Insulation Metal Building - Alabama

[AlabamaGuy]

Hey guys, I had a 30x40 vertical roof all metal building put up a couple years back, now I'm having a slab poured inside it, expanding to 30x50 and enclosing the walls. My contractor wants to use the bubble wrap insulation and I'm hesitant on it. Is there a better option for extremely hot/humid climates out there? It will be much easier to heat in the winter than to cool for 7-8mo out of the year. I'm looking for a product that has all of my barriers built in that the crew can roll out as they install the metal over the frame.

 

[OneOfEm]

The bubble wrap will do almost nothing for insulation. I added a layer under my roof metal to cope with condensation on the underside of the roof panels in the winter, but that's less of an issue down south than keeping cool in the summertime (I'm in NWFL).

I don't know of a product that can be rolled out before the metal is placed that will provide sufficient insulation.

 

[AlabamaGuy]

Is it safe to do the bubble wrap and go back later with fiberglass on top of it? I have heard stories of the bubble wrap breaking down over time, and I don't want to lose my vapor barrier and get wet fiberglass and mold down the road.

 

[timdgsr]

I'm in Alabama too. My enclosed pole barn has a super thin fiberglass insulation with a radiant back. It does almost nothing for insulation, and I would still take it over bubble wrap. Don't let your contractor tell you that it's enough to keep the building cool in the summer or warm in the winter, because it's not. The R values on those radiant insulations are skewed vs. a standard insulation.

If I was in your situation, I would find the proper insulation solution right now, and not try to come back and fix what your contractor should have done right in the first place.

 

[AlabamaGuy]

I totally agree. That's why I'm seeking opinions here. Do I do a tyvek wrap and then traditional fiberglass insulation? I'm spit balling here. I have zero experience.

Perhaps bubble wrap or thin fiberglass first and then traditional insulation over that? I'm closing in 3 sides of this building first, so I don't necessarily need insulation right away but what needs to be on the exterior needs to be done when each wall is constructed.

 

[OneOfEm]

Tyvek would have probably worked better against condensation than double bubble (since it's less likely to break down from the heat) under the roofing. I'm using it under the sidewall metal. I'll do traditional insulation once the building is closed in.

 

[timdgsr]

I do know that Tyvek wrap is not considered a vapor barrier. I don't know if that matters to you, and I know there's a lot of discussion around vapor barrier necessity in this part of the country.

Like OneOfEm posted above, I'm not sure a sufficient insulation is available in a single product that can be mounted between the metal and the girts.

I have seen some thicker insulations with a vapor barrier facing. You could potentially find something similar to what's installed in mine (radiant, fiberglass, vapor barrier/vinyl facing) just thicker? I just don't know how thick you can go and still successfully mount the metal to the girts. Also, the insulation will be squished at each girt, so that's not ideal for insulation either.

What's your ultimate goal for the pole barn? Fully enclosed? conditioned?

 

[My Old Tools]

I'm in east Texas, hot and humid. Mine has 4" plastic backed insulation all the way around, then a second layer in the roof. Works well and I don't get that hot layer of air up high like my last building. Mine was applied before sheeting. In a retrofit, spray foam would get a hard look from me.

 

[Dragfluid]

OP, please get that bubble wrap out of your head. It's a scam.
Lots of opinions here. Here's mine. Look at my build thread to see how I did it.