Garage floor question

[Rob Blaustein]

My wife got me plastic floor tiles (like Racedeck, but their Costco version) for our concrete garage but I'm concerned about moisture. I suspect that the issue is mostly condensation but there may be some water movement from below as well--I'm about to check using the tape test (taping some plastic or alum foil, etc). Has anyone ever put that type of flooring down on a garage that gets wet from time to time? I was also looking into one of these insulating/air gap materials like Dri-core, Platon, or Delta-FL (http://www.deltafl.com/), to put underneath but was a bit concerned about the weight of a car (what, use valuable shop space for a car?!). For example, the Delta-FL has a compressive strength of 5200 lbs/sq ft.--not sure how that would play out with a 3500 lb car over 4 tires etc. But I also don't want to make things too difficult, so if the plastic floor tiles would allow moisture to evaporate, I'd just lay them down and be done with it. Anyone have experience with these?
--Rob

[Rob Blaustein]

For example, the Delta-FL has a compressive strength of 5200 lbs/sq ft.--not sure how that would play out with a 3500 lb car over 4 tires etc.

OK, just figured out this part and it hadn't occurred to me previously. The tire's PSI plus weight of the car gives the contact area. Or looked at another way, the compressive strength of Delta-FL is 36 PSI, right around what the car tire's pressure is, so it is on the edge.

[Brian Tax]

I also had some moisture problems on my garage floor. I painted the floor with one of those epoxy garage floor coatings, rustolium I think. No more moisture problems on the floor. I was able to do it in a weekend, the pain it to get everyting out of the garage and clean and etch the floor first.

[Bas Pluim]

I put those plastic tiles in my basement workshop, over the concrete floor. The basement is fairly damp, so I run a small dehumidifier to help keep things dry. The concrete floor will occasionally get damp when it's real wet outside. During extended rains/ hurricanes, I'll even get some minor flooding.

The tiles haven't caused any problems. Although interlocked, they don't form an impenetrable barrier, i.e. water can evaporate through them. But, the majority of moisture will be removed through the concrete via osmosis. No amount of evaporation would help anyway if the concrete was so wet water would puddle on top of it. Remember, those tiles are made for garages, with people parking cars wet from the rain, hosing out the garage to clean etc.

If you have condensation/ moisture problems today, the tiles certainly won't worsen things and may even improve it a little. But, if the garage floor frequently gets wet, you may need to to look at improving the grading away from the house, sealing the garage floor etc. If you put down tiles , you don't have to worry about making a super pretty epoxy floor with flecks.

I've been very happy with these tiles. They sound a little "hollow" when you walk on them, but you get used to it really quickly. The rubber tiles you can get sound better, but are also 3-5 times as expensive. I've found them to be virtually indestructible (unless you drop a 100lb workbench top on its tip on it) and very easy to clean. Glue, paint, blood, poly, all the usual workshop stuff comes off easily.