Hot Roof Elevation

[2204z]

If your metal sheet roof is hot because of insufficient insulation or no insulation. Does it make sense to make the roof higher in elevation so the heat won't be felt near the occupants below?

 

[jimstructures]

2204z,

Do you understand how heat radiates from a hot source?

Jim.

 

[msquared48]

Op: only if there are no sidewalls that will contain the radiated heat if present.

Mike McCann, PE, SE (WA)

 

[CBEngi]

I don't understand much about heat radiation, but it would seem more logical to add more insulation to the roof/metal decking then to actually raise the roof, or increase the ventilation to remove the excess heat.

 

[BUGGAR]

Probably not relevant but if you can put a trickle irrigation system at the peak of the roof, the evaporating water will drop the temperature significantly.

 

[2204z]

what would be a good insulation to use?

 

[jeffandmike]

This doesn't make sense. Your roof is probably hot, generically speaking, because of heat from the sun... not "because of insufficient insulation or no insulation".

In all seriousness, additional detail should be provided. For example...

- Is the building entirely enclosed, or is it open to the outside?
- If entirely enclosed, is the space conditioned?
- What is the square footage of the building and/or plan view dimensions (i.e., are we talking about a 100 sq ft shed or a 10,000 square foot office building)?
- Where is the building located?
- Is this a new building or is it existing construction?
- How high is the roof to begin with?
- How tall is your average occupant?

Ok... admittedly being somewhat ridiculous here, but there are potentially a lot of factors to be considered in order to make the decision. If you provided more details on what you're actually doing, you might get more and/or better responses.

 

[Ron]

No. It makes no sense.

 

[thaidavid40]

Yes, the further the source of radiant heating is from the personnel feeling the heat down at ground level, the less of that radiant heat they will perceive. That's simple physics. Moving the roof higher (farther from the floor level personnel) would accomplish that. HOWEVER, for reasonable distances and dimensions in a typical building, you won't get much bang for your buck this way. If there is a ridge vent on the roof, you might get a slightly-increased draft effect through it, but probably not enough to notice. The best way to stop the radiant heating on the underside is to either cool the top side (as in a swamp cooler, as BUGGAR suggested), or else insulate the underside, to interrupt the radiant energy flow.
Dave

Thaidavid