Attic Ventilation Question 1

[MRM]

Hi everyone,
I'm not sure if this is the right place for this question, but it does have to do with air movement and that sort of thing.

What is the best way to promote good ventilation in an attic? I live in an area that is below freezing in the winter. Last week, I had a look up in the attic. I noticed a substantial amount of frost on the underside of the roof and on the end walls. I have to think that warm, moist air was entering the attic from the living space, running into the cold air in the attic, and condensing as frost. I've sealed up the attic entry hatch (which I think is where air was entering the attic). Perhaps this may have solved the problem-I'm not sure yet.

1. What do I need to do or have in the attic to promote good ventilation so that the air gets exchanged frequently?
2. Has anyone else had this problem, and what did you do about it?
3. Is it possible that the attic entry hatch (if unsealed) could transmit enough warm, moist air to cause the frost that I observed?
Thanks for your opinion!

 

[aviat]

There is some info at this site.

http://www.cmhc-schl.gc.ca/en/burema/gesein/abhose/abhose_ce13.cfm

 

[ercanbaser]

try this;

http://www.askthebuilder.com/Ventilation.shtml

regards,
Ercan BA?ER