View Full Version : 4"-5" gap between garage dry wall & concrete floor

01-12-2013, 06:08 PM
Hi All - looking for some help with a problem in the garage. We've been experiencing a mice problem and the exterminator is telling us that the mice are coming in via the garage. There is a 4-5" gap between the dry wall and the concrete floor. See attached picture. Behind the drywall, there is a 2-3" space (no insulation) between the drywall and the interior wall of the house. It looks as if the mice have been entering the house via the space and literally dropping into the area behind the wall into the basement directly below (we've caught a few there). I don't want to keep on throwing out more mouse traps and killing mice everyday so my questions are:
1) Is there a reason why the drywall doesn't go all the way down to the concrete floor - water/moisture?
2) What's the best way to seal this space off?
3) Should the space between the garage dry wall and interior home wall be insulated? If yes, how?

Appreciate any and all advice!

01-12-2013, 06:19 PM
Doesn't code dictate that your attached garage must be isolated from the house?

The space between the garage and your home should be treated like an exterior wall.

01-12-2013, 07:32 PM
I would mark the drywall at about 5.5 inches above the concrete and and carefully cut it off the wall. Making nice clean straight cuts will be a bit time consuming but can be done.

After removing the narrow strip of drywall you can replace or should I say fill the void area with a 1x6 or if you like 2x6. Nail them in place, seal with a good quality sealer and you should be done.

01-12-2013, 08:32 PM
Try 1/2 x 10" hardie board that way you can still get it wet and not worry about it.

01-12-2013, 08:42 PM
Coleman's solution is best, plus it makes for a nice bumper at the bottom giving the walls just a touch of xtra proction. I'd also add using pressure treated with whatever dimension lumber you end up using since it's touching concrete.

alternatively (if the molding is wide enough):

01-12-2013, 10:07 PM
Yes, water and drywall equal gypsum soup and mould, so drywall should never touch a concrete garage floor. Whoever installed it got lazy it seems. There should have been some type of baseboard between the two.

I like the pressure treated 2x idea. You can paint PT lumber as long as you use a good quality primer, and mice don't like to chew them due to the chemical aftertaste.......

01-13-2013, 10:04 PM
Am I going to need to use concrete nails to attach the 2x6 to the concrete/masonary wall? Do I need special tools for this?

Thanks everyone for the suggestions.

01-13-2013, 11:25 PM
Actually, why not nail or screw the 2x6 to the wall framing? It doesn't have to be attached to the concrete, only firmly abutted against it. I assume you won't have significant heaving of the garage slab?

If there may be heaving of the slab, then you do want to attach it to the concrete and leave the part touching the framed wall able to slide. I'd use a powder actuated tool, eg Hilti, Ramset.

01-14-2013, 12:13 AM
Cut it a few inches up, fill base with steel wool (think roxul is supposed to also keep the mice away?) Then reinstall one of the newer waterproof drywalls... problem solved

01-14-2013, 01:27 AM
I'd go with colmans solution.
Just nail or screw it to the framing.
Even some construction adhesive behind it wouldn't hurt any.

01-14-2013, 08:11 AM
How about some aluminum strips from just above the concrete floor and secured to the wall. You can buy them at most box stores, or get end of rolls from a gutter fab company.

01-14-2013, 08:20 AM
Before you start trying to secure that drywall, let me ask this question.

The wall between the interior of the house and garage doesn't have any insulation in it ?

If there is no insulation, I'd be ripping the drywall down and insulating it or drilling holes and filling with blown-in insulation.

01-14-2013, 09:24 AM
It seems to me that the rodents should not be getting in the wall to start with. Start with the siding. Then move inside and address that issue.

01-14-2013, 10:08 AM
Like Nut said, If the faces and interior of the hosue it should have insulation. I would take the drywall down on the garage side and put up insulation. Recover it in dry wall to the proper length.

If you want less mudding and taping I would cut out a strip along the bottom and attach new dry wall so it is the proper lenght. In between each set of studs cut a small hole at the top and do blow in insulation and patch the hole. Paint the wall and finish it out with Pressure treated moulding or regular molding. I would seal it to the wall and floor with caulking so the mice can't get in there and mess your insulation up. It will likely make the house and basement warmer.

The insulation is Something you need to do anyway if the wall any kind of interior wall. Look around the garage and take any food source (cat or dog food) off the floor and put them in sealable containers. Lay the traps in the garage or get a house cat if you don't already have one.

Also check around the outside of the garage and look to see how they are getting in there.

01-14-2013, 11:25 AM
This is bothering me. I would 1st get the garage sealed up,the mice are entering somewhere from the outside. You have a siding or foundation issue. Then after that issue has been taken care of move inside. Just nail,screw,glue or whatever a trim board ,6 inch to the base of the wall. Leave it off the floor a nail width so it doesn't rot. Then finally have insulation blown into the tops of the wall. They will have to drill holes but it will be worth it.

01-14-2013, 02:18 PM
Ok, first, like others have said, the wall between your garage and house should be double drywalled and insulated like an exterior wall. There should be no airflow b/w the house and garage.

Second, the 2x6 idea is a good one but make sure you get pressure treated. Partly to handle the moisture, partly because concrete should only come in contact with pressure treated. It will cause untreated wood to rot.

Third. Figure out how the mice are getting into the garage. Stop that first. The worry about how they are getting in to the house.

In the mean time, traps, poison, and a cat. . .

01-14-2013, 03:25 PM
Ok, first, like others have said, the wall between your garage and house should be double drywalled

You are the only one that says DOUBLE dry walled.
Why is that?