Vapor Barrier

[renjaminfrankln]

Hi,

In researching posts about garage floor coatings, I have seen that an epoxy floor coating does not work on a slab with no vapor barrier (I assume plastic that is set down before the concrete is poured).

The house that I am currently under contract to buy was built in 1987, attached 2 car garage with concrete floor in very good shape (smooth, no big cracks, pits etc). Appears the contractor did a nice job on the house as well

Can I assume this does have a vapor barrier? Should I try and find out somehow?

 

[CombatNinja]

First, it is not impossible to get a proper result from epoxy with no vapor barrier. Plenty here have done it. You just need to prepare properly and apply the right products. I'm sure one of the flooring reps will chime in here, but it can be done.

Second, the best way to assess your moisture situation is to get a few pieces of nice thick plastic and duct tape them down on different sections of the floor. Check them after 96 hours or so. If you have condensation under there, then obviously moisture is coming up through your slab. Do this during a period of wet weather, obviously.

 

[Armorpoxy]

Agree. using the plastic sheet method is a good place to start. To elaborate on above we recommend using 4' square clear plastic in the center of the floor. Tape down well with duct tape all four sides. Wait 24 hours. If dampening, or worse, condensation appears, then you would need to test with a moisture test kit (we sell these, they are like radon test kits) and if the level is higher than about 4 lbs/1000 sq ft/24 hours, a moisture barrier epoxy primer would be recommended.

 

[LegacyIndustrial]

Keep in mind that Moisture Vapor Barriers, Like our AquaDike, are only as good as your preparation. These products require diamond grinding at a minimum.

 

[Armorpoxy]

Legacy 100% correct, and to add to that Moisture Barrier epoxies go on 3x thicker than standard epoxy primer so you need much more material, and the material costs about 40% more so this step can run as much as the entire epoxy system, plus the extra prep involved.