[CTroxtell]

My 1800 sq/ft living area sits on top of a 2600 sq/ft garage, the bottom of my roof line sits at the bottom of the 2nd floor. I've noticed especially when it's cold outside and I walk down my dormers I can feel the cold air being sucked in to the living space around the floor molding by my hardwood floors. What would be the best/smartest thing to do here? As my overhang/eve on my roof pulls air in it is in the same cavity that my flooring is in.

 

[joecaption]

Can not see your house from here so some pictures would help.
Is there not 5/8 fire rock on that ceiling and any walls abutting the living space in the garage?

 

[CTroxtell]

I will try to get some pictures when I get home later. Here is one I took inside my garage some time back when a pex pipe ring busted in the ceiling https://goo.gl/photos/9TVnU72VEgyTcXS8A
The gypsum board is attached to upstairs floor joist but does not extend any further than that, from floor joist to the subfloor there is 20", joist were engineered to support house weight with no supports in the middle of the basement. From what I can see the bottom of the joist sits on top of the cinder block, at this point the roofing starts and there are 4 dormers on each side of the house. I was thinking I might have to pull up all of the moulding around the floor and some of the hardwood and caulk all the joints but wasn't sure about expansion of the wood.

 

[Mingledtrash]

I will try to get some pictures when I get home later. Here is one I took inside my garage some time back when a pex pipe ring busted in the ceiling https://goo.gl/photos/9TVnU72VEgyTcXS8A
The gypsum board is attached to upstairs floor joist but does not extend any further than that, from floor joist to the subfloor there is 20", joist were engineered to support house weight with no supports in the middle of the basement. From what I can see the bottom of the joist sits on top of the cinder block, at this point the roofing starts and there are 4 dormers on each side of the house. I was thinking I might have to pull up all of the moulding around the floor and some of the hardwood and caulk all the joints but wasn't sure about expansion of the wood.

I would see if you can access the area from the attic and use expanding foam before you start pulling up hardwood. I would check the sill seal between the cinder block and wood as well.

 

[CTroxtell]

I would see if you can access the area from the attic and use expanding foam before you start pulling up hardwood. I would check the sill seal between the cinder block and wood as well.

The sill seal will make no difference honestly. The roof line sits at the floor level which is also where the sill of the house sits on the block. So the air will still get drawn into the empty cavity in the wall because the roof vent is between the sill and the roof. You can see in my photos https://goo.gl/photos/W6ZYqqBn5qyj2HV77 I can crawl into the cavity and see the daylight from the roof overhang vent.

Talking with a construction friend he recommended cutting into the gypsum board to get into the empty cavities in the wall and sealing the floor from inside the cavity instead of pulling up moulding and flooring.

 

[Mingledtrash]

it would be much easier to pull all the insulation out of the back side of the wall than to cut open the dry wall.

Talking with a construction friend he recommended cutting into the gypsum board to get into the empty cavities in the wall and sealing the floor from inside the cavity instead of pulling up moulding and flooring.

what about between the bottom plate and subfloor you wont be able to access that from a hole in the wall.
Another thing to keep in mind is, that for the cold air to come in, the hot air must be going out somewhere most likely around a window or light fixture.

I still maintain that your first step is to pull back all the fiberglass insulation from the wall and floor against the dormers from inside the attic and seal every crack and crevice with a can of expanding foam.

 

[SeniorSitizen]

For cold air to enter the structure, it's loosing warm air somewhere above the cold entry point. For every out-ee there is an inn-ee attempting to equalize pressure.

 

[CTroxtell]

If you look at the picture of the outside of my house, starting at the gutter if you follow the roof line up till the 1st change of angle on the roof. Starting from this point is where most all of the walls inside the house end(the angle of the roof cuts access off between the roof and the walls) except for the dormers. There is dead space inside the walls due to the support structure of the joist. From the attic the only thing you can access is the ceiling of the main house, the dormer ceiling has no access. My 2600 sq/ft garage below the living space is finished gypsum board. Leaving the only option to access the dead space in the walls is to cut an opening in the drywall which you could also put some boards in once opened up and have more storage space.

For cold air to enter the structure, it's loosing warm air somewhere above the cold entry point. For every out-ee there is an inn-ee attempting to equalize pressure.

Yeah, I'm an HVAC/R Tech. I was just trying to start eliminating air infiltration into my house and trying to find the best way to seal the house as I definitely have a house design that no one else has.