Replies

1. 
   ERIC WHETZEL | May 10, 2022 02:11pm | #1

   In my experience, the stain isn't likely to help much, especially now that they've found your exposed framing. We had the same issue on our house --- long delay between framing and siding going up.

   The only thing that I found to really work is to directly spray the females that are making the holes if you can. Once you're reasonably sure there are no bees returning to that particular hole, I spray food grade diatomaceous earth with a 'puffer' applicator directly into the hole.

   https://www.diatomaceousearth.com/

   https://pfharris.com/products/harris-diatomaceous-earth-crawling-insect-killer-4-lb

   I then wait a day or two to make sure no bees are entering/leaving the hole before filling it with steel wool. At that point you can just caulk over the steel wool.

   The challenge with carpenter bees is once they find a site they like they'll return year after year unless you interrupt their life cycle. Even when you think you have them all, you'll need to be diligent and look out for them and address them should any others show up.

   Our first year we had about 12 holes, second year about 4. Two summers ago we had none. Last year only one. Spring and fall are when you really need to be on the look-out for them.

   I don't enjoy killing helpful pollinators, but, if you address the issue early, there shouldn't be too many to get rid of.

   This video does a pretty good job explaining the issue:

   https://youtu.be/GN8ItzitvG8

1. 
   derekr | May 10, 2022 02:41pm | #2

   Ok thanks, the staining won’t hurt the strength of the wood overtime or anything since I sprayed the trusses where they are resting on the opening though right? I would hate for the roof to collapse on me in 10-15 years lol

   This is my first house and I’m just being over cautious

   I won’t be worried about the bees once everything is closed in, it’s just the house is wide open right now

   The stain I bought is called eco wood treatment and the company says it will stop carpenter bees but not termites, I just put spray foam into the holes after I got rid of the bees

2. GBA Editor
   Kiley Jacques | May 10, 2022 03:39pm | #3

   Eric,

   I spent a few years working in an entomology lab on various IPM projects using biological control agents, so I really appreciate your advice here. So few people understand that it is an insect's life cycle that needs to be interrupted to get control and prevent/stop damage. That targeted, well-researched approach is key but most people just go after pests in a broad-spectrum kind of way--spraying anything on everything at any time of year. Those types of efforts generally lead to more problems.

2. Expert Member
   BILL WICHERS | May 10, 2022 06:24pm | #4

   Kiley, I like that you mention the "broad spectrum" spraying as an issue. I live in an area with tick problems, and I've been out to find something that will target the ticks, but not everything else. Permethrin is great for ticks, but it will get most other insects (butterflies, etc.), and can mess with water ecosystems too, and since I have marshes, streams, and a small lake, I try not to mess those up. Right now I use 'tick tubes', which are permethrin-treated cotton stuffed into cardboard tubes that rodents use for nesting, and that helps mess up the tick's life cycle since they tend to travel around on mice and the like. This is less impactful to the rest of the area. I find my lawnmower is helpful too :-) So many insecticides get all kinds of "good" critters that you really need to be careful and only very selectively apply them if you use them at all.

   For the OP: Staining wood shouldn't really affect it structurally unless you managed to super saturate the wood enough that it got spongy. I don't see that as a realistic possibility though, so you should be fine. I have myself used coppercoat to treat exposed non-pressure treated lumber that I am concerned might have insect problems one day. I painted my rim joist (which is untreated lumber) with copper coat prior to insulating it with EPS, for example, as a bit of extra insurance from insect damage after the insulation made it difficult to see if anything was amiss.

   Note that many/most insects can and will tunnel right through canned foam, so I'd recommend putting some aluminum window screen in before injecting foam. The screen will make an insect barrier within the foam (the foam will encapsulate it), which will stop insects from tunneling through. Steel wool can help too, but the foam is unlikely to penetrate that, so there is nothing to lock it in place. Remember that insects can usually chew up soft things, so it takes metal things to really put a stop to them.

   Bill

1. 
   derekr | May 10, 2022 10:46pm | #5

   Thanks, the wood stain I used is non toxic and doesn’t harm anything in the environment

   The company and some customers have said it will stop carpenter bees from digging in the wood so I’m ready to see if the results are true

1. Expert Member
   BILL WICHERS | May 11, 2022 12:34am | #6

   If it's non toxic and doesn't harm anything, how is it supposed to deter the bees? Typically there are three ways to stop pests: physically prevent them from getting in (screen, etc.), deter them (pheromone or similar stuff that they don't like so they leave), or some kind of stuff that hurts and kills them (poisons, diatomaceous earth, etc.).

   I'd be suspicious of other products that claim results but aren't one of those three things. The first two tend to be the least likely to harm anything besides your targeted pests. The problems with poisons is that most aren't very selective, so they can harm other things that you didn't intend to hurt.

   Bill

1. 
   derekr | May 11, 2022 06:30am | #7

   Not sure how it works but it changes the wood and never needs to be reapplied it has good reviews

   https://www.amazon.com/Eco-Wood-Treatment-EWT1-Semi-Transparent/dp/B00KX05BE2

   https://ecowoodtreatment.com/

   I also had a pest company come spray my subfloor in the crawl space to stop termites and they also said it wasn’t poisonous it was borate or something like that, this eco wood treatment doesn’t stop termites though but they said it will stop some insects such as carpenter ants and carpenter bees

1. Expert Member
   BILL WICHERS | May 11, 2022 08:24am | #8

   Borates kill the fauna that allow the temites to digest the wood. Borates are a selective way to kill off termites that has only limited toxicity to other things, which is a Good Thing here.

   Bill

2. 
   derekr | May 11, 2022 10:57am | #9

   Do you know how cypress fairs against carpenter bees? I’ve already bought 500 feet of it to put up as trim around my house