# Cold floor in bathroom above garage



## dartman92 (Mar 23, 2009)

Hi
We built our house 7 years ago in Illinois, our plan has a guest bedroom on the second floor with a full bathroom. The closest and bathroom for this room is partly built out over the garage. During the past couple winters the bathroom seems noticably colder then the bedroom, especially the floor. 

I know we used blow in insulation in the walls, and the ceiling of the garage which is drywalled. The 2 exposed walls in the garage attic have a thin foam board on the back and the garage attic ceiling does not have any insulation. I would like to add additional insulation but have some questions on the best method 

1. I can access the 2 walls above the garage from the attic above the garage (see photo) Can I add batt or foam board insulation overtop of the back of the wall or would I be better to insulate rafters?

2. As my floor is getting cold and the garage celing is finished (attached photo) can I add some foam board insulation overtop of the drywall or do I need to open up the space and add more insulation?

Any advise would be appreciated
Thanks


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## midwestcoast (Jul 1, 2011)

So, is there cellulose blown in those exposed floor joists? It looks like no.
Is the cellulose blown behind the fan-fold foam on the bathroom walls? Again looks like no. 
The floor joists are open to the attic which means you essentially have outside air under the floor of the bathroom.
Is the bathroom ceiling insulated?

Blow cellulose into the floor joists & air seal the joist bays where they meet the attic. Pieces of foam board caulked or spray foamed in place will do that nicely.
I would then add some strapping over the fan-fold foam on the walls for support and fill those stud bays with cellulose.
Then add cellulose above the ceiling as mush as you can while maintaining an air-space below the roof decking.
Should be much warmer


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## dartman92 (Mar 23, 2009)

Thank you for your response.

Per the builder they were suppose to use cellulose blown in to the walls and under the floor (from the garage before they drywalled) 

The garage floor joist right under the build out are closed in by wood, again suppose to be blow in cellulose) the only way to access would be from garage and removing drywall. I would prefer not to remove drywall could I put the foam bard on top of the drywall on the garage ceiling?


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## joecaption (Nov 30, 2011)

Nope, it can not be left exposed.
Look right on the face of the foam.
Produces toxic fumes in a fire.
Amazing to me that there was no insulation in that ceiling with living space above, should have been caught in the insulation inspection.
Garage below should have been fire sealed and insulated before the drywall.


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## joecaption (Nov 30, 2011)

Nope, it can not be left exposed.
Look right on the face of the foam.
Produces toxic fumes in a fire.
Amazing to me that there was no insulation in that ceiling with living space above, should have been caught in the insulation inspection.
Garage below should have been fire sealed and insulated before the drywall.


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## Windows on Wash (Aug 30, 2011)

Put some foil faced foam over it, pull the blockers in the floor joists and blow some insulation in there, seal them back off when done.


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