Insulating a barn but afraid of mice...

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mwhitnee

Minister of Fire
Jun 10, 2015
586
Central Mass, USA
I recently bought a home with a little barn. It had many mice in it. The second floor was cleaned very well and vacuumed everywhere and I even mopped the floor a little. There were mice on both floors. I just finished gutting the first floor.

I pretty much eradicated them last year, but when tearing down the old ceiling between the first and second floor which had older drywall (only on half the ceiling, ?) The insulation was unbelievably bad and there were some mice in it. Like raining mouse chit. I literally grabbed a few smaller mice and put them in a bucket to release them. It was probably the nastiest job I have ever done.

Anyway, there are no walls/ceilings left (never were any walls and no ceiling on 2nd). The roof was stripped last year and a new roof on, as it was raining water inside and providing water for the mice. There is no food in the barn. I have some mouse traps set up but there really aren't any comfortable places to hide anymore.

I want to insulate the first floor and put drywall and a propane heater up, but I'm afraid the mice are just going to get back into the ceiling which would drive me nuts.

Any way to pretreat the insulation? I know of the typical ways to mouse proof but of they want to find a way in they probably will....
 
They won't find a way in unless you provide it. Build it like a house. Seal everything. I insulated the crap out of my barn but still sealed it well and store no food. No mice. Heck, i learned about good chemicals and now I have no spiders or insects either.
 
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I've experienced much the same situation in our house. The mice made a mess of the FG batts above our basement drywall ceiling. Removing and cleaning it up was much as you describe, a shower of dirt, insect parts, mouse crap, and FG insulation. It may be helpful to keep in mind that mice use invisible urine trails to navigate. Unless these are removed new mice will use them to enter and find their way around.
I'm rebuilding our basement and one of the reasons I chose mineral wool batt insulation was because of its reported dislike by mice. So your choice of insulation is important.
 
A lack of food an water wont deter them as they are looking for a warm place. Sealing every little gap is important.
 
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I have a concrete foundation, all of it sits off the ground before it hits the siding but in many places not much. But there are other areas where it almost touches the ground. Can mice climb up a concrete wall? How would I mouse-proof the bottom edge of the siding? The walls are also open on the inside so maybe there is a way I can seal the bottom of the wall.

Besides that there is no way in besides the doors.
 
Mice can jump, climb well, and fit through incredibly small holes. They can also chew through just about anything softer than metal including wood, foam, plastic, etc.
 
Sort of looks like this all around. How would I start mouse-proofing the bottom edge of the siding?

20150608_172131.jpg
 
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Inspect where the foundation meets the siding very closely. They can find little gaps to squeeze in. Find a material they dont like to chew to seal those gaps. I believe dow great stuff has a version made for pests which, maybe its bitter or something. Steel wool works, people use it in winter to block entry into their campers. Never used the mineral wool insulation for pest blocking, but it sounds like a good idea
 
I've experienced much the same situation in our house. The mice made a mess of the FG batts above our basement drywall ceiling. Removing and cleaning it up was much as you describe, a shower of dirt, insect parts, mouse crap, and FG insulation. It may be helpful to keep in mind that mice use invisible urine trails to navigate. Unless these are removed new mice will use them to enter and find their way around.
I'm rebuilding our basement and one of the reasons I chose mineral wool batt insulation was because of its reported dislike by mice. So your choice of insulation is important.


I am using this to spray before I insulate. It is s disinfectant, virucide, and fungicide.

http://www.odoban.com/products/odoban-concentrates.php
 
Mice will get in anywhere. I have watched them climb up the walls outside my house and get through a tiny 1/4" gap between the soffit and brick. If you seal everything at ground level, they'll just keep climbing until they chew a way inside. Metal lathe used for ceramic tile works well. Mice won't chew through it but rats will. Lack of food will keep your population lower but they will find food outside and bring it in to your barn. Be thankful you don't have racoon families inside your barn - yet!
The best method is to try to fill all the cracks with heavy steel wool, mouse traps everywhere, and go to your local SPCA or CL and get some free cats to patrol your barn. Feed them just enough so they're OK but fat cats do not hunt very well. You can get heavy stainless steel wool from restaurant supply stores. They use it to scrub pots & pans.
 
