DJK555

I just opened a 16X32 in ground Vinyl liner pool that has a concrete coping backed up with concrete pavers forming a deck. The coping was made from coloured concrete and was painted in the past. Last year I did some spot repairs on the coping and repainted the whole thing to match colours. This year, when removing the water bags and winter cover there was a number of areas where the coping had spalled and the new paint had flaked. The flaking paint I can deal with but I am concerned about the spalling/flaking concrete. Any suggestion on how to address this problem will be appreciated.

BridgeMan

The concrete deterioration you're seeing is actually called scaling, not spalling. If the concrete coping is older, but hasn't shown any scaling until after you painted it, I suspect the paint could have possibly triggered the scaling mechanism in the concrete. Not very common, but a definite possibility.

If the concrete coping is reasonably new (less than a year or two), then the chances are good that the scaling was going to happen whether or not the concrete was painted. Scaling is usually caused by over-working the concrete during finishing operations, making the water-cement ratio too high at the surface. Sometimes it can take a year or more to show up.

There are no easy fixes. It will take a lot of work to remove all of the bad (and potentially-bad) stuff before a good coating can be applied. Sand-blasting or hydrodemolition are several removal methods that work well.

DJK555

Thanks Bridgeman.

What is your opinion of the epoxy based concrete resuracing products like Armor Poxy for this type of application? http://www.armorpoxy.com/

BridgeMan

I have no experience with Armorpoxy, or (recent) experience with any epoxy coatings, for that matter. The epoxy coatings I had DOT experience with in the late 1980s, used as "attempted" bridge deck overlays, performed miserably. Several manufacturers' products loosened and came up in large sheets within a few weeks of having been applied, and both applications were done with factory technical reps on hand "to make sure everything was done right."

I suspect a lot of progress has been made in the epoxy surface coating industry in the last 30 year, so you might get lucky. Just make sure your surface prep is up to snuff, getting all loose and potentially loose (delaminated) material removed before you start the application.