Rooms over partial crawl space cold

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bosco

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My house is a ranch and has a full finished basement. Except for one section it's a crawl space with dirt floor wall are insulated with foiled foam board. The two bedrooms over the crawl space get colder than the rest of the house. What steps should I take?
 
bosco, are you noticing that the floors are cold or just the rooms? Are there registars for the furnace that have been closed? Are there foundation vents in the crawl space? Is this something that just recently happened or has this been happening? Have squirrels or other animals caused any roof or wall damage recently?

Oh yeah, :welcome: to House Repair Talk!
 
oldognewtrick, The rooms temperature gets much colder if the doors are kept shut. The registers are blowing heat. There are no crawl space vents but my basement is deeper than the crawl space and I have to climb up the poured wall to access the area. No signs of animalsor other type damage. This has been a problem since I moved in. Thanks for the quick reply!
 
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You have a mixed bag here. If the foundation walls are insulated the space should be conditioned just like the basement but to do that you should have the floor sealed so moisture can't come up from below. If you insulate the floor the subfloor is the vapour barrier and you need to vent the crawlspace. Maybe all that is required is return air vents from these rooms back the the return ducts, you can't pump air into a closed room if the air has nowhere to go.
 
Keep in mind that heat always moves to cold.
You are heating the room, the heat disappears into the ceiling, then the walls and finally the floor.
Wherever you place your heating, most heat is emitted in straight lines and then moves by convection.
Think of a Thermos flask the contents are warm, the heat is retained inside the Thermos by a vacuum, the only heat loss is via the thin walls where they enclose the stopper.
To keep the heat inside your room, you need to insulate and the best way is to line the ceiling, walls and floor with sheets of polystyrene, glued to the room side of the ceiling, walls and floor. This keeps the heat in the room.
If you place the insulation below the floor, the heat from the room, warms the floor, the joists and is moved by conduction to the cold air outside the room.

By having a fully floating floor, you save heat have warm feet and save money.

You insulate by covering the existing floor with sheets of polystyrene, then you lay a new floor, of t&g, glued floor boards or OSB boards over the polystyrene making sure that the new floor does not touch any part of the existing home. This keeps the heat in the room. Refit the base boards making sure they do not touch the new floor.
 
I would put a 6 or greater mil poly on the dirt floor and insulate the floor joists along with insulating the walls which I think you have done already
 
I would put a 6 or greater mil poly on the dirt floor and insulate the floor joists along with insulating the walls which I think you have done already

Yoiu always want air behind insulation so if you insulate the floor the area should be vented.
 
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