Insulation Question

[Thomas41]

I am building a 20x20 metal building with one garage door and a traditional door, that is going to finished out on the inside with 2x4’s and either 7/16 OSB or either 11/32 plywood, that will then be painted. When the building was built, the contractor put roof insulation, but did not add any to the walls. When I questioned this, he gave me a list of reasons why…..Among those are he stated that I would not need insulation on the walls, since I am framing them in and further more air raises and my roof is already insulated. He also stated my roll up garage door is not insulated. Finally he said that because of the metal thickness, it would provide insulation as well. As a precaution, I bought a couple cans of spray foam and sprayed all the seams where I could see daylight. We have had some cold windy weather and the building is staying warm (with no heat) and you cannot hear any wind coming through the seams...only around the garage door.
My question is do I need to add insulation and what are the cons of not adding insulation?

 

[Blk88GT]

Where are you located?

 

[Thomas41]

Where are you located?

I forgot to add, I am located in the middle part of Georgia.....

 

[Ksullivan]

Honestly do you heat? does it get cold enough to rationalize insulation or would it be worthwhile to just have a heater that may run more, I know here in NY we NEED insulation otherwise we would freeze!!! If you do insulate I would suggest fiberglass batts. Are you going to use the building for long periods of time in cold weather? Woodshop? Autoshop? All things to consider, If I were just parking equipment in the garage I wouldnt worry about insulation but if it's a workspace I would insulate.

 

[Thomas41]

Ksullivan, Thanks ...The contractor brought up the actual amount of time I would be spending in the the the garage / work shop as well.(Which would not be for long extended periods of times.)

 

[MScott]

Don't forget that without insulation that building is going to be an absolute furnace in the summer, especially in the south. Insulation is as important to keep interior temperatures cool in hot weather as it is to keep the space warm in winter.

 

[Falcon67]

>Finally he said that because of the metal thickness, it would provide insulation as well.

BS - my steel garage door was cold as an iceberg until I put insulated panels in it. The steel braces on the door will still be 20F colder than building air temp when it gets cold here. It also faces south, and the door will get over 120F easy. The HardiPanel wall that faces west is painted gray and runs 130F on warm days. The panels are 5/16" thick - probably thicker than your metal. In the hot summer, I could not put a hand on the inside of the wall until I insulated it. If the building just sits, no AC on, the inside wall temp (west wall) in summer - 5/16 panel + 3 1/2" R-13 + 1/2" OSB = 95 degrees.

When that wall was red on the outside, surface temp would go to 180F. The insulation cut that by half.

I'd insulate, personally.

 

[matouse3]

>Finally he said that because of the metal thickness, it would provide insulation as well.

BS - my steel garage door was cold as an iceberg until I put insulated panels in it. The steel braces on the door will still be 20F colder than building air temp when it gets cold here. It also faces south, and the door will get over 120F easy. The HardiPanel wall that faces west is painted gray and runs 130F on warm days. The panels are 5/16" thick - probably thicker than your metal. In the hot summer, I could not put a hand on the inside of the wall until I insulated it. If the building just sits, no AC on, the inside wall temp (west wall) in summer - 5/16 panel + 3 1/2" R-13 + 1/2" OSB = 95 degrees.

I'd insulate, personally.

^^exactly what I was thinking. Metal provides insulation??? Not in my universe. Here is a link to some R values:

http://metalbuildingdepot.com/aspx/rvalues.aspx