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Posted By: Steven C. Different kind of ? about mice in garage. - Sun Feb 09 2014 01:27 PM
I live along the edge of a wooded area and I have had mice in the garage. I removed anything and everything that they may want to live in and all materials that they may want to build a home with, and a little help from Decon, and since have had no problems.
So I have your typical wook framed construction garage with 2 x 4 walls and 2 x 8 roof rafters with 3/4" plywood roof sheeting. I've never seen it done before, but I want to insulate the ceiling space between the 2 x 8 rafters and then enclose the space, or install a ceiling of 1/4" plywood. I'm pretty sure I can enclose things quite tightly, but mice can get into almost anything if they really want to.
So here is my question. Are mice going to get into the space and set up camp? Is there any reason to believe that they would invade this space any more than they would or could the walls?
Your thoughts?
And to the construction guys out there, what, if any kind of venting would need to be added if I enclose this space?

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Posted By: T-way Re: Different kind of ? about mice in garage. - Sun Feb 09 2014 01:40 PM
Steve:

Mice don't care about insulation. They will build nests in it and drag it anywhere they want. I've had mounds of it behind cabinets against the wall at the floor level.

BTW - you don't want to fill the area in your illustration with insulation. Your roof needs to 'breath' and the vents in your soffits allow air to move up the inside of your roof and remove heat and moisture.

Blocking this area off with insulation will cause mold and rot to the inside of your roof structure.

They make 'baffles' that go into that area and attach to the underside of the roof. The insulation goes 'below' the baffles and across the ceiling joists - not the underside of the roof itself. The baffles allow the movement of the air.

If it was me, I'd do a plywood floor in the attic over the insulation with a drop down ladder for extra storage. Then sheath the ceiling with plywood or similar material.

Sheetrock is inexpensive and easy to paint - but it can crack along the taped seams in a garage as they have a tendency to move around in the wind more so than a house.

Later . . .

Jim
Posted By: gasmansgp Re: Different kind of ? about mice in garage. - Sun Feb 09 2014 01:47 PM
If you fully insulate between the rafters as shown, you will have no ventilation and the heat/moisture buildup will destroy the roof. Vaulted ceilings are nice but you need to frame up one a bit below what your structure wood work is. Thereby eliminating the venting problem. At the eve, where the wall joins the roof line, a hopper vent tube must be installed to keep insulation from closing off the vented area. Common sense stuff. Mice are always a problem. Get a cat. Paul www.severngaspumps.com
Posted By: Steven C. Re: Different kind of ? about mice in garage. - Sun Feb 09 2014 01:58 PM
Originally Posted By: T-way
Steve:
BTW - you don't want to fill the area in your illustration with insulation. Your roof needs to 'breath' and the vents in your soffits allow air to move up the inside of your roof and remove heat and moisture.

Blocking this area off with insulation will cause mold and rot to the inside of your roof structure.

They make 'baffles' that go into that area and attach to the underside of the roof. The insulation goes 'below' the baffles and across the ceiling joists - not the underside of the roof itself. The baffles allow the movement of the air.

Later . . .

Jim


Jim,
that is exactly what I was wondering about. I remember in an old house I had, we added a room with a cathedral ceiling and I remember installing these blue foam like vents that attached to the bottom of the roof sheeting. So I know what your talking about. And I was wondering if this was needed in a garage. And from what your saying that would be a yes. But in my old house there was a ridge vent in the roof and soffit vents along the bottom. Allowing for good air flow. My garage does not have a ridge vent. It has 2 metal type roof vents which i was going to box out so that they still vented to the actual room space.
I do not want to enclose the space at the joists. I dont want to loose that ceiling space for sign display. And because of the low roof angle, I would not have access to most of the created space. It would only be useful in the very center of the structure.
Posted By: gasmansgp Re: Different kind of ? about mice in garage. - Sun Feb 09 2014 02:42 PM
Using the two metal vents to move air out of the actual room space will do nothing to keep the roof dry and cool. If you had designed the roof to be somewhat higher, you would have had the needed space to put in the false roof vault. Unfortunately, this problem has no easy answer. Over time, an unvented roof will decay. I'd forgo the idea to fully insulate the roof rafters, with fiberglass insulation. You might give some thought to using 1" foam held to the bottom edge of the rafters, allowing the air above to be vented? Not the perfect answer but one that will help if done correctly. Paul www.severngaspumps.com
Posted By: JimT Re: Different kind of ? about mice in garage. - Sun Feb 09 2014 03:15 PM
Soffit vents- baffles- then install a ridge vent.The ridge vent is pretty easy-tear off your caps, saw a slot the length of the roof at the peak and install the vent and new cap.
Posted By: Vermonter Re: Different kind of ? about mice in garage. - Sun Feb 09 2014 03:25 PM
I have quite a bit of knowledge of roof venting in the northeast where ice dams are more of a concern, but you still need to vent properly in your climate.
By far the easiest solution would be to install ceiling/floor joists and insulate between them, then sheetrock. Venting would not be a major concern, but I would add gable vents to pull in outside air. If you want to do the cathedral ceiling, you need to install the Styrofoam baffle (called proper vent around here)the entire length of the bay and add soffit vents and a ridge vent. If you have any hips and valleys that will not be vented by the soffit and ridge vents, drill 1 1/4" holes along the rafter so it vents into the adjoining bay.
If mice can get in your garage, then they will get into insulated rafters. Insulation doesn't bother them, so seal all possible entry points and don't forget the seal under your overhead door where they commonly get in in an otherwise new sealed building. Good luck!
Posted By: Dick Bennett Re: Different kind of ? about mice in garage. - Sun Feb 09 2014 04:48 PM
Sure Cure

