Foam gasket solution for clean concrete edges works like a charm

[mirelurker]

Hi everyone,
I'm helping my dad build a new shed on the farm in rural Ohio. He's been doing this for 40yrs and always hated the messy edges. He's tried everything roll roofing, tape, even caulking. Then he found a precut foam gasket made for concrete forms. It goes right into the seam between the form and ground. It stays put and leaves no mark.
Does this type of gasket work well in cold weather pours?
Can it handle high slump concrete without shifting?

 

[PourItRight]

Foam gaskets are great for cold weather concrete. Just be sure to use closed-cell foam that's meant to touch concrete. If the concrete is too wet, it might move the gasket, so make sure it's secure

 

[Brain Drain]

We used that same kind of gasket last winter when we poured a pole barn floor in northern Indiana. It was cold, around 20 F but the gasket worked really well, even with wet concrete. We pressed it in tight and made sure the forms were close together. It didn't move, and the edge looked neat.

 

[mirelurker]

Both replies suggest that closed-cell foam is the way to go, which aligns with what we used. Ours was rated for concrete contact and held up well, even with a 6-inch slab and a slump of about 5. Hearing about @Brain Drain's experience in 20-degree weather is helpful, since we're planning a small pour in late October and it often gets below freezing at night here in Ohio. We'll ensure the forms fit tightly and may warm up the foam if it feels stiff from the cold. Has anyone tried a gasket like this with fiber-reinforced mixes? I'm curious if the extra texture changes how clean the edge looks. We're considering fiber for the next pour to help prevent cracking.