Bamboo is a versatile and sustainable material that is growing in popularity for outdoor applications like fencing, pergolas, and decking. However, untreated bamboo will quickly deteriorate when exposed to the elements. Properly treating bamboo is essential for protecting it from rot, insects, UV damage, and mold when using it outdoors. With the right treatment and care, bamboo can last for many years in an outdoor setting. Here is a comprehensive guide on how to effectively treat bamboo for long-lasting outdoor use.
Choosing the Right Bamboo Species
When selecting bamboo for outdoor projects, it’s important to choose a species that is naturally resistant to rot and insects. The best options include:
Tre Gai Bamboo
Tre Gai bamboo is one of the most rot and insect resistant species. It has a high silica content in its culms (stems) which helps protect it from degradation. Tre Gai is a good choice for outdoor furniture or pergolas.
Mayan Bamboo
Like Tre Gai, Mayan bamboo has naturally high resistance to rot and insects. It has thick culm walls and dense fibers that protect against weathering. Mayan bamboo is suitable for fencing, screens, and decking.
Guadua Bamboo
This bamboo species is well-known for its durability and strength. Guadua is regularly used for housing construction in South America. When properly treated, it can be used for poles, framing, and outdoor structures.
Yellow Groove Bamboo
Yellow Groove has good natural durability and insect resistance. It has frequently been used for window frames and flooring. With treatment, it can also be suitable for outdoor pergolas and fencing.
Choosing the right bamboo species is the first step for success. Avoid using non-durable indoor species like Moso outdoors.
How to Treat Bamboo for Outdoor Use
Proper treatment is crucial for protecting bamboo from degradation when used outside. Here are the key steps:
1. Cut and Cure the Bamboo
Once harvested, fresh cut bamboo needs to be air dried or “cured” to reduce its moisture content. This helps prevent cracking and improves absorption of treatment chemicals. Lay bamboo horizontally with good airflow for 2-4 weeks until moisture content is below 15%.
2. Inspect for Damage
Inspect each piece and cut away any cracked or split sections which can allow moisture inside. This step helps identify weak points for maximum treatment penetration.
3. Choose a Treatment Method
There are several effective options for treating bamboo:
- Borate solution: Borates are wood-penetrating minerals that protect against rot, fungi, and insects. Soaking bamboo in borate solutions like Tim-Bor provides excellent protection.
- Oils: Tung oil, linseed oil or exterior penetrating oils waterproof and preserve bamboo. Multiple applications are needed for full protection.
- Varnishes and resins: Marine grade varnishes or resins seal and weatherproof bamboo surfaces. Multi-coat applications are required.
- Heat treatment: Exposure to heat of 160-210°C changes bamboo’s cell structure increasing durability and weather resistance.
- Pressure treatment: Forced impregnation of chemicals like copper azole under high pressure maximizes penetration into bamboo. Requires professional equipment.
Workplace safety is important when handling treatment chemicals. Always use proper PPE and ventilation.
4. Apply Protective Coating
Treated bamboo will still gradually weather and gray without a protective finish. Use water-resistant stains, paints or clear coats to protect your bamboo from UV damage. Reapply clear coats annually.
5. Allow Proper Drying Time
Always let treated bamboo dry thoroughly before installation. This helps the chemicals penetrate fully and avoids trapping moisture. Drying times vary based on treatment method.
6. Handle with Care
When transporting and installing treated bamboo, take care to avoid cracks, scratches or splits which can allow moisture inside. Use plastic wrap to protect during construction.
Proper treatment will protect your bamboo for decades of outdoor use. Always use safety gear when handling chemicals and allow adequate drying time.
Frequently Asked Questions About Treating Bamboo for Outdoor Use
Treating bamboo for outdoor use can seem complicated for those unfamiliar with the process. Here are answers to some frequently asked questions:
Does All Bamboo Need Treatment for Outdoors?
Not necessarily. Some naturally durable species like Tre Gai have higher rot and insect resistance untreated. But even these will weather and fade faster without treatment. Proper treatment ensures maximum longevity outdoors.
How Long Does Treatment Last?
With proper application, bamboo treatment chemicals can protect for 5-15 years or longer before reapplication is needed. Duration depends on treatment method, exposure, and climate. Recoat bamboo annually with waterproof finishes.
Can I Use Left-Over Indoor Bamboo Outside?
Bamboo intended for indoor use will quickly fail outdoors if not treated. Non-durable varieties like Moso have no rot resistance. They should only be used outside if properly treated first. Always choose naturally durable species.