Mice will get in anywhere. I have watched them climb up the walls outside my house and get through a tiny 1/4" gap between the soffit and brick. If you seal everything at ground level, they'll just keep climbing until they chew a way inside. Metal lathe used for ceramic tile works well. Mice won't chew through it but rats will. Lack of food will keep your population lower but they will find food outside and bring it in to your barn. Be thankful you don't have racoon families inside your barn - yet!
The best method is to try to fill all the cracks with heavy steel wool, mouse traps everywhere, and go to your local SPCA or CL and get some free cats to patrol your barn. Feed them just enough so they're OK but fat cats do not hunt very well. You can get heavy stainless steel wool from restaurant supply stores. They use it to scrub pots & pans.


Allergic to cats and yes please no raccoon! I once had to deal with one though and caught it in a have a heart trap.

I bought copper mesh as I can probably cut it to lengths and then roll it into a tube, stuffing it under the first piece of siding. I would think that steel wool would rust if I used it for that particular application.

Can a mouse climb up vinyl siding?
 
Bronze wool and stainless can be had at a good wood tool store.
 
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Mice will get in anywhere. I have watched them climb up the walls outside my house and get through a tiny 1/4" gap between the soffit and brick. If you seal everything at ground level, they'll just keep climbing until they chew a way inside. Metal lathe used for ceramic tile works well. Mice won't chew through it but rats will. Lack of food will keep your population lower but they will find food outside and bring it in to your barn. Be thankful you don't have racoon families inside your barn - yet!
The best method is to try to fill all the cracks with heavy steel wool, mouse traps everywhere, and go to your local SPCA or CL and get some free cats to patrol your barn. Feed them just enough so they're OK but fat cats do not hunt very well. You can get heavy stainless steel wool from restaurant supply stores. They use it to scrub pots & pans.

Sorry I didn't see the stainless steel part of that message! Looks like Ebay has that..
 
Allergic to cats and yes please no raccoon! I once had to deal with one though and caught it in a have a heart trap

Garage cat then - in door out door, no inside the regular house kind of cat - I have a indoor out door in my house cat that is part feral and would rather live outside, but I force her in at night (food dish is inside) I couldn't believe how good of a hunter she is, no more mice, moles, chipmunks, birds, snakes, rabbits, butter flies. moths, ect.. neighbors love her to because of the major decrease in rabbit / mouse population.
 
Silicone works well for small gaps. Copper mesh or steel wool can be used as a backer. Pay attention to the door. All that work is for nothing if they can use the door. There are foams with pepper mixed in that will keep rodents out. Mice will enter a quarter inch gap as said above. Start at a corner and work your way around.
 
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I have found it is practically impossible to keep mice out of our house. I don't know how, but they find their way in. I keep a trap line going in the basement, half a dozen or so of them.

Mice absolutely LOVE fiberglass insulation, so avoid that for starters. Rock wool (Roxul) is perhaps the best but it is quite a bit more expensive.
 
I got the brass mesh it's really great. Flexible you can stuff in just about anywhere I would think- but have yet to try it. I have some Great Stuff for pests which I will use as well. I also have silicone, so I think I have all of my bases covered.

Now to start finding the areas where they get in. As long as they can't climb siding I might be pretty successful.
 
I have found it is practically impossible to keep mice out of our house. I don't know how, but they find their way in. I keep a trap line going in the basement, half a dozen or so of them.

Mice absolutely LOVE fiberglass insulation, so avoid that for starters. Rock wool (Roxul) is perhaps the best but it is quite a bit more expensive.

What about using rock wool on the walls of the 1st floor of the barn and the fiberglass for the ceiling? They would definitely have to climb up the wall to get there as there is no other way in.
 
I would suspect that once they find the fiberglass they will become permanent residents.

Friend of mine has a camp in the woods. He put fiberglass in the ceilings & walls when he built, years ago. He finally had to gut the place & get rid of the fiberglass, the smell was just getting too bad. He didn't bother putting any insulation back in, he just put a layer of OSB up on the inside. Has had no more mouse problems.
 
I've replaced all the FG in our basement with panel or spray foam and Roxul and our mouse issues have decreased to almost nothing.
A lot of that may be attributable to the air sealing done at the same time though.
 
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I would suspect that once they find the fiberglass they will become permanent residents.

Friend of mine has a camp in the woods. He put fiberglass in the ceilings & walls when he built, years ago. He finally had to gut the place & get rid of the fiberglass, the smell was just getting too bad. He didn't bother putting any insulation back in, he just put a layer of OSB up on the inside. Has had no more mouse problems.

Is that like particle board sheets? If so, that would definitely be a code issue when I put my heater in.
 
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