Purple martins are migratory swallows that nest in cavities, and they readily accept man-made birdhouses. Providing an appropriate house can encourage these beneficial insect-eating birds to take up residence in your yard. When building or buying a purple martin house, the type of wood used is an important consideration. The wood needs to be weather-resistant, safe for the birds, and attractive. This article will discuss the pros and cons of various wood types to help you make an informed decision when selecting or building a purple martin house.
Cedar Wood
Cedar is one of the best woods for constructing a purple martin house. Here are some of the benefits of using cedar:
- It has natural resistance to rot, mildew, and insects due to its high levels of natural oils.
- Cedar has good insulation properties, helping regulate temperatures inside the birdhouse.
- It is a lightweight wood that is easy to work with and cut to size.
- Cedar has an attractive reddish hue that blends into natural environments.
- It is affordable and readily available at most hardware stores.
Cedar is one of the most popular and recommended choices for purple martin housing. Untreated cedar rates very high for durability and can last over 10 years with proper maintenance. The wood is safe for the birds and will not degrade or leach chemicals into the environment. The natural oils in cedar also help deter parasites.
Pine Wood
Pine is another viable option for purple martin houses. Considerations when using pine include:
- Pine is an inexpensive, lightweight softwood that is easy to work with.
- It is widely available, making it accessible for DIY birdhouse projects.
- Pine has a rustic, natural look when left unfinished.
- It lacks natural rot resistance, so pine needs to be treated or painted.
- Pine is not as durable as cedar, lasting 3-5 years on average.
- It is critical to use non-toxic finishes on pine to keep it safe.
Pine can make a good choice if it is properly treated and maintained. Opt for a naturally rot-resistant species like pressure-treated pine. Unfinished pine will need to be replaced more frequently than cedar. With non-toxic paint or stain, pine martin houses can have aesthetic appeal.
Cypress Wood
Here are some key factors regarding cypress wood for purple martin houses:
- Cypress is naturally resistant to insects, decay, and rotting due to its high cypressene oil content.
- It is a dense, strong wood that withstands weathering well.
- Cypress has an attractive grain pattern and color.
- It is more expensive than pine or cedar.
- Availability may be limited depending on geographic location.
- Unfinished cypress will turn a silver-gray color when exposed to the elements.
The natural durability and longevity of cypress make it an excellent choice. With proper yearly maintenance, cypress houses can last over a decade. The expense may be justified by not having to replace the house as often. If desired, cypress can be painted or stained to maintain a more uniform appearance over time.
Avoid These Wood Types
Certain woods are poor choices and should be avoided when building purple martin houses:
- Plywood – Made from layers of thin wood bonded together, plywood is not durable enough for long-term outdoor use and will de-laminate when exposed to weather.
- Chipboard – This composite wood product lacks strength and can swell and degrade rapidly in outdoor conditions.
- Fiberboard – Like chipboard, fiberboard materials swell and delaminate when subjected to moisture and humidity.
- Green lumber – Freshly milled “green” wood will crack, warp, and twist as it dries out.
- Treated lumber – Wood treated with chemical preservatives like creosote or pentachlorophenol are toxic.
Avoid any wood products that contain glues, chemical treatments, or that lack weather-resistance. Use only natural, untreated woods that are known for durability.
Choosing the Right Wood Thickness
Most purple martin house plans recommend using 3/4 inch thick lumber for the best results. Here are some guidelines on wood thickness:
- 3/4 inch wood provides the ideal balance of durability, insulation, and weight.
- 1/2 inch wood is cheaper and lighter but more prone to warping and breaking.
- 1 inch wood is heavier and more expensive but very durable.
- 2 inch is too heavy and unnecessary unless making a mega-house.
For a happy medium, go with 3/4 inch lumber for the sides, floors, dividers, entrance holes, and roofing. Slightly thinner 1/2 inch wood is acceptable for decorative elements like porches. Heavier 1 inch wood can be used for the mounting post or pole if desired. Just ensure the house does not become too heavy overall.
Best Practices for Durability
Follow these tips to help maximize the lifespan of your wooden purple martin house:
- Use metal fasteners and hardware rather than wood glue or nails.
- Apply a UV-protectant finish annually.
- Inspect for damage and decay each year after migration season.
- Make any necessary repairs after inspection while the house is empty.
- Install predator guards around entrance holes.
- Have a roof overhang for protection from rain.
- Seal any cracks with a flexible caulk.
Taking steps to properly care for and maintain your martin house will keep it in good condition year after year. Investing in quality materials and construction from the start will also improve longevity.
Appearance Considerations
Beyond durability, wood choice also impacts the look of the finished purple martin house:
- Cedar has a reddish-brown hue that blends into nature.
- Unfinished pine develops a silvery-gray patina as it weathers.
- Cypress ranges from yellow to brown in color.
- Wood can be painted or stained for custom colors.
Natural wood tones are attractive for a rustic look. For a bright pop of color, paint the house white or go bold with a vibrant purple. Just be sure to use only non-toxic paint approved for birdhouses. Consider the style of your yard when choosing colors and wood type.
Conclusion
When it comes to the best wood for purple martin houses, cedar is the top choice for its durability, weather-resistance, insulation, and safety. Pine and cypress are also good options when properly treated and maintained. Use untreated, non-toxic woods that are 3/4 inch thick whenever possible. Follow sound construction principles and annually maintain the house. Choosing the appropriate wood will help your purple martin house last for many seasons while attracting these special birds to your property.