Where do you all specify gypsum sheathing used as cladding on exterior walls?
Weve been locating it in Division 9 (although we specify gypsum roof underlayment board in Div 7), but we think it should be in Div 9 where exactly, we dont know because the MasterFormat is silent on this product.
Try 06160 - I also just set up that section over the weekend.
We specify gypsum sheathing in Section 09253 - Gypsum Sheathing Board. I do admit that it is a weird one since it is really not a “finish”.
I have also seen gypsum sheathing specified in Section 06100 - Rough Carpentry.
I agree with David; however, will typically specify the gyp sheathing in 06100 when I have wood framing. Irregardless for whether it is placed in 06100 or in 09260 with the Gypsum Wall Board products, I will include a related section reference pointing to it from the other section.
In MasterFormat 2004 Gypsum Sheathing is at 061643 with the other sheathing materials. The Explanations for 092900 Gypsum Board state that gypsum sheathing over metal framing may be included. This a reversal of the primary location of gypsum sheathing from 1995 but retains the option of either location as was the case in 1995.
99% of all of our use of Gypsum Sheathing (on walls) is in metal stud wall construction. Its not a finish product, so for me putting it in 9 has always seemed counter intuitive. Its not got anything to do with wood and is not a wood product, and in our use there is nothing related to Division 6 in its application.
I put it in the metal stud section which I treat as an assembly and performance specification. In the DC and Baltimore area, when it is used in conjunction with metal studs, I have seen a lot of specifications that way. When I have looked at office masters from structural engineers that I have wored with over the years from DC area, Baltimore, and from the Dallas Texas area, every one of them has put it in their metal stud section.
We have never had a question related to ‘where is it’.
Gypsum roof deck sheathing, I put that in Division 7 in my ‘Basic Roofing Materials and Methods’ section and with good reason there too - many manufacturer’s require the use of a specific type of gypsum product.
We have done a very few wood frame projects (that 1%), and there, I put it in the rough carpentry section.
William
I’m with William, think Work Results…
We put the exterior gyp-sheathing in our light gauge steel framing section or rough carpentry based on frame type. We also put roofing underlayment in the Div 07 section where it is required.
I (and our structural engineers) put exterior gyp sheathing in 05400 with the light gage framing. We consider the section analogous to 06100 – and provide the framing and sheathing in one section. I’ve been doing this for years, and it hasn’t been a bid problem here; and then its not dependent on any of the 4 different types of exterior cladding (stone, tile, metal panels, etc.) that we might use on any one building. I do carry the air/water barrier in a Division 7 section, but I think the sheathing is best handled at the time of framing.
As a general rule, since gypsum sheathing is a gypsum board product, we include it in Div. 9 in the gypsum board section and cross-reference it with the “Related Sections”. Sometimes we may include it in the Lath & Plaster section when using it with exterior plaster/stucco. In any event, it always occurs in Div. 9 because the gypsum board supplier may never see it in Div. 5 or 6.
Another related issue is the use of building paper vs. “Tyvek” as a vapor barrier over the sheathing.
California Building Code requires 2 layers of Type D paper over the sheathing. Has anyone had any luck in convincing them about using “Tyvek” or a similar product instead?
Suppliers reading specs? Your joking, right?
Around here, they’re lucky to ever SEE them, much less read them.
Any comments on the new BPB GlasRoc sheathing?
Could one not make a strong case for specifying gypsum sheathing in Division 7, in its own section?
It isn’t metal, wood, plastic or a finish, so it doesn’t naturally fall into Divisions 5, 6 or 9, except as an “accessory,” which it really isn’t. It has a different function - enclosure and weather protection - unrelated to framing.
Since that is its purpose, however, it IS weather-resistant - whether it is conventional or glass-faced - and is often sealed or taped to further enhance its weather resistance. That places it squarely in Division 7. And sheathing isn’t necessarily always gypsum-based - there are foil-faced fiberboard, foam and cementious sheathings, even though those may seldom appear in commercial construction. So, all weather-resistant and insulating sheathings should go in Division 7.
Even plywood, OSB, wood fiberboard and other products that are thought of more as wood products than water-resistant materials and so might seem to belong in Division 6, should go in 7 instead. We put metal and wood siding in Division 7, not 5 or 6. Sheathing should go there too.
It seems so clear. Why were it not always thus?
Who wants to hear that gypsum sheathing is slated for–
06 16 43
Looks like a birthdate to me (perhaps because I’m about half a month older…).
Think system not product?
I relate it to gypsum board and specify it in Section 09253 - Gypsum Sheathing. I suppose it could be part of the exterior finish system. But I think that is more confusing than having it be a “narrowscope” section under 09250 - Gypsum Board.
Hmmm, Shelby, I’m about 2 months younger - that was a good year!
There are many rationales for putting any specific product in a number of places. And there is nothing wrong with that. Its what part of a system a component is, or how it is work related that makes the most logical grouping for any given item.
Now, if a master title that was ‘SHEATHING’ for all types of sheathing (cement composite board, gypsum, plywood, insulation sheathing, etc.) then it might make sense to see a single area for these. Curiously, I personally think that ends up being a division 7 series of sections rather than anything else.
I say curiously, which means curious to me for that is not a location where I have ever specified any sheathing.
Mostly my own practice has involved different kinds of sheathing, but only one type at a time. And I put it in as part of the wall framing system, so it ends up in 5 or 6 depensing on the framing type.
My personal least favorite place for it would be 9. Sure, gypsum sheathing is a gypsum product. But most metal coating systems (05080) are paints and they go in 5, not 9, and they are sure more of a finish and related more directly to paints than gypsum sheathing is to interior drywall.
And, regardless of where anyone places it, likely no one has had a question from the contractor asking “where is the sheathing specified.” So, its best placed where it makes the most logical sense to you.
And if you ever do get a question from a contractor about where any item is specified, unless its in the ‘dumb question category’ related to simply not looking in the project manual at all, then likely that would be a good indication that it just might be in the wrong place and you need examine your logic.
Otherwise, its like the rose, which by any other name (or location), its still a rose.
William
Lynn/Shelby-- I wish I could remember what a good year '43 was!! But being about as old as dirt, I leave the evaluation to you youngsters.
But seriously, am I remiss in this, but the new CSI numbering system has Gypsum Sheathing slated as I noted? Guess they see it more in the context of work to be done, rather than a product of certain content [I know I’ll get “bombed” (a '43 term) for that view]
William (and others) - As of the 11/03 update MasterSpec now offers a Section 06060 - Sheathing. About the only thing not included are the cementitious backer unit products.
Oops - Section 06160.