Refrigerated conc slab

[rittz]

We are designing a concrete slab for an ice rink in which the cooling pipes are embedded in the concrete.
Below the slab is 3" of styrofoam insulation. Below the insulation are heat pipes.
There appears to be a difference of opinion among my colleagues.
Should there be a vapour barrier
1. under the insulation,
2. on top of the insulation,
3. both top and bottom,
4. none at all?

I have heared each of these options as being correct ??
The insulation is hi-density Dow type 4, R14, 30 psi

 

[steellion]

In wall sections, the vapor barrier is always to be on the "warm" side of the insulation. I imagine this would be no different. Use only one vapor barrier, or else you risk trapping moisture with no way for it to get out.

 

[dik]

Is the rink to be used all year round? Insulation sometimes doesn't help with long term freezing... the soil beneath will freeze over a period of time... Can you circulate the fluid from the cooling process beneath the slab and insulation?

Dik

 

[rittz]

You are absolutely right Steellion about wall sections and I wonder if for some reason it might be different because of the refrigeration or maybe even because of the high density insulation.

 

[rittz]

Dik .... the intention is to use it all year round and also to take the ice out for some extended periods of time winter or summer.(trade shows etc).. maybe even all summer many times. The coolong pipes are only in the concrete. The heat pipes which are below the insulation circulate heat all the time by bthermostat control

 

[BAretired]

If you plan on using a vapor barrier, it seems to me it should go on the warm side of the insulation, i.e. under the insulation.

The attached advertisement seems to indicate no vapor barrier at all, but I believe their product is waterproof. They do mention something about water draining down between joints in the insulation.

It might be wise to research the subject a bit more. See what others are doing.

BA

 

[rittz]

Thanks Ab I agree. The advertisement however does not address the issue from the standpoint where there are heat pipes below the insulation which deals with the frost issue.

 

[VAD]

The use of insulation is likely to prevent frost heaving by restricting the depth of frost penetration. Hence it is likely that frost heave issues are anticipated. The use of the vapour barrier is to prevent moisture from moving upward. In this case where the equilent depth of frost free soil would be about 6 ft, it is doubtful that this vapour barrier would be required. Anyhow, it may be prudent to still install same but belwo the insulation. Vapour barrier below insulation or none at all of the 4 would be my choice.

The interesting aspect about the use , non use etc of insulation requires asound understanding of the rink operation processes and the soil and groundwater conditions.

 

[JAE]

Here is a detail we've used on refrigerated and freezer warehouses. VB below the insulation:

 

[BAretired]

JAE,
Don't you think there is a difference between freezer warehouses and an ice rink? In the case of a rink, the floor is being flooded with water regularly, building up a thickness of ice.

At other times, the rink is permitted to thaw out, permitting water to migrate through the concrete floor and rest on the vapor barrier.

Perhaps it would be better to skip the vapor barrier, use waterproof insulation and drain any excess water away using an underdrainage system.

BA

 

[JAE]

I suppose it depends on whether the rink has an impermeable coating.

 

[rowingengineer]

I found this instresting when I had to do a prelimary design for an ice rink, never did the final design, so I have no experinace to pass on.

Arguing with an engineer is like wrestling with a pig in mud. After a while you realize that they like it