insulation in high-moisture areas

Log Out | Topics | Search Moderators | Register | Edit Profile

Author Message Robin E. Snyder Senior Member Username: robin Post Number: 245 Registered: 08-2004 Posted on Wednesday, March 25, 2009 - 12:00 pm:    Is there any type of insulation that is recommended for high-moisture areas, such as offices and spaces adjacent to a natatorium (not the natatorium itself)? Marc C Chavez Senior Member Username: mchavez Post Number: 339 Registered: 07-2002 Posted on Wednesday, March 25, 2009 - 12:17 pm:    For what it is worth, the Insulfoam folks just gave us a talk and showed an article from a west coast roofing mag that discussed Expanded and Extruded polystyrene foams that had been underground for 15 years. The expanded foam still had absorbed 6% (if I remember correctly) water and retained 90something percent of it’s R value the Extruded board had absorbed 15% moisture and had lost close to 50 % of it’s R value. ...Showing that the ASTM for these materials may not be a true picture of the product. That isn’t your question but I’d talk to the Expanded folks in your area. Curt Norton, CSI, CCS Senior Member Username: curtn Post Number: 141 Registered: 06-2002 Posted on Wednesday, March 25, 2009 - 08:47 pm:    Robin - If are you trying to keep the offices independent of the natatorium environment, you need to treat the wall very much like an exterior wall. You need a proper vapor retarder on the Nat side of the wall and enough insulation in the wall to address dew point. Spray foam insulation is a great choice because if installed thick enough, it has a perm rating of less than 1. However, it is not cheap. An alternative would be to make sure you have a high quality vapor retarder/barrier with continuous insulation on the Nat side, and stop the humidity from moving into the wall. John Bunzick, CCS, CCCA, LEED AP Senior Member Username: bunzick Post Number: 1031 Registered: 03-2002 Posted on Thursday, March 26, 2009 - 01:32 pm:    You need an air barrier around the natatorium envelope as well, at the exterior walls as well as the interior walls. Then the insulation type won't matter because there will be no vapor diffusion, nor air current-borne moisture vapor, to condense within wall assemblies. Robin E. Snyder Senior Member Username: robin Post Number: 246 Registered: 08-2004 Posted on Thursday, March 26, 2009 - 02:34 pm:    i am not looking for a product for the natatorium specifically. I am looking for something that is in the offices and bathroom spaces adjacent to the natatorium and will be getting more of the "residual humidity" Wayne Yancey Senior Member Username: wayne_yancey Post Number: 177 Registered: 01-2008 Posted on Thursday, March 26, 2009 - 02:49 pm:    Robin, Suggested reading. http://www.bdcnetwork.com/article/CA6605050.html John Bunzick, CCS, CCCA, LEED AP Senior Member Username: bunzick Post Number: 1033 Registered: 03-2002 Posted on Thursday, March 26, 2009 - 04:20 pm:    There should be no additional moisture in that location if the wall assembly around the natatorium is properly designed. You want to make sure that there is no (or very little) moisture passing into those spaces from the natatorium. Ron Beard CCS Senior Member Username: rm_beard_ccs Post Number: 299 Registered: 10-2002 Posted on Thursday, March 26, 2009 - 06:57 pm:    <<the insulation type won't matter because there will be no vapor diffusion, nor air current-borne moisture vapor, to condense within wall assemblies>> John, no offense intended, but strong definitive statements scare me. Unless you are providing the CA, the specifier doesn't know the quality of construction. If project conditions warrants the extra QA, I will include strict vapor barrier taping and caulking requirements.... including a statement that the Owner reserves the right to perform door blower testing for air leakage. It has never happened because the installer has been forewarned and usually does the installation correctly. Robin: When dealing with hostile environments [ie, a natatorium], I suggest you review the proposed HVAC systems for both the hostile environment space and any adjacent space. The air pressures and relative humidity levels should be different so it may affect your wall design. Also, the gear in the hostitle environment side should be of such materials as to not be affected by chlorine and other chemicals and, naturally, transmissions of such would be undesirable in the living spaces. John Bunzick, CCS, CCCA, LEED AP Senior Member Username: bunzick Post Number: 1034 Registered: 03-2002 Posted on Thursday, March 26, 2009 - 07:05 pm:    Ron, no offense taken. I agree that the specifier has a limited capacity, if an independent, to influence aspects of design. (Here, as an in-firm specifier, I do have great influence.) I guess my point is that if there is moisture getting into these materials there will probably be other issues or failures, possibly significant. I think that a true air barrier assembly is the only way to avoid these problems. Photos I've seen of projects intended to illustrate the need for air barriers invariably have a few of natatoria, and eww, what a mess they can become--I mean, seriously messy--when they lack an air barrier. Perhaps the best you can do is advise your client of this concern.