Expert: Bruce E. Johnson - 4/2/2009

Question
can Drywall handle extreme temperature changes. on our Garage with loft i was wondering if we can use Drywall.  the loft will be heated with Wood stove only and used in winter. temperatures from maybe -30 to + 25 in a couple of hours.

Answer
Hi dawn, gypsum materials such as drywall can handle very extreme temperature changes.  For this reason they are used for fire stops and for fireproofing other materials.  USG has a great website where you can download any information regarding types of drywall, specifications, mold resistant, etc.  It is:http://www.usg.com/DocsAndMedia.do?cat=Prod%20Data%20and%20Submittal%20Sheets
copy and past the above link to your browser and it will take you to a list of pdf files you can download.
The biggest foe you will face in your project is moisture.  Lack of heat may allow moisture to build up in the space.  If the space is not used or heated that often then I would suggest a moisture resistant drywall or an exterior grade.  But if the temperatures are below freezing most of the time, moisture will be less of a problem because the air is so dry (the moisture is on the ground).

All in all, drywall is a good product for your loft.  I hope this information helps feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com