Shoutout to my old foreman Mike for telling me to wet the subgrade before pouring

Been doing flatwork for about 10 years now and always just went in dry, figured the mix had enough water in it. Mike who's been finishing since the 80s told me I was gonna get cracking near the edges every time if I didn't wet down the dirt first. Tried it on a big driveway job out in Maplewood last month and sure enough not a single crack along the perimeter. Has anyone else had a boss yell something at you that ended up being the best advice you ever got?

2 comments

2 Comments

taylorc501mo ago

I get what you're saying but wetting the subgrade isn't always the magic fix people make it out to be. If you oversaturate it you end up with muddy conditions that mess with your slump and then the slab sits uneven. Had that happen on a patio job outside Portland last year, foreman told me to soak it good and we ended up with soft spots that led to settlement cracks anyway. A light misting is fine, but straight up watering it like a garden bed can cause just as many problems as going in dry. Always a trade off with this stuff.

gray_roberts1mo ago

That's exactly the kind of thing that can go sideways fast. Overwatering turns the subgrade into a spongy mess and you lose all the support you thought you had under the slab. A good rule I've heard is to mist it just enough to darken the dirt and then let it sit a few hours before you pour.