Is Heat Treated Bamboo Good for Outdoors?
Heat treatment improves bamboo’s durability and weather resistance. But it does not protect against rot, fungi or insects. An additional treatment like borate is recommended for full outdoor protection.
Does Bamboo Treatment Have an Odor?
Some treatments like borates, tung oil or resins have light odors during application. They dissipate as the bamboo dries. Proper ventilation is recommended. Treated bamboo itself has no lasting odor.
Is Treated Bamboo Safe Around Pets and Kids?
Once bamboo treatment chemicals have fully dried, they pose no toxicity risks for humans or animals. Always allow proper drying time before installation in pet areas or children’s play structures.
How Soon Can Treated Bamboo Get Wet?
Avoid exposing treated bamboo to moisture until it is fully dry. This allows maximum chemical penetration and efficacy. Drying takes 24 hours to 2 weeks depending on treatment. Carefully cover untreated bamboo when not in use.
With the right preparation, treatment and care, bamboo can be just as durable as wood for outdoor projects. Always use naturally weather-resistant species and proper chemical treatments for long-lasting performance outside.
Outdoor Uses for Treated Bamboo
Properly treated bamboo is an eco-friendly and eye-catching addition to any outdoor space. Here are some popular applications:
Bamboo Fencing
Bamboo fence slats or panels create a living fence with an exotic look. Naturally insect resistant species like Mayan Bamboo work well. Use post anchors and allow airflow between slats to prevent moisture buildup.
Bamboo Pergolas
A bamboo pergola adds style and shade. Look for durable species like Guadua or Tre Gai bamboo for the vertical posts. Use slats or latticework for optimal airflow to prevent rot. Waterproof finishes will extend life.
Bamboo Decking
With proper treatment, bamboo makes a beautiful and sustainable decking alternative to tropical woods. Opt for solid boards instead of laminates. Allow drainage between boards and use waterproof coatings.
Bamboo Poles for Structures
Treated bamboo poles are ideal for screens, awnings, or small structures like tiki huts. Choose a naturally rot-resistant species and apply borate or copper azole treatment for longevity.
Bamboo Outdoor Furniture
Lightweight yet strong, bamboo is perfect for chairs, loungers, or tables. Use steam-bent bamboo for curved shapes. Tre Gai and Mayan species are suitable choices for durable outdoor furniture.
Bamboo Gazebos
A bamboo gazebo with a shingled roof creates an ornamental garden retreat. Use thick-walled Guadua or a similar durable species for the framing. Allow for drainage and airflow to prevent moisture trapping.
With proper care, treated bamboo can enhance outdoor living spaces for years of enjoyment. Always inspect annually for wear and reapply weatherproof finishes as needed.
Best Practices for Working With and Installing Treated Bamboo Outdoors
Follow these tips to safely work with treated bamboo and get the longest service life after outdoor installation:
- Wear gloves, eye protection, and dust masks when sawing or sanding treated bamboo to avoid inhaling dust particles. Work in well-ventilated areas.
- Pre-drill holes for screws or hardware. Avoid splitting bamboo which allows moisture inside. Use stainless steel or coated fasteners.
- Allow 1/8″ spacing between bamboo decking or siding boards to enable drainage and airflow. Prevent moisture from being trapped between boards.
- Keep bamboo off ground contact with post anchors or supports. Allow air circulation underneath to prevent moisture wicking up into the material.
- Apply end caps or seal cuts and ends with waterproof finishes. Unprotected bamboo ends will wick up moisture like straws.
- Inspect bamboo annually for wear and cracks. Sand and reapply waterproof UV-resistant finishes to maintain weather resistance.
- Clean bamboo outdoors with mild soap and water. Avoid harsh chemicals which may interact with treatment chemicals.
- Dispose of bamboo dust and construction debris properly. Borates and other chemicals can be harmful to plants, soil and waterways if not handled properly.
Proper installation and care will help your treated bamboo projects endure years of service in outdoor environments. Always use safe handling procedures when working with treated bamboo.
Conclusion
With the right preparation and treatment, bamboo can be a beautiful, eco-friendly, and long-lasting material for outdoor uses ranging from fencing to furniture. Start with naturally durable species, allow proper curing and drying, and use borate solutions, oils, or other treatments for comprehensive protection from the elements. Handle freshly treated bamboo carefully to avoid compromising its defenses. With annual upkeep and the best installation practices, your bamboo projects can withstand decades outdoors while enhancing your living space. Treated correctly, bamboo is a sustainable and versatile choice that allows endless design possibilities for your outdoor oasis.