Building Science Corp.

[Raymond Wand]

In what is turning out to be an unfortunate turn of phrase the terms “unvented attics” and “unvented roofs” have entered the lexicon. A lot of the blame for that goes to me and for that I am sorry. The “right” terms should have been “conditioned attics” and “conditioned roofs”.

When we move insulation to the underside of a roof deck the space below the insulation is now within the “conditioned space”. This has all kinds of implications . . . some good . . . some not so good. Read the entire article at buildingscience.com.

BSI-077: Cool Hand Luke Meets Attics ? Building Science Information (http://www.buildingscience.com/documents/insights/bsi-077-cool-hand-luke-meets-attics#P01)

[Ray Thornburg]

I have seen moisture problems in some attics where the roof deck was insulated instead of the attic floor. Especially if there is an air handler located in the attic.....any condensate problems and a lot of excess moisture will be introduced.....with no way out.... In my opinion it is always best to allow for a natural system so that building cavities can dry out. I remember a story recently where they couldn't keep water out of a 12 million dollar space suit. If NASA can't do it I wouldn't expect my local contractor to understand how to keep moisture out of an attic if it isn't vented.

[Jerry Peck]

I remember a story recently where they couldn't keep water out of a 12 million dollar space suit. If NASA can't do it I wouldn't expect my local contractor to understand how to keep moisture out of an attic if it isn't vented.

Ray,

You are comparing a totally sealed space suit to a not-totally sealed house attic?

Really?

I would say that there is no comparison, but ... there can always be a comparison - and the comparison shows that there are no similarities between the two items being compared.

[Ray Thornburg]

Ray,

You are comparing a totally sealed space suit to a not-totally sealed house attic?

Really?

I would say that there is no comparison, but ... there can always be a comparison - and the comparison shows that there are no similarities between the two items being compared.

Thanks for the laugh Jerry.......