Foam and Batt Insulation

I noticed within an attic area that the homeowner has R-30 Batt Insulation and also has blown in Foam insulation. I was under the impression that the attic become air condition space when the foam is applied and all the openings within the attic are sealed.

How can the attic breath if there is Batt insulation on the ceiling and foam insulation on the truss work?

All knowledge in this area is appreciated.

Thanks in advance for your help.

Do you have any pictures you can post?


Here are a some different pictures of the areas of concern. One house had batts and the other a combination of batts and blown with the foam insulation.

Was there an air exchange system. It is called a hot roof. But you need a system to exchange air such as bathroom fans on timers…at the most basic level to an actual air exchange or air to air system. Did you have any of that. Manual bathroom fans would not be enough as the human factor (people not using them because they think they are wasting money and energy). They need to have a level of automation.

There was not any sort of air exchanger present for the residence. With the batts there, there was no air movement into the attic space and that is why I’m calling it into question.

FYI The insulation won’t stop air movement, hence air barriers. But it still needs some type of air exchange.


Construction down here (SouthWest FL) is slightly different from the northern region of the country and they don’t use any type of air barrier down here. I was concerned with the air movement (might not stop it completely but will not allow for proper flow) because during our exceptionally hot summers that attic needs some type of air, and typically the air conditioning from the residence is what keeps the temperature down.

I appreciate your input and hope you can provide insight into this issue

Totally understand that things are done different in Florida. I was just stating that insulation won’t stop air movement.
Go to your control panel and put where you are from it will help people to help you.
Yes it is a conditioned space with the spray foam on the roofs deck and I am sorry I can not find anything about the insulation just that there can not be a vapor retarder on the attic floor so as to allow any humidity build up in the attic to dissipate into the home. That said is the bat insulation paper faced? Also is it closed cell or open cell on the roof sheathing?

The batt insulation has the paper facing the cool side (interior, as it should be down here) and the foam is open cell on the sheathing.

Open cell is an air barrier but not a vapor retarder, the paper facing on the fiberglass insulation acts as a vapor retarder. So any moisture that gets in to the attic area will diffuse through the open cell foam. So yes the insulation should be removed to allow for good heat transfer and any leakage pathways from high moisture areas below should be sealed.
A blower door test should be performed to ensure proper sealing, and humidity should be monitored such as with remote desktop monitor, or someone could just throw money at it and directly condition the attic.

I am not an expert for sure and up here we should use closed cell so my knowledge is limited and there are plenty of great articles on this especially for your climate. I hope what I provided will help.

Your help is always appreciated. Thank you for the comments and feedback