Wasps nesting under slanted wood trim on gable side of building

[JayN]

I live in a condo (end unit townhouse). There is a slanted wood trim near the roof on the side of the building. There is a gap behind the wood trim and wasps (yellowjackets) have been flying into the gap behind the wood trim and building nests there. Although I wasn't aware of this at first, my impression is that they have been nesting there every year. I've been here almost 4 years.

If they haven't gotten inside the building or bothered anyone, are they best left alone, or does leaving them alone typically lead to them causing damage?

Seems to me the only permanent solution would involve screening off the gap, but the wasps would need to be exterminated first, and one would have to be very certain they are all dead before screening off the gap. Should I insist this be done, or are they best simply left alone?

Thanks,

Jay

[aemeijers]

You block off the gap after the 2nd or 3rd hard frost, if you get frosts in your area, and don't want to pay for an exterminator. Wasps (the kind that build mud nests) are a PITA to grounds crew, kids, pets, etc, but seldom do actual damage. Other flying things, like bees, or the flying things that bore holes to nest in, can get in the wall and trash the place. I would definitely bring this to the attention of the association or the management company. Likely they have an exterminator on retainer. Is this an actual gap between trim boards, or are they just hanging a nest behind the shadow line of the fly rafter, out of the rain? Take a walk and look at the other roof ends in the complex. Do they all have the gap you are referring to, or did the finish carpenter just make a boo-boo on your building? If you have a camera that can zoom in, pictures are always useful to turn in with the report, otherwise you may have to actually show somebody in person.

aem sends...

[Phisherman]

You could just leave them alone. Personally, I would use wasp/hornet spray (just after sundown) and be done with it.

[Frank]

Paper wasps, I leave alone, but yellow jackets, I kill. Nasty little buggers and you never know when one will sting you. One sent me to doctor with swollen hand from single sting on a finger.

Sealing the opening before or after you spray the nest will get rid of them as the trapped ones will die off. I've had a lot of problems with yellow jackets nesting in house through smallest crevices and have had to seal off outside house lights as they were getting under the fixture and getting in the wall through the conduit opening. One on front porch, I sealed openings and could hear buzzing in wall which eventually stopped.

For spray, get one of those wasp and hornet sprays that reach 25 feet. If you get in nest opening you will kill nest. When they nest in lawn, I'll dump a gallon of pesticide solution in opening.

[The Ranger]

You don't mention if you have access to a ladder. If you don't have access to a ladder, how were you planning on getting up on the roof to take care of this problem? I'd call the property management and have them get Terminex (or whoever they've contracted with) out there. If you do [have a ladder], and will not be going against any of your HOA regulations by climbing up on the roof or whatnot, then purchasing one of the power-spray insecticides specific to wasps would be one solution. You can fire at the opening from a safe distance (usually

20-25 feet) and not worry about getting stung.

The Ranger

[franz fripplfrappl]

Wait until the come home to roost. Then dowse the crack with a goodly portion of hornet/wasp spray AFTER sunset. That'll kill what's in the nest and discourage others. You may have to repeat every season. I've had good luck with this approach.

when you are convinced they're gone, caulk.

[JayN]

The slanted piece of wood I'm talking about is outside the building on the gable end. It is parallel to the rafters of the roof, but the siding was slid underneath it. Is that the fly rafter, or just a piece of wood trim? The roof does extend outover that piece of wood. Not sure if that wood is holding anything up though, since it is further out than the siding. Is a fly rafter something that holds the roof up, or is it just a piece of slanted wood trim?

It looks like when they installed the siding, the siding was slid underneath that piece of wood. The gap I am referring to is between that piece of wood and the siding. You can see the gap when looking upward from the side of the building. The bees are putting up paper nests there which are protected from the rain. It is very hard to see the nest, because the slanted piece of wood conceals them. You really have to be looking carefully up into the gap to see the nests.

Is it okay to leave them be, or should I insist the bees be exterminated, and the gap sealed off afterward?

Thanks,

J.