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Posted By: Steven C. Re: Different kind of ? about mice in garage. - Sun Feb 09 2014 06:10 PM
Okay, So ridge vent, soffit venting and baffles it is. I see no way of heating the garage all winter without some kind of insulated ceiling. It would cost a fortune otherwise. My goal is to create a nice clean year round space.

I'm getting what you are all saying and I'm glad I asked. The roof must be vented.
This is a picture when I had just finished the process of enclosing the car port protion of the structure. As you can see, it is a hip roof with only 6'-7' ridge along the top. But I think I'm understanding that all cavities have to have air access to the ridge vent. Looks like I'll have to drill quite a few holes.

Thanks all for the help!! As for the possible mice? I'll just have to stay on top of it I guess.

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Posted By: Loyd Pierce Re: Different kind of ? about mice in garage. - Sun Feb 09 2014 06:33 PM
Mice are very thankfull for the up garage door. Takes all the guess work out of how to get in.LOL!
Posted By: oilmanpat Re: Different kind of ? about mice in garage. - Sun Feb 09 2014 08:08 PM
I use stuff in pellet form called One Bite for my mouse problem. Seems to do the job quite well.
Posted By: T-way Re: Different kind of ? about mice in garage. - Mon Feb 10 2014 01:26 PM
Steve:

If you really want the shop to be warm in the winter, insulate all the walls and the rafters and install finished walls and a ceiling. Paint it all then move in your collection.

I personally like the look of a museum layout instead of a bunch of stuff up against open walls with the studs showing. Spend a bit of money now and you will have a much nicer display area forever.

Later . . .

Jim
Posted By: JimT Re: Different kind of ? about mice in garage. - Wed Feb 12 2014 12:41 PM
Steve, they recommend a lot of insulation for attics and ceilings in our area-like R50 or R60. You will have a real tough time achieving that with a vaulted ceiling. I'm not sure but I think it would be like 18-24" of fiberglass. Our first house was a bungalow and I finished the attic. The roof rafters were only 2x6s as I remember and were already sagging quite badly. I solved both problems (no room for insulation and the sag) by reinforced them by screwing I think 12" high 1/2" plywood alongside them with a 2x2 screwed to the bottom for something to screw the drywall to. I started on each end then strung lines to fill the rafters in so the ceiling would come out in a nice plane. I couldn't go any more because there was only so much headroom.You have to be patient and meticulous with the insulation. With the shingles, plywood, fiberglass, visqueen VB, and drywall I'm sure I probably only got R35 or 40 but it was always comfortable and our heating bills went way down because there was very little original insulation in the floor.
Posted By: Steven C. Re: Different kind of ? about mice in garage. - Wed Feb 12 2014 01:01 PM
Wow Jim, that sounds like a lot of work. Far more then I would be willing to do for a garage.
My cousin has the same basic garage but he put in blown insulation. Which to me looked like hell!! I could never stand to look at that. But he said it allowed him to keep it a constant 60 deg during the winter months and his bill only went up like $20 a month. And when he went out there, he just turned the heat up a bit. That is all I'm looking for.
I wonder at what temp difference does condensation begin? I mean if you keep it at 50 or 45, and then turn it up to 70, will condensation form? Hmm...

