Do you have to mechanically ventilate an attic space used for storage?
good4utoo
| Posted in Building Code Questions on
Do you have to mechanically ventilate an attic space used for storage when the whole attic is within the thermal envelope? The roof is 10 inch SIP panels (R-60) and all walls are open-cell SPF.
The owners have asked if there is a code issue here. We can’t find anything definitive.
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Replies
Ann,
No, you don't want to ventilate a conditioned attic. Of course, if the house is very tight, you will want to install a mechanical ventilation system for the occupied areas of the home (living room, bedrooms, bathrooms, etc.). This can be done with an exhaust-only system, a supply-only system, or a balanced (HRV or ERV) system.
If the attic is used for storage, it needs neither fresh supply air nor exhaust air.
The section of the 2009 IRC that provides requirements for unvented conditioned attics is Section R806.4. For more information on this topic, see Creating a Conditioned Attic.