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Next question. This comes from SM. I don't know. I just know the initials
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And he says, I'm trying to find a method to fix small crumbly areas in my concrete driveway
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Well, I'm glad you asked because it's easy to make a mistake here, and you don't know you've made a mistake until you've gone to a lot of trouble, and the patch fails
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And by failing, I mean whatever you add to fill in this crumbly deteriorating area has come loose, broken loose around the edges as a minimum, or just come right out altogether
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It's very disappointing, and you can waste a lot of time. So here's how you do it so it works every time
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First, you want to, this is for concrete driveways too. This is not asphalt
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This is concrete. So it works on sidewalks, garage floors, basement floors, anything like that
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You want to start by removing everything that's loose from the deteriorating area
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And the best way to do that if you're outside is to use a pressure washer, just blasted there
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That's going to remove all the dust very easily and quickly, but it'll also shake loose anything that's kind of about to come off in the deterioration zone
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zone You want a nice clean slate to start with Now concrete is a mixture of sand cement and crushed stone but you don want to use that for this patch because the crushed stone is going to prevent you from smootening things properly where the patched area gets really thin
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around the edges of the deteriorating zone. So what you want to use is mortar, which is quite a bit
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like concrete except that doesn't have the crushed stone. Chances are you're not going to need a
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whole lot of this so you don't need to have a truckload of sand brought in and some bags of cement
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you can buy a ready-to-mix mortar mix. That's what it's called. It comes in a bag
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The cement and the sand are already mixed together, dry, and then you just add liquid to turn it into a mortar
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Now, you could just trowel this mortar in to your damaged area
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but it's not going to work. It's not going to hold. And there's two things you need to do to make sure that the repair lasts well
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The first thing is to use something called liquid bonding agent. agent both in the patched area and as part of the liquid you add to the powder to make the mortar
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So liquid bonding agent is a white liquid. It looks and has a consistency of milk. It's actually
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a really watered down polyvinyl acetate adhesive. So polyvinyl acetate PVA, that's the
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chemistry that's used for ordinary white glue. So think of it like white glue, except more
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water's been added so it's quite liquid. But you want to use the bonding agent in two ways
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First of all, you want to brush it into the area that you're going to be repairing
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because the bonding agent as you imagine from the name boosts the bond of any additional masonry you add to it So just brush it on maybe a minute or two before you going to be laying in your mortar to smoothen that out
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Give it just enough time to soak in and then have everything else ready and get to work
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Now the second way you use the bonding agent is, as I said, is part of the liquid that's used to turn the powder into mortar
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and maybe one third, one half at the most of the liquid should be bonding agent, the rest is water
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and you want to mix your mortar so it's kind of the consistency of peanut butter or so maybe a little bit softer than peanut butter
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but it should stick. If you make a little pile of it and cut the pile in half, it, you know, it shouldn't slump
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You know, if you've made it cut this deep, it should hold itself together. You don't want it to be runny because that means too much liquid, and that way
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won't make for a strong patch. So that takes care of the bonding side of things, but there's
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another side of the equation too. And that has to do with the fact that all cement products
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so mortar, concrete, whatever, hardens not by drying, but by chemical reaction. And water has to
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be present for that chemical reaction to occur. So it's vitally important after you've laid in
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your bonding agent and you've trowled in your repair mortar and you've smoothed it over and it
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looks nice, don't just walk away because if you do, chances are excellent that the mortar
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will dry out too soon because you know these patches aren very thick you know maybe an inch thick or so typically and then it gets quite a bit thinner at the edges where the depth of decay reduces So in places like that and especially around the edges drying out prematurely is a distinct possibility
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And once it's dried out, as it started to set, it'll never reach its full strength
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And you want it to reach its full strength. So what you do is you have to keep it wet
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I like to keep things like this wet for a couple of days. And it's not enough just to sprinkle water on and go away and, you know
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barbecue some hamburgers and come back and put some more on an hour or two later because there would have been drying that happened
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So ideally what you want to do is you want to wet some cloths, you know, old bed sheets
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piles of old rags, burlap bags, whatever. You want to wet that and put it down on the air
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You can put it right down when the mortar is wet. It doesn't really matter. It might make a few little marks, but it's not significant
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And then keep that fabric wet for a couple of days. And if you do that, you're going to get a really nice repair
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Now, I should say that after a couple of days, that patch is going to seem hard, but it's not fully hard
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So I wouldn't drive on anything that you've patched like this for maybe a week or so
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Because you really want to do everything you can to make sure this thing works
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And if you follow the directions I've just given you, it will work. And you're not going to have any trouble
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The patch is going to hang on