My plan is to install all the venting and insulate it as best possible and put a 1/4 or 3/8 ceiling in and paint it all white.
I'm hoping I can seal the space everywhere well enough that should any mice show up, they can't get into the cavity.
Posted By: Savinsam Re: Different kind of ? about mice in garage. - Wed Feb 12 2014 01:16 PM
DB, that unset trap isn't going to catch anything!
Posted By: JimT Re: Different kind of ? about mice in garage. - Wed Feb 12 2014 01:20 PM
Oh, for sure, because you dont need it to be flat or any of that. But from the looks of it You are only going to get about 6 inches of insulation in there.Just an idea to get more Rs. You could also insulate between rafters then glue and screw foamboard to the rafters then glue and screw your drywall to that. You will need a good vapor barrier behind your drywall. ANY condensation will accumulate and then freeze eliminating insulation and causing problems with mold and rot. Also it isnt just the change in temperature in the room when you raise the thermostat.. As the heat passes though the barrier( drywall, Insulation, plywood) it leaves behind the moisture particals that are present (in any air) that cant pass through with it. Heat goes toward cold. Then it will reach the cold and freeze.
Really even with 6" of insulation and then turning up the thermostat it will help a lot.(My disclaimer-Im not an insulation expert-just a think so-lol. Some people say dont use a vapor barrier-lol
Did your cousin use the foam? Drywall is definately cheap and makes all the difference in the world.
Posted By: JimT Re: Different kind of ? about mice in garage. - Wed Feb 12 2014 02:01 PM
I just noticed youve got a hip roof. You might have kind of a tough time venting that with a cathedral ceiling. As has been mentioned you will have to do some creative drilling.
Posted By: minuteman Re: Different kind of ? about mice in garage. - Wed Feb 12 2014 07:04 PM
dont know if it will help but the expanding spray foam that comes in a can is basically mouse proof...they will avoid it for sure...no chewing or making holes....
Posted By: Steven C. Re: Different kind of ? about mice in garage. - Wed Feb 12 2014 07:10 PM
Originally Posted By: minuteman
dont know if it will help but the expanding spray foam that comes in a can is basically mouse proof...they will avoid it for sure...no chewing or making holes....


Very interesting idea!! Thanks.
Posted By: T-way Re: Different kind of ? about mice in garage. - Thu Feb 13 2014 03:00 PM
Steve:

The spray foam is a great idea - as long as ALL your electrical is exactly how you want it. Once they install the foam, your electrician will have a cow if you want to run some more lines behind the walls/ceiling.

Of course, at that point, you can do conduit and boxes on top of the wall.

Jim
Posted By: Gasman84470 Re: Different kind of ? about mice in garage. - Thu Feb 13 2014 03:35 PM
Steve:
That's how I did my garage for "R" value. A commercial spray foam firm comes in and gets it done in a matter of an hour for a job of that size. Vapor barrier is not needed in that circumstance but as Jim says be sure about your electric wiring because once that stuff hardens its encased everything behind it. Great for R value and critters can't get behind there and cozy in it like they can with fiberglass batting.
Posted By: Cold Pizza Re: Different kind of ? about mice in garage. - Thu Feb 13 2014 03:41 PM
The hell they can't.
I had a company spray my wall pockets last year.
They showed me photos of other customers who had critter damage after they sprayed.
They now offer their customers 2 different spray foams.
One that is bitter tasting and repels critters from chewing through it,and one that doesn't.
You now sign a release if you opt for the latter.
Posted By: Gasman84470 Re: Different kind of ? about mice in garage. - Thu Feb 13 2014 03:50 PM
Hmm in a space that's completely filled with foam, the little buggers got in? Well we never had a discussion with our contractor over different critter repelling formulations. Sounds like I better keep an eye out for their presence.
Or maybe they were giving you the upsell speech for the more expensive foam.?
Posted By: 1968pickup Re: Different kind of ? about mice in garage. - Thu Feb 13 2014 09:04 PM
cold pizza is right I work in a grain elevator mice everywere the pest control guy fills voids with spray foam then puts some small fine wire in it and that keeps them out he said the regular foam without the wire mice eat right through it may sound odd but it works for filling small holes they like to travel through
Posted By: Vermonter Re: Different kind of ? about mice in garage. - Thu Feb 13 2014 11:02 PM
I have probably used 100 cans of the stuff in my old house. Mostly, the mice will avoid it if they can; however,they have chewed through some holes I filled. I noticed they now sell a formula mice don't like.
Keep in mind if you foam, you still need the baffles. PM me if you want info on spraying foam yourself. I have used Foam It Green which is a do-it-yourself kit that is supposed to be ok for the environment. There are pros and cons using foam vs fiberglass.
Posted By: Steven C. Re: Different kind of ? about mice in garage. - Sat Mar 08 2014 02:58 PM
Roofing experts, this pic is from 1969L88's posting about his new meeting place located in Kentucky. How is it that this structure can get away with the rafters running horizontally and fully insulated. There is no way this set up is vented as has been discussed in this thread. Will not there be a moisture issue? Or is it a none issue becuase of the metal roof? Kentucky still gets cold enough weather I'm sure does it not?

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Posted By: Huskerscott Re: Different kind of ? about mice in garage. - Sat Mar 08 2014 09:07 PM
The air will travel up those ridges in the metal roof for ventilation.
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