Why does everyone forget to wet the base before pouring...

I was on a job in Austin last week and watched a crew dump a whole 6-yard load onto bone dry dirt. The slab cracked before they even finished finishing it. I've been doing this for 12 years and I always hose down the subgrade first, it makes a huge difference. Am I the only one who still does this or has everyone just gotten lazy?

3 comments

3 Comments

davis.noah1mo agoMost Upvoted

@iris_davis90 nailed it about the hydration thing. I started wetting the base a few years back after a similar crack job and it made a huge difference. Plus the concrete flows way easier when the ground isn't sucking all the moisture out.

henry_martinez1mo ago

That's a good point about the crew being in a hurry. I've seen it happen too often where they're trying to beat the clock and skip the basic steps. Wetting the base isn't just about keeping it from cracking, it also helps the concrete flow and settle better. A dry subgrade can suck the moisture right out of the bottom of the slab before it has a chance to cure properly.

iris_davis901mo ago

Honestly, that "dry subgrade sucking the moisture out" is the exact issue I've seen blow up jobs days later. You're right, it's not just about cracking, it's about giving the concrete time to actually hydrate and gain strength properly.