Serious question, I always thought a 2x4 screed was fine for everything

I was reading an old trade manual from the 80s I found at a yard sale in Tacoma. It said for a slab over 15 feet, you should use a 2x6 screed to stop it from bowing in the middle. I've been using a 2x4 on 20-foot pours for ten years. I tried the 2x6 on a garage floor last week and the flatness was way better. Has anyone else switched to a thicker screed for bigger jobs?

3 comments

3 Comments

alicehernandez1mo ago

That old manual is onto something. The extra stiffness from a 2x6 just handles the long pull better. Makes a real difference on the bigger slabs.

milesbailey1mo ago

Yeah, that "extra stiffness" point came up in a forum thread I saw.

jenny_hall1mo ago

Oh man, my last DIY project proved I should probably just stick to the manual. I added "extra stiffness" and got a wobbly mess instead.