I'm pouring a sidewalk slab along the side of my girlfriend's house in Oregon. It's 25 feet long by 4 feet wide and 5 inches thick, with welded wire mesh in the center. The slab will run between the house foundation and a row of concrete pavers. I've done masonry work for years but haven't dealt with this kind of narrow run before. Should I add joints every 5 feet or can I stretch it to 10 without risking cracks?
Sidewalk slab expansion project
- Thread starter Materia43
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gildenhorns23
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- Aug 30, 2025
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Nice work! I poured a 30-foot long, 3-foot wide path last fall in Portland with the same thickness and wire mesh. I put joints every 5 feet, and it's held up great, no cracks so far.
Most tips say to space joints about 2–3 times the slab thickness in inches, so 10 feet might be too far for a 5-inch slab. Oregon's weather can be rough on concrete, so closer joints might help. Are you adding any joints near the house or the pavers?
Most tips say to space joints about 2–3 times the slab thickness in inches, so 10 feet might be too far for a 5-inch slab. Oregon's weather can be rough on concrete, so closer joints might help. Are you adding any joints near the house or the pavers?
TheClock
Active member
@Materia43 a common misconception is that the welded wire mesh will prevent the concrete from cracking.
let me tell you that it won't. The mesh is there to hold the pieces of concrete together after they crack.
The joints are what control where that crack is going to happen. You have a long run, and concrete will shrink as it cures. If you only put joints every 10 feet, you'll get a random crack somewhere in the middle
let me tell you that it won't. The mesh is there to hold the pieces of concrete together after they crack.
The joints are what control where that crack is going to happen. You have a long run, and concrete will shrink as it cures. If you only put joints every 10 feet, you'll get a random crack somewhere in the middle
You both seem to agree, so I'll go with the 5-foot spacing. It's clear that welded wire mesh won't prevent cracks and joints are what really control them. The 2-3x slab thickness rule is what I've used before. Since Oregon has freeze-thaw cycles, I don't want to take any chances. I haven't put in joints near the house or pavers yet but I'll add them once the concrete is firm enough to walk on. I'm planning to pour this weekend and will set the spacing before the weather changes.
