My uncle told me to use a 2x4 screed on a big garage floor and I should have listened
He's been finishing for 30 years and said a magnesium screed would be too light for the 30 foot pull on that 6 inch slab. I thought my mag would be fine and went with it last Tuesday. Halfway across, it started to dip and I ended up with a solid inch of low spot I had to fix. It cost me an extra 90 minutes and a lot of extra concrete. Do you guys always switch tools based on the pour size, or do you think a good finisher can make anything work with enough skill?
Tell you what, that exact thing happened to me on a basement slab last fall. Tried to use my 8-foot mag screed on a 20-foot wide pour because I was lazy and didn't want to go get the heavier one. Ended up with a belly in the middle that took forever to float out. @troy_ross is dead on, starting wrong just makes the whole day a fight. Your uncle gave you the golden ticket, those old guys have messed up every way possible so we don't have to. Now I just grab the 2x4 for anything over 15 feet, no questions.
Yeah, that's the exact lesson learned the hard way... the right tool just takes the fight out of the job. A good finisher can fix a lot, but starting with the wrong screed is like running uphill from the gate. Sometimes listening to the old guys saves your back and your concrete.
Nah, gotta disagree. A good finisher knows their tools. My mag screed has handled 30 foot pulls before, you just need the right touch. Maybe @troy_ross had a cheap one that flexes too much.