Need some advice on a subject that we cannot agree on in the office.
When specifying vapor control treatment of a concrete slab on grade, does the Section belong in Division 03, 07 or 09?
I use 09 6116 “Vapor Control Floor Treatment” because the application typically relates to preparation for floor coverings. This was derived from MasterFormat Section 09 6100 “Flooring Treatment” which is intended for “coatings & surfacings for finished flooring, applied to provide a specific performance characteristic.”
Are you talking about under-slab plastic sheet products or products applied to the exposed slab surface after it has cured?
We work with the structural engineer specs and place it in Division 03. Our experience has been that the Contractor can miss it if it is not with the slab pour information.
also note that in CA that CALGREEN is helping us get the vapor control in the right place, directly under the slab - no sand between, no place for water to hide for expusion at a later date and cause flooring issues. Contractors will fight this, but fight back and fight on.
Like Julie, we include the Under-Slab vapor retarder as an Article in the Division 03 Concrete section. If youre talking about a surface treatment “On Top” of the concrete slab in preparation for flooring then Id agree with Jeffrey and put that in Division 09
Gerard, we had a joint presentation last year - local CSI chapter with Flooring Council - on the whole vapor drive issue. One intriguing suggestion that came out of the discussion after the presentation was a Division 09 Common Work Results for flooring, that would deal with slab moisture testing and with topical treatments. The common work results idea keeps you from repeating the testing in a half dozen different flooring sections. The conscensus was that integral treatments in the concrete belong in Div 03.
We’ve recently had this discussion here. We prefer to have the structural engineer include vapor barrier under the slab in cast-in-place concrete, but we’ll put it in Division 07 if we have to. We have a new Section 096110-Vapor Mitigation at Slabs, including the cement underlayment, for treatment prior to applying floor finishes. Cementitious underlayment not related to vapor mitigation issues remains in Division 03.
Lisa, is the Owner simply expected to pay for mitigation as part of the base bid or is this something added by change order after the fact? is there an up-front allowance with unit prices for adjustment? Does the Contractor have any responsibility, or incentive, to avoid needing to resort to mitigation? Seems like a blank check.
Regarding testing as a ‘Common Work Result’, I’ve long been an advocate of having an independent agency test for vapor drive (RH and calcium chloride) and pH. Most flooring manufacturers seem to reject that idea and want to control testing; they don’t want to be responsible for installations over surfaces that don’t meet their requirements so they want to test the surfaces anyway. I don’t see any reason why the requirements can’t be in one “Common” Section and referred to by the other Sections but I don’t think the installers will give up control of testing. Has anyone had other experiences?
I recommend that no matter where you decide to show the membrane that you coordinate with the structural drawings and the cast-in-place concrete specification sections. Some engineers normally call out a membrane. The problem is that the membrane that they call out may not be what you want. In addition I suspect some engineers are still calling for the sand layer on top of the membrane.
Some engineers prefer not to show the membrene since it deals with issues related to moisture nd the building envelope which they believe is outside their scope of work. In this context they may be more willing to show the membrane if there is clear documentation that the architect has made the technical decision and that they are only showing what the architect has decided.
We specify the requirements for moisture and pH testing in each individual DIV 09 floor finish Section because the flooring manufacturers often require different testing procedures as well as different allowable test results.
Those individual flooring Sections then refer to the remedial procedure Section for slab vapor control if the tests fail.
For years I had the slab vapor control Section in DIV 07 where it came right after our under slab-on-grade vapor retarder Section because that relationship simply pleased me. But as others have noted, I too have since become enamoured of the “Common Work Results…” concept for many areas of Work and now have it at the beginning of DIV 09.
We review with the structural engineer at outline if they or ourselves will specify the under slab-on-grade vapor retarder. We basically started doing it ourselves when that was the only way to get the quality we wanted.
For the admixture slab vapor control products or “same day as the pour” slab vapor control products, we try to get those into the 03 concrete spec, usually “Cast-in-Place…” unless there is a seperate “Concrete Finishes” Section (We do a lot of big medical and science work and the structural engineers often dump the whole issue of floor flatness and finishing to we Architects, so we put that in there as well).
As for who pays, I prefer there to be an allowance or a unit price in place based on crystal ball gazing or whatever.
I once had a call back where the same piece of floor was failing on every level of a 10 story building. Long story short: That was where the tower crane had been and where they came back quick and dirty late in the job to fill in the slab opening.
Concrete admixtures need to be addressed in the cast-in-place concrete specificaiton section.
Products applied after the concrete is placed may be better located in another specification section although a reference to the related section probably should be located in the CIP section. The CIP concrete section is often a large section which can benefit from spinning off such products into another section when feasible.