Unique insulation question

[premis]

I'm currently building a house. I have a 14x30 basement storage area that is under the back part of my garage. The garage slab will have hydronic heat, 2" foam board under the slab, vapor barrier under the foam, then precast concrete. The storage area ceiling is the bottom of the precast concrete.

I'll have hydronic heating in the basement storage area too, it's really just a storage area but I want to keep it above freezing (probably 45 degrees). The garage floor above will always be kept at or above the temp of the basement shop.

So, my question, should I bother with insulating the ceiling (bottom of the precast) in the basement storage area? Or would that be a waste? The walls in the storage area will be insulated.

 

[Copymutt]

I think the old adage, heat rises, would be your friend here.

 

[premis]

I think the old adage, heat rises, would be your friend here.

But the space above where the heat would rise to would be hotter than the lower space, so doesn't that mean that I wouldn't really lose much heat in the basement storage area? Plus, there is 2" foam board between the slab and precast, so some heat might go into the precast but then the foamboard should block it.

 

[NUTTSGT]

Sounds like there is insulation already there under the slab/precast.

Are the exterior basement exterior walls insulated ?

 

[premis]

Are the exterior basement exterior walls insulated ?

Yep, all 4 walls are insulated.

 

[yeldogt]

What are you going to use the storage area for --- always for storage?

I don't understand how they will be building the garage slab and it's insulation.

Radiant is not the best for keeping things 40 degrees .... you really can't control the water temp down that low. There is no way to be making/moving 50 degree water around.

 

[NUTTSGT]

Yep, all 4 walls are insulated.

Then I would simply put a box fan in there on low speed to keep the air moving around.

 

[premis]

What are you going to use the storage area for --- always for storage?

I don't understand how they will be building the garage slab and it's insulation.

Radiant is not the best for keeping things 40 degrees .... you really can't control the water temp down that low. There is no way to be making/moving 50 degree water around.

It will pretty much just be used for storage. It has a garage door to the outside so we will keep lawn equipment in there and other larger items. We will also use it a little for overflow storage from the house storage room. And I plan to put my air compressor down there and run Maxine air pipe up to the garage.

They put precast concrete spans on top of the storage area, then put down 2" foam board them pour the garage slab on top of that.

My dad has radiant in his pole barn and he pretty much always keeps it between 45-50.

 

[Chris705]

A T-stat on the wall will control the flow of hot water (Probably at 100 to 120 degrees) when t-stat is satisfied water stops circulating thru slab and heat source turns off. Basic hydronic heating....there could be a little over run of temp but only a couple of degrees.....fluid won’t continuously flow thru the slab

 

[spudley]

If this storage area is below grade the area will stay above freezing without heat. With the hydronic above I'd follow NUTTSGT recommendation of running a box fan.

I have a 24' x 34' 12 course basement room under my precast garage floor that I heat when needed with an 8' electric baseboard.

Insulated walls/ceiling and without any heat on the room stays about 45-50 degrees.

 

[56Mark]

I don't know where you are but my basement is not insulated and mostly underground, two garage doors and it never gets anywhere near freezing down there. It is 12" block filled with concrete. We don't have too many days where it stays in single digit temperatures or below though. Occasionally negative temps, but rare and not for long. Point is, if your underground and insulated is it going to freeze?