roofs in tropical climates with high rainfall must be pitched at an angle of more than 20 degrees based on the following factors:

• The type of roofing materials.
• Building and roofing codes in the country.
• Weather (areas with heavy rainfall need steeper pitch angles).

A rule of thumb is to build bamboo trusses at a calculated angle before bolting them to the load-bearing wall.

Pitching your roof creates a slope that helps direct water flow toward the outer walls and away from the bamboo trusses.

Layering the Bamboo

This involves coating the bamboo trusses with layers of rubber tree oil (2 to 3 layers are sufficient).

It’s recommended to thin the oil before use because it’s highly viscous.

You should only layer the trusses after bolting them onto the load-bearing walls. Here is the procedure:

1. Install an under-structure made of a woven bamboo net.
2. Install the first layer of interlocking bamboo shingles or split culms.
3. Install a second layer that makes up structural bamboo. This is the layer onto which the exterior roof will be attached.
4. Install a layer of split bamboo onto the exterior roof.
5. Add a layer of thick linen sheets soaked in tar.
6. Lay an outer layer of split bamboo. You must protect this layer with rubber oil to keep moisture and rainwater at bay.

Adding Overhangs

Overhangs help divert rainwater off the roof onto the ground, eliminating contact with the bamboo trusses and walls. The overhang should be at least one foot wide (0.3 meters), extending over the roof’s edge.

This helps protect the trusses and walls from rain, keeping them dry and prolonging their lifespan.

It’s also essential to ensure that your bamboo roof is fixed securely to avoid any movement during strong winds, as this could cause damage to the structure.

How Long Does a Bamboo Roof Last?

A bamboo roof can last between 6 months and more than 30 years, depending on its state of treatment and protection from the elements. Untreated bamboo roofs have the shortest lifetime due to exposure to moisture and sun.

Bamboo roofs treated with chemicals and waterproofed regularly can last decades.

Ultimately, the longevity of a bamboo roof depends on how it’s maintained and cared for, which is why regular inspections are necessary.

The inspections include checking for any signs of damage or decay that could affect the structure’s integrity.

Regular waterproofing also helps ensure your bamboo roof lasts longer.

How Do You Put up a Bamboo Roof?

Putting up a bamboo roof can be daunting if you don’t have the right tools and knowledge.

Therefore, it’s crucial to understand the process before embarking on it, which helps the process go smoothly and ensures you do it correctly, avoiding problems down the road.

We’ll get to the process of putting up a bamboo roof, but before we get into that, here’s a list of the equipment you’ll need.

• Bamboo poles.
• Measuring tape.
• Staple gun.
• A saw.
• Thatch.
• Lashing code.
• Framing screws.

Procedure for Installing a Thatched Bamboo Roof

1. Planning and designing your roof: Measure the structure you want to install the roof on to determine how much bamboo and thatch to order. You should also decide the type of roof; curvilinear, circular, or linear.
2. Build the roof frame with bamboo poles: Connect the bamboo poles with lashing cords or screws to form the frame. An A-frame roof is suitable for a rectangular roof. Remember to coat the poles with rubber tree oil or any other waterproofing agent.
3. Connect and attach the thatch: Lay the thatch on top of the roof frame, starting at one end and working your way to the other. Secure it in place using a staple gun.
4. Finish up: Cut excess thatch and secure the edges with lashes or screws.

Can Bamboo Be Used in Pergolas?

Bamboo can be used in pergolas in two ways; for roofing or attaching on the sides to create a cozy sitting area. It provides shade and insulation while allowing the breeze to pass through.

A key benefit of using bamboo when building pergolas is its variety of landscaping possibilities. It can be used creatively to create a unique outdoor space and provide a natural ambiance.

Moreover, bamboo is flexible enough to make different shapes while retaining strength. This makes it an ideal material for constructing arbors or pergolas in any environment.

How Bamboo Roofing Compares to Other Types of Roofing

Compared to the other types of roofing like asphalt shingles, clay tiles, metal roofing, or thatch, bamboo roofing has the following pros and cons:

Pros

• Sustainability: Bamboo is a sustainable and eco-friendly material. It grows fast and doesn’t require replanting after harvesting. This is one of the reasons people like using bamboo roofing.
• Lightweight: Unlike other types of roofing, bamboos are lighter, making it easier to transport and install.
• Insulation: Bamboo roofing provides excellent insulation that keeps a home cooler in the summer and warmer in the winter.
• Aesthetics: Bamboo roofing has a unique and attractive look that enhances a home’s natural beauty.

Cons

• Requires waterproofing: Bamboo is an organic material that needs waterproofing when used for roofing.
• It’s costly: Bamboo roofing can be more expensive than other types because waterproofing and treating bamboo adds to the overall cost.
• Limited availability: Bamboo may not be readily available in some regions.
• Fire risks: Although bamboo is a fire-resistant material, it’s not as good as sheet metal, so it can be a concern in areas prone to wildfires. 

Final Thoughts

Bamboo roofs are aesthetically pleasing and offer a range of benefits that make them a popular choice for homeowners and architects.

Bamboo roofs have become a sustainable alternative to traditional roofing materials thanks to their eco-friendliness and versatility.

Whether you’re building a new home or planning to renovate an existing roof, consider bamboo as a viable option.

Now that you know more about bamboo roofs, check out these awesome examples of bamboo architecture.