# Can/should I add insulation underneath stationary stairs to my attic?



## Windows on Wash (Aug 30, 2011)

Spaces between conditioned spaces do not need to be insulated but they do need to blocked off from outside airflow. If the attic is vented, they need to be blocked off with rigid foam (with an approved ignition/thermal barrier).

I am having a bit of a difficult time piecing together the pictures. Any chance you can get some wider shots?


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## Gary in WA (Mar 11, 2009)

Without an insulated door/hatch at the top of the stairs, you need to insulate the stair walls, floor, risers/treads, and door since they are coupled to the interior conditioned spaces. You have an effective stairwell heat-sink there... the reason it is warm when you step inside the well. You have no thermal boundary established, air-seal the attic first; http://oee.nrcan.gc.ca/publications/residential/9373

Gary


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## Windows on Wash (Aug 30, 2011)

GBR in WA said:


> Without an insulated door/hatch at the top of the stairs, you need to insulate the stair walls, floor, risers/treads, and door since they are coupled to the interior conditioned spaces. You have an effective stairwell heat-sink there... the reason it is warm when you step inside the well. You have no thermal boundary established, air-seal the attic first; http://oee.nrcan.gc.ca/publications/residential/9373
> 
> Gary


+1

I didn't see one but I didn't even think to recommend that. Thought it would have been a standard.


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