THERMAL AND AIR BARRIER WALL SYSTEM

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Author Message Richard Hird (Unregistered Guest) Unregistered guest Posted on Saturday, March 05, 2011 - 10:32 am:    Just noticed a DOW Guide specifiction that uses the Section number "07 42 65" for Thermal and Air Barrier Wall Systems. I find this odd; why not 07 25 00 WEATHER BARRIERS which is listed in MF04? Am I missing something in my interpretation of MF04 WEATHER BARRIERS or does Dow know some future change? Dennis C. Elrod, AIA Senior Member Username: delrodtn Post Number: 25 Registered: 04-2010 Posted on Saturday, March 05, 2011 - 11:36 am:    As I continue to update our Ofice Masters to MF04 and fill in needed sections that were never completed, I am finding many instances where manufacturers place their data in a section that doesn't align with my understanding of the MF04 system. I haven't decided if it is bourne out of their lack of understanding of the system, or willful intention to try and set their products apart from the competition. I vascillate between the two. On their behalf, the new system has thrown manufacturers into the gamut of re-tooling their data, and is most cases, maintaining a dual system. It is ultimately the seasoned spec writer's responsibility to determine the appropriate location. I know from my own experience, it creates confusion and I tend to dwell longer than I would like researching and making the final determoination. that part is unfortunate, but as I grow in this new role, I expect I will gain speed with experience. In the end, I agree with you and would relocate it to 07 25 00 :-) Dennis C. Elrod, AIA (Unregistered Guest) Unregistered guest Posted on Saturday, March 05, 2011 - 11:53 am:    I just posted something on another thread that is somewhat germaine. I have found it helpful to remind myself that MasterFormat is about "work products" not "products." Stone may be used as masonry (Division 04), paving (Division 32), tile (Division 09), or toilet partitions (Division 10). As we move toward more sophisticated envelope systems, we are moving from a systems that includes "dampproofing" (which may or may not be an effective weather barrier) to "weather barriers" (to keep weather out) to "thermal and air barier systems" which work to retard the transmission of air or thermal energy from the outside of the envelope to the inside and from inside of the envelope to the outside. A "dampproofing" product may be an effective component of a thermal and air barrier asembly, but used in this way it should no longer be specified as "dampproofing." There have been a number of instances when thinking about "work results" has clarified where something should be specified, at least in my mind. Anne Whitacre, FCSI CCS Senior Member Username: awhitacre Post Number: 1124 Registered: 07-2002 Posted on Sunday, March 06, 2011 - 10:13 pm:    a weather barrier is not necessarily an air barrier, and vice-versa. the two types of products are very different, and have different testing requirements. Tom Good, architect, CDT, SCIP, LEED AP Senior Member Username: tom_good Post Number: 22 Registered: 11-2006 Posted on Monday, March 07, 2011 - 10:28 am:    HUH? I thought Weather Barriers were the gerneal class that included air barriers and vapor retarders. So does MF2004/2010 at 07 25 00 WEATHERBARRIERS. Anne, how are you seeing these as different? I would be interested in knowing to shed more light here. Scott Mize Senior Member Username: scott_mize_ccs_csi Post Number: 45 Registered: 02-2009 Posted on Monday, March 07, 2011 - 10:34 am:    Isn't this one of those "general vs. specific" questions? In other words, a "weather barrier" can be a lot of different things, but "water-resistive", "vapor retarder" and "air barrier" more precisely define its' properties (and intent). And, as Anne noted, those three categories have very different test standards and performance requirements... J. Peter Jordan (Unregistered Guest) Unregistered guest Posted on Monday, March 07, 2011 - 10:43 am:    I am "Unregistered Guest" above. Air barrier systems must resist the passage of air from inside the building to outside as well as from outside the building in. This means that sheet applied products (like 2 courses of No. 15 building paper) can almost never be installed to meet air barrier requirements (including field testing requirements). Wayne Yancey Senior Member Username: wayne_yancey Post Number: 433 Registered: 01-2008 Posted on Monday, March 07, 2011 - 11:13 am:    Dow Building Solutions has created a new section for their innovation exterior thermal insulation and air barrier system using their Thermax rigid polyiso on the exterior (water-resistive barrier with therml properties) supplemented by their SPF in the interior side (the air barrier with thermal properties). All called the THERMAX Wall System, a three-in-one continuous insulation system for steel stud framed buildings - enabling energy-efficient, air and moisture mananaged walls with fewer materials and installation steps. Consult your local AHJ for approval for Construction Types I and II for use of foam plastic insulations in exterior walls. In the recent past (2009), Seattle would not approve this exterior assembly for certain IBC construction types, any height/area but they may have changed their stance. Most case studies that I saw were 1 - 3 stories. Anne Whitacre, FCSI CCS Senior Member Username: