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Is it possible to resurface an exposed aggregate concrete patio? My current patio surface is about 20 years old, and the aggregate has deteriorated a bit and is pretty ugly looking and painful to walk on. Here's a picture:

http://i.imgur.com/xgNSNgS.jpg enter image description here

Resurfacing seems like a good solution, but I'm unsure of how well an overlay would bond to the aggregate stone. Is there a product that might work?

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If you don't have to make the overlay "very thin" and the patio is structurally sound, there's not a whole lot of "bonding" needed - a 1-1/2 - 2" thick overlay on a sound, solid concrete substrate will happily sit there, unless it has voids to encourage spalling (by filling with water and freezing) in the winter. As it happens, that looks like a pretty good bet for bonding to (with very exposed aggregate) though it would probably be advisable to pressure-wash it to remove any loose material, and probably also acid-etch it to improve bonding and further clean it up.

Thin is generally harder to do well with masonry materials.

  • You could also grind the area the amount of grinding can be controlled and make the top of the surface smother. You don't want a slick surface, I have done this with a 9" angle grinder with water and diamond cutters that made a old salt and pepper exposed job look better than new. – Ed Beal May 14 '16 at 19:21
  • @EdBeal Thanks for the idea. I looked at some pictures of ground exposed aggregate, and I don't think it's my cup of tea. Plus some of this exposed stuff is VERY exposed and would require a lot of grinding, in addition to there being missing pebbles here and there. A nice clean topcoat would be preferable. – Jonathan May 15 '16 at 0:13
  • @Ecnerwal Thanks for the info. The overlay products I looked at like Mapei and Sakrete (which has bad reviews) mention doing 1/8" max layers. How would I get to a 1-2" thick overlay? Any particular product/system I should look at? Also, aside from pressure washing, any other prep needed that might help like a primer or acid wash (maybe this varies by system)? – Jonathan May 15 '16 at 0:16
  • I'm basically looking at "pour a thin slab on top of the one you have" where "Thin" is 1-1/2" or so, involving 3/4" minus or 5/8" minus aggregates - if the extra height does not upset anything else about your patio, it gets you back to the realm or normal concrete practices. The "very thin overlay" products you are looking at are a different deal, and ideal for things like resurfacing your basement floor, when another inch could cause problems. – Ecnerwal May 18 '16 at 1:18
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you must first grind the pea gravel down to get a "level" surface. Clean thoroghly and let dry. apply bonding agent and let cure as per directions. Resurface with several thin coats or use a stampable overlay mix, about 3/8 to 1/2 inch. I recommend Butterfield T1000 Stampable Overlay. It can be integral colored or stained as you like. Then seal it up. Mission accomplished! It may be necessary to rent a scarifier and use it first, then a grinder/polisher to even it up to a level surface. Use a gauge rake or squeegee to lay the product or make one yourself. Good Luck! John Russell, CreteTechnique, Huntsville, AL

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