Morning room with opwn air floor below ?
Hi all,
Got a quick question about my house that I am building. I have a 12 x 16 breakfast room coming off the back of the first floor. The house is a walkout basement affair so that means that this breakfast room is open air under the floor.
Several people, and one respected friend who is a builder, said to me that the floor is going to be cold (Cleveland, Ohio). And the indication was that over insulating would really not do the trick.
So my questions are:
Do you all agree? What kind of insulation should I use (I was planning on fiberglass bat insulation with blue foam board across the bottom of the floor joists)?
My builder friend suggested bleeding off some hot air from the furnace to heat the underside of the floor (essentially, make the floor assembly a little deeper so that the insulation doesn’t hit the underside of the floor and heat that air space just a little). How about that?
I do know that I could do some sort of radiant heat (electric or hot water) but it seems like a little overkill when the rest of the house is getting a really fancy forced air system. But if that is the only good solution, then that’s what I’ll do. I definitely don’t want to have cold floors in this room.
Thanks in advance for the advice all.
Rob Kress
Replies
his suggestion would only work with a positive pressure heating and air system, IMO. Ohterwise, when the blower is off the drafts are increased.
The solution to insulation and wramth is to insulate tightly, not to increase chances for airflow/convection currents to bleed heat away or to let cold in.
I would put Thermax or other foil faced foam up tight to bottom of subfloor and use canned foam to seal edges if needed. Then run unfaced fibreglass about R-19 under that and skin over with whatever material for finish
Excellence is its own reward!
"I definitely don't want to have cold floors in this room."
Coupled with a good insulation package, RFH should eliminate any chance of that.
I agree with you. Had a city row home with an unheated basement. So that was even less air flow than this. Insulated beneath, but the floors were still much colder than the rest of the room. Froze our tootsies even when the radiators were causing our faces to be stuffy hot. To not have a cold floor, I think you gotta put some heat into it. Strikes me as a perfect use for something low-mass like warmboard which will have very little lag time--set a timer on it, and you can warm the floor surface for just an hour or two a day if you wish. And you wouldn't have to size the heater to heat the room...just enough to heat the floor.
Thanks for the replies guys. Not so sure what I'll do yet. Still opinion shopping so to speak. In then though, I'm sure it will come down to me doing it right. I'll just have no choice.
Rob Kress