awhitacre Post Number: 1126 Registered: 07-2002 Posted on Tuesday, March 08, 2011 - 09:27 pm:    and not to belabor the point (air barrier, weather barrier, etc) it is very possible to have a vapor barrier where there is no "weather" -- say, around a steam room in a gym. Its also useful to have an air barrier as part of your construction in a Clean room with positive pressure. In both of these conditions, there isn't any actual "weather" involved. I think "weather barriers" is the wrong inclusive term, but I'm never going to win that one. Richard HIrd (Unregistered Guest) Unregistered guest Posted on Wednesday, March 09, 2011 - 08:20 am:    Ann: I do not know why you think you lost the argument? Weather barriers begin 07 25 __; Vapor Barriers 07 26 __and Air Barriers 07 27 __, so the latter two are not a subcategory of 07 25; What I do know is what someone invisioned by including 07 25 __. There are no hints. Hope no one tries to come up with one though. It suits my purpose for products designed to meet multiple Thermal Protection goals. Tom Good, architect, CDT, SCIP, LEED AP Senior Member Username: tom_good Post Number: 24 Registered: 11-2006 Posted on Wednesday, March 09, 2011 - 09:28 am:    Richard and Anne, that is a very interesting point Richard. In my post alluding to 07 25 00 Weatherbarriers as a general term for both Vapor Retarders and Air Barriers, I was basing it on my reading of Masterformat 2004 which shows Vapor Retarders and Air Barriers as indented under Weatherbarriers. That is, Weatherbarriers is formatted exactly the same as all the other level 2 Sections and Vapor Retarders and Air Barriers are formatted like all the other level 3 Sections. I didn’t bother reading the numbers! But I see that Richard is correct, all three are level 2 Sections. Masterformat 2010 makes this change in formatting. BUT WAIT, MasterFormat.com, still lists Vapor Retarders and Air Barriers UNDER Weatherbarriers. MasterFormat.com also indicates that 07 25 00 Weatherbarriers includes “materials applied separately in wall, roof, and floor assemblies to resist vapor penetration, primarily to mitigate the consequences of thermal variation. materials installed at walls, roof-wall connections, perimeter of door and window openings, and similar locations to provide a continuous, impermeable barrier to air infiltration or loss.” Argh…. Robert W. Johnson Senior Member Username: robert_w_johnson Post Number: 139 Registered: 03-2009 Posted on Wednesday, March 09, 2011 - 12:05 pm:    After contacting CSI staff, I confirmed that the change in status of 07 25 00 Weather Barriers was a formatting error in the 2010 book printing. 07 25 00 is still intended to include 07 26 00 and 07 27 00 under it as it was in the 2004 edition. The 2011 book is at the printers - staff is trying to get this error corrected for the 2011 book. Tom Good, architect, CDT, SCIP, LEED AP Senior Member Username: tom_good Post Number: 25 Registered: 11-2006 Posted on Wednesday, March 09, 2011 - 01:04 pm:    Robert, if that is so, why are Vapor Retarders and Air Barriers not given level 3 numbers? That is, how can level 2 numbers be UNDER another level 2 number? Are there other places in MasterFormat where this happens? Robert W. Johnson Senior Member Username: robert_w_johnson Post Number: 140 Registered: 03-2009 Posted on Wednesday, March 09, 2011 - 01:23 pm:    Yes there are a few locations where XX X5 00 is used as a Level 2 number to group other Level 2 numbers. Quote from Introduction and Applications Guide: "Some Level 2 numbers in MasterFormat 2004 are used to group related Level 2 subjects so that the organization of the classification is more easily understood and is easier for users to navigate. These Level 2 numbers generally have a zero for the second of the Level 2 pair of numbers (XX X0 00). In a few locations the second of this type of Level 2 pair of numbers is a 5 (XX X5 00). ..... Each of these groups of related subjects then has more detailed Level 2 titles for the various types of (the subject) under them. Although their main purpose is to assist in the organizational structure, these Level 2 numbers and titles may also be used as a Section title in a project manual like any other number and title regardless of level." Tom Good, architect, CDT, SCIP, LEED AP Senior Member Username: tom_good Post Number: 26 Registered: 11-2006 Posted on Thursday, March 10, 2011 - 10:44 am:    Well I now know something new. Thanks for the "explanation" Robert. I will keep it in mind. Personally I do NOT find it "....more easily understood and is easier for users to navigate. ..." to use some Level 2 Sections to group other Level 2 Sections and rely only on the level of indentation indicated in MasterFormat to indicate this grouping. It would be MUCH easiliy understood and navigable to group the numbers NUMERICALLY. But as resistance is futile, I will assimilate. Robert W. Johnson Senior Member Username: robert_w_johnson Post Number: 141 Registered: 03-2009 Posted on Thursday, March 10, 2011 - 11:06 am:    Agreed, it is much easier understood when the grouping title is a XX X0 00 configuration that is used repeatly throughout MasterFormat. A few divisions (7 and 11 are examples) had too many categories to restrict to the XX X0 00 configuration and had to use the XX X5 00 configuration. Could have gone to more digits, but you can imagine how popular that would have been! Not easy to have the perfect system!