Insulation for interior room

[kwbretired]

How much humidity do tou have up there in New York. I found out the hard way if you seal the concrete & don’t condition the living space you will have moisture problems & potentially mold issues. My living space was fine until l decided to seal the concrete. With the high humidity, it would condense at night & just sit on the sealed concrete. It eventually started to mold everything- walls, furniture, etc. l would only be there every few months so the space was not conditioned continuously. I had to buy a diamond wheel for my grinder & grind all the sealer off of the concrete sonthe water would have a place to go when it condensed. Problem solved. I would recommend if you seal the concrete either by sealer or flooring to have the space continually conditioned to avoid a costly mold problem.

 

[s219]

How much humidity do tou have up there in New York. I found out the hard way if you seal the concrete & don’t condition the living space you will have moisture problems & potentially mold issues. My living space was fine until l decided to seal the concrete. With the high humidity, it would condense at night & just sit on the sealed concrete. It eventually started to mold everything- walls, furniture, etc. l would only be there every few months so the space was not conditioned continuously. I had to buy a diamond wheel for my grinder & grind all the sealer off of the concrete sonthe water would have a place to go when it condensed. Problem solved. I would recommend if you seal the concrete either by sealer or flooring to have the space continually conditioned to avoid a costly mold problem.

That is more about the temperature I think. I had the same issue in my garage, which has plastic vapor barrier under the concrete (no getting rid of that!). The floor stays cool year round, due to ground temperature making the slab cool. Thus any moisture in the air is cooled down near the floor and will want to condense, etc. I had to put a de-humidifier in the garage to deal with the problem. No doubt it was exacerbated by the fact that the garage is insulated and the construction is tight.

 

[AndyMA]

Thanks for all the replies: To answer to the questions:

Location is Western New York - Great Valley - can get quite cold
I have about 4’6” head space up top - thought about a mattress or two for summer night crashing - need to build stairs
Eventually will run a line from propane tank to room for heat -
In summer just open windows and maybe a screen door in back - there are two windows and a service door exit
I am leaning towards the rigid foam and some cheap flooring

Thank you again.

As a certified energy auditor who has insulated many concrete floors in New England & New York the rigid format is the best idea,
I would not lay cheap flooring over it with out a layer of plywood. Andy heavy object falling on it would dent the floor & foam,

Andy