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Community and Q&A

Concerned about carpenter bees and wood trim I already bought for my house

derekr | Posted in General Questions on

I really liked the look of Cypress so I bought it as trim for my whole house before I found out carpenter bees were going to be a problem

from my understanding what I read online the bees only like to dig in wood that’s 1 to 2 inches thick or more while my cypress trim I bought is only .75 inches thick, could this deter them from it? Will the cypress itself deter them?

if they do dig through the cypress and get through it will they continue to dig into my house framing that’s behind the cypress or do they tend to stay in the same wood they started in? Like would they get in my roof trusses behind the cypress?

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  1. tim_dilletante | | #1

    My experience with carpenter bees is that they tunnel in a few inches then stop. They aren't building ant farms. I am sure a wiser member will chime in.

    1. derekr | | #2

      They can go up to 10 feet if they revisit the same holes over the years

      And if you have like 15 or 20 bees doing that over many years that sounds like structural damage to me

      1. Deleted | | #3


  2. ERIC WHETZEL | | #4

    All of the carpenter bee holes (nesting sites) we've had on our house were made in 1x6 and 1x8 (3/4" thick) fascia and trim boards, so I don't think the thickness of your boards will deter them. I doubt because it's cypress that it will matter much either.

    If you can't, or don't want to, monitor their presence and address them if/when the bees do show up, you may be better off going with a more durable material like fiber cement.

    1. derekr | | #5

      When they got in your fascia board did they go beyond it and into your framing?

      Already paid thousands for these not changing now, guess I’m just going to hope the cypress and my stains deter them

      I may put aluminum strip behind the trim to make me feel better

  3. ERIC WHETZEL | | #6

    It looked like they entered and then turned almost immediately to create their tunnels, staying in just the 1x material. Sometimes they entered through the face of the board, but most of the time they tried to go through the bottom edge.

    Even on my black siding, the holes are pretty easy to spot.

    Usually we saw individual bees hovering around a certain spot over and over before we saw a hole. In some cases I was able to spray a bee before a hole was even completed, which definitely makes things easier.

    As long as you don't mind periodically checking for holes and addressing them, it should be fine to use the cypress.

    1. derekr | | #7

      What kind of wood is your fascia?

      1. ERIC WHETZEL | | #8

        It's cedar with a 'charred' or shou sugi ban finish.

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