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Bucks County Bruce
Insulation below subfloor

I'm putting hardwood floors in my daughter's bedroom. Her room is just above the garage and is terrible cold during the winter.

I'm thinking since I have the subfloor exposed and the room gutted, about taking it up (the subfloor) and adding insulation between the floor joists. Thinking that it would be easier this way rather then taking the ceilintg down in the garage and adding the insulation that way.

Is this a good idea? Am I missing something???

HoustonRemodeler
Re: Insulation below subfloor

Good idea. what about a vapor barrier? Where do you live? Bucks CO PA ?(former resident of Huntingdon Valley myself)

Timothy Miller
Re: Insulation below subfloor

Howdy, terrible cold floor, yikes. Easier then pulling floor and installing foam is to remove the ceiling and insulation. Then have 2" closed foam spray applied then filling rest of cavity with fiberglass bats& re dry walling with 5/8". The foam not only will make a huge comfort difference. Best is it seals out any auto off gassing that can leak into the house. The foam is $$ but decreased utility bills - or doctor bills is a great plus.

Timothy Miller
Re: Insulation below subfloor

Also with the ceiling cavity open you can foam any HVAC duct pipe to insulate it makes a huge difference too.

canuk
Re: Insulation below subfloor
Bucks County Bruce wrote:

I'm putting hardwood floors in my daughter's bedroom. Her room is just above the garage and is terrible cold during the winter.

I'm thinking since I have the subfloor exposed and the room gutted, about taking it up (the subfloor) and adding insulation between the floor joists. Thinking that it would be easier this way rather then taking the ceilintg down in the garage and adding the insulation that way.

Is this a good idea? Am I missing something???

Depending on quick you complete the task it may not be a good idea. Otherwise your daughter may be out her her room longer than anyone wants.

Rooms above garages being cold is probably the number one complaint.
There usually are inadequate insulating, air sealing and heat supply deficiencies found to be cause in the space under the floor.

As Timothy posted the better way is to remove the ceiling in the garage and correct the issues from there. This is also the least disruptive for your daughter.
The most effective method is indeed using closed cell spray foam applied to the underside of the floor and to seal any penetrations to the outside preventing cold air movement.
Also, to prevent any emmissions from car exhaust reaching the living space above.
This will also allow you to evaluate the the heat supply that may likely be running in that space and correct if need be.

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