sub flooring insulation Question?

I had this guy to call the other day asking a question about his insulation in his crawl space.He had new ducts and plastic vapor barrier installed also insulation in the subfloor.His question was what side of the insulation is supposed to be exposed the paper side /or insulation side buy code? any answers?
Ihave though paper side showing with metal support between joist.*


Kraft paper and / or plastic vapor barrier must always face the warmer area.

Mr. Decker is right!

That, of course, is for the crawl space.

Unfortunately, too many people think that it applies to the attic, too.

At an inspection last week we took the picture in the attic. We noted during our verbal wrap-up that the insulation had been installed improperly. The seller was there and took us to task, stating that “the paper must always face the warmer area.” “Well not when the manufacturer installation instructions are printed right there on the paper and state otherwise.” “Well, I’ll be damned,” said the seller, and then apologizing for his profanity since there were several ladies present.

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In the attic on the ceiling, vapor barrier towards the warm area. In the attic between the rafters, just plain silly without a vent behind it. If the insulation is placed between the rafters, the attic is the warm area.

How I see it too. :wink:

In this case, insulation would be wrong using those general guidelines. Always remember that those are general guidelines and that the manufacturer’s installation instructions will trump any general guidelines.

I got ask, does it not say for most applications apply this side (paper) toward living space? in the photo you sent? was this insulation in the roof rafter or on the ceiling?

This insulation was in the attic. The major problem here is that there were two gas-fired furnaces in the attic, so the “The facing on this Fiberglass insulation will burn. Do not leave exposed” and “Protect facing from any open flame or heat source” trumps everything else. Since it was brand new, the seller also had the manufacturer installation guide which confirmed proper installation in an attic (or garage) with gas-fired appliances present.

If ther was open flame in tha atytic, that was not a furnace, it was a camp fire.

Seriously, I see them build little rooms in attics (no drywall, but studs with insulation) and the face the paper towards the furnace. HVAC guys (those who are not clueless) tell me that there is no need for the insulation. Attic units should be cat 4 with intake air piping. These are sealed and there is no problem with freezing or the like. There is also no need for insulation in their ‘rooms’.

Some AHJs around here call for a room with fire rated drywall. In this case, it makes no problem if the walls are insulated. It won’t help anything, but it won’t hurt.

Just a case of new technology being ahead of most installer’s learning.

I inspected a building recently which had insulation between the roof trusses, and I find it quite frequently here in the southwest.

There was no paper face on the insulation and absolutely no ventilation in the attic besides the normal gaps at the soffits, there was also blown fiberglass on the ceiling of the second floor, about a foot.

The split system Heat Pump distribution duct had a four inch flex/duct with a register attached in the center of the attic.

It was quite nice in the area to tell you the truth. About 60 degrees and it was almost 80 outside.

The HVAC installer balanced the system to allow the attic to be basically conditioned…works very well.

I think we will be seeing this more often in the Southwest. Makes a lot of sense.