Bat(t)s in the attic

[Sophon]

I have a couple of problems/projects coming up, so I thought I would ask for input from the collective fountain of knowledge of the forum.

 

Firstly, we have a colony of bats living in the attic above our main bedroom, they have taken up residency between the roof tiles and the reflective foil. In principle I don't mind cohabiting with them, as they aren't much of a nuisance, other than being a little noisy chirping away when they come home from their hunting trips around 3 or 4 in the morning. Occasionally, one gets pushed out of the nest, and makes quite a racket flying around in the attic banging into the hanging wires for our suspended ceiling or scuttling around on the gypsum looking for it's way back. But that is just temporary, eventually they tend to find their way back into the nest and all is quiet again.

 

However, there is one big problem with having a bat colony in your attic - bat guano. Their droppings/pee are piling up in two corners of the bedroom (one in particular), and it has come to a point where it's seeping through the gypsum at the corner down the wall into the bedroom below. If doing nothing, It will eventually start to affect the integrity of the gypsum ceiling. I have covered the corners with plastic to catch the droppings and keep them away from the ceiling, but that means that I will have to go up there from time to time to clean away the guano. And the problem is, of course, in the far corners of the attic with no good way to get there, other than using the roof structure metal as monkey bars to keep my weight away from the ceiling (I don't trust the suspended ceiling to be able to carry my full weight). I am getting too old and out of shape for that, and definitely will be in a few years.

 

So the permanent solution would seem to get rid of the bats, but how? Are there solutions other than going all around the roof plugging up every little gap where they can get in with expanding foam or similar? That would be a major undertaking, and would probably require scaffolding all around the house (I think it would be too dangerous a job to do from a ladder). I would, of course, have to leave a few gaps where the bats could get out but not in again (one way traps, or manually block them every night after the they leave). Does anyone have an alternative and less labour intensive solution?

 

Secondly, I am about to install insulation batts on top of the suspended ceiling. I am hoping that it will keep the rooms a little cooler in the hot months, and maybe even a little warmer in the winter months. I already did the main bedroom (since I was up there anyway for the bats), and it does seem to have an effect. The underside of the gypsum in the bedroom is now 3-5 degrees colder than in the other rooms of the house. As a bonus the noise from the bats are also a little more muted now.

 

Now to my next question; I am about to do the living room, which unlike the bedroom has the standard recessed down-lights. Obviously, I will have to make cut-outs in the insulation batts for the lights, but do I have to leave a safety margin? I assume that the batts are made from a fireproof material, but I have a vague recollection that you still had to cut out extra margin for heat dissipation. Is that still the case now that we are not using incandescent bulbs anymore, but instead 7w led or 11w cfl bulbs? More than half of the light will be protruding even after the insulation batts have been installed, which I would expect to be enough? Or am I wrong about the insulation material, and failing to leave a safety margin will create a fire hazard?

 

Thanks in advance for your input.

Edited January 24, 2020 by Sophon

[spinner2020]

Smoke them out? Obviously it will make a one-off mess of the house, but should work.

 

Or ultrasonic, of which I have previously heard (no pun) mixed reports in Europe where we once had a problem. Try this one which looks like it ships to LoS:

https://www.amazon.com/gp/product/B01E6DHFPE/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B01E6DHFPE&linkCode=as2&tag=bat-guide-20&linkId=8f240a93b3a42d1cd6bea455778c83ff

[Sophon]

29 minutes ago, spinner2020 said:

Smoke them out? Obviously it will make a one-off mess of the house, but should work.

 

Or ultrasonic, of which I have previously heard (no pun) mixed reports in Europe where we once had a problem. Try this one which looks like it ships to LoS:

https://www.amazon.com/gp/product/B01E6DHFPE/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B01E6DHFPE&linkCode=as2&tag=bat-guide-20&linkId=8f240a93b3a42d1cd6bea455778c83ff

I have thought about smoking them out, but while it will probably make them leave, I am fairly confident that they will come back again to check out the situation. And keeping the attic filled with smoke for days on end to make them stay away isn't really a viable solution.

 

I don't believe in the ultrasonic repellent devices (especially their claim that they will work against insects), and most reports/reviews point to them having little to no effect. However, since I could see how they could theoretically work on an animal using ultrasonic echo location, I thought I would give it a go anyway and bought three different of the cheaper models on Aliexpress, one (reportedly) with variable frequencies. No reaction whatsoever from the bats, although a couple of my dogs did perk their ears when I turned them on. I am not really willing to spend any more on something I don't believe will work.

 

I have also tried putting floodlights in the attic for a month to make the bats uncomfortable but that didn't work either, maybe because they are hiding behind the foil insulation so the lights have little effect on them.

 

Thank you for your suggestions.