| Author |
Message |
Robert E. Woodburn
Senior Member
Username: bwoodburn
Post Number: 146
Registered: 01-2005
| | Posted on Thursday, November 30, 2006 - 06:47 pm: |    |
I'm looking for an epoxy floor coating that is not "vapor-sensitive," for use on the slab-on-grade of a large metal building warehouse to be built in arid far west Texas on dry sandy soil. The project will be built without an underslab vapor retarder for three reasons:
- The soils engineer says an underslab vapor retarder is not necessary and is customarily not used in that area due to climate and soil moisture conditions.
- The PCA says a vapor retarder is not required if the project does not have a "vapor-sensitive covering" or a "humidity controlled area."
- To save money.
The building will be ventilated, but not air-condioned or heated. However, the Owner requires a two-component epoxy coating floor finish. So I need an epoxy floor coating that is not "vapor-sensitive." A search of 4Specs for "epoxy" and "coating" turns up 124 hits, but I don't want to look at all 124 to see how "vapor-sensitive" they are.
Does anyone know of an epoxy system that is sufficiently "vapor-insensitive" to work in this situation? Thanks! |
Anne Whitacre, FCSI CCS
Senior Member
Username: awhitacre
Post Number: 416
Registered: 07-2002
| | Posted on Thursday, November 30, 2006 - 07:02 pm: | |
is there some reason you're tied to epoxy? some of the urethanes might be a little more forgiving in that condition. And if you really do need epoxy, in order to select the floor you'll need to know what its supposed to do -- resist chemicals? resist abrasion? look nice? resist battery acid?
we use epoxy floors regularly in animal lab areas and they all are extremely dependent on having a good vapor barrier, and a waterbarrier under them. The epoxy usually is formulated to keep moisture (or other stuff) from getting to the concrete, which also means that it will trap any moisture in the concrete that is already there. most of the flooring guys can show you really ... alarming photos of epoxies that have trapped vapors under them. |
Robert E. Woodburn
Senior Member
Username: bwoodburn
Post Number: 147
Registered: 01-2005
| | Posted on Friday, December 01, 2006 - 08:24 am: | |
Thanks, Anne. Two-part epoxy is a specific requirement of the Owner's D-B RFP. (Government job...) Quite a few motor vehicles will probably be stored, among other things, on a long-term basis. Not sure what the primary reason is for using epoxy instead of something else. |
Anne Whitacre, FCSI CCS
Senior Member
Username: awhitacre
Post Number: 417
Registered: 07-2002
| | Posted on Friday, December 01, 2006 - 01:55 pm: | |
the ones we seem to use the most are the following three manufacturers. you will need to talk with their reps specifically about recommended systems, and mention that you're not putting in a below slab vapor retarder -- they will need to accomodate that condition.
Selby-Ucrete
Stonhard
Crossfield products
on our projects, Stonhard seems to be a little more competitive but we do regularly specify their equivalent products against each other.
One condition with resinous floors is you will need to let them know what the loading will be, especially if its rolling loads. the one failure we had was with a floor that was installed slightly softer than was standard, and then hard steel wheels (on lab carts) going over it -- the friction ripped up the floor. in general, the floor needs to be harder (less resilient) than the things rolling over it. |
Richard L Matteo, AIA, CSI, CCS
Senior Member
Username: rlmat
Post Number: 183
Registered: 10-2003
| | Posted on Monday, December 04, 2006 - 04:39 pm: | |
I received this info from one of my floor coating manufacturers:
"In general most urethane floor coatings will handle up to 3.0 – 3.5 lbs of moisture vapor transmission, epoxies can handle up to 4.0 – 6.0 lbs.
If a high perm rated coating is required, then it would be an acrylic. However, this type of product will not hold up to heavy traffic, chemicals, etc………in other words, you can’t have both."
I hope this helps. |
Phil Kabza
Senior Member
Username: phil_kabza
Post Number: 222
Registered: 12-2002
| | Posted on Tuesday, December 05, 2006 - 10:18 pm: | |
Urethanes will cope with fuel and oil issues better than epoxies. Slab prep to allow adequate "bite" for the epoxy primer (used in both epoxy and urethane systems) is important.
Why is a structural engineer being allowed to dictate the moisture control issues of a building envelope? Since when is building moisture control part of their practice? Are they insured for this? Why don't they then take responsibility for specifying the floor finish that is affected by their limited understanding of vapor dynamics? After all, it's attached to "their" slab ... |
Mark Gilligan SE, CSI
Senior Member
Username: markgilligan
Post Number: 116
Registered: 05-2005
| | Posted on Wednesday, December 06, 2006 - 02:13 am: | |
When I read the previous postings I found a reference to a soils engineer. I did not find a reference to a structural engineer. |
j smith
Senior Member
Username: specbuster
Post Number: 21
Registered: 07-2003
| | Posted on Wednesday, December 06, 2006 - 10:03 am: | |
I would suggest surface polishing to achieve a sharp look. If you are concerned about vapor drive you need to look elseware ....NO epoxies or urethanes... |
4specs.com Home Page