Related to my garage door change from quantity 2 9 foot OH doors to one 12' (https://www.garagejournal.com/forum/threads/do-i-need-a-temp-supporting-wall.556886/), I'm planning to overpour concrete on existing apron for the wing wall extensions foundation. I plan to use a concrete bonding liquid (brushed onto existing concrete), but should I etch the old concrete first? There are no oil/grease stains on apron, but I do want to make sure I get a good bond.
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Etch concrete before bonding agent?
- Thread starter MikeC55
- Start date
Rusted Nut
Well-known member
Follow the instructions for the bonding agent you are using.
willymakeit
Well-known member
How thick of a overpour?
I don't like to bond to existing usually as the two slabs can move independently without any transfer.
We put a thin sand layer down when pouring over solid rock for this reason.
I don't like to bond to existing usually as the two slabs can move independently without any transfer.
We put a thin sand layer down when pouring over solid rock for this reason.
Overpour is around 4". I'm also going to have some concrete anchors going up from old contrete, through the new stuff, as (2 x 4 / plywood) wall anchor bolts. I think these should help preventing independent movement. Also, I'm only talking about a pour area for each side of 10" x 6'.
willymakeit
Well-known member
You should be fine
strutaeng
Well-known member
A light griding may be required if it was troweled really smooth, but probably not. Or light chipping to scarify the surface. That's what we specify for structural repairs. Probably not needed here. Bonding agent and call it good.
A few #3 vertical dowels with epoxy (maybe with a #3 continuous horizontal?) is what I would do. This is the little cubs for the walls, right?
A few #3 vertical dowels with epoxy (maybe with a #3 continuous horizontal?) is what I would do. This is the little cubs for the walls, right?