Sidewalk was overly salted, can I re-pour it there?

[spookycat2]

We had emergency help called several times this winter when Dad was having issues, the sidewalk was slick and so the crews put down salt (heavily) and now it is breaking up so bad it's like gravel now. Mom is concerned that so much salt is on or around the sidewalk that it may affect pouring fresh concrete lasting very long. I know very little about this, does anyone have any ideas?

 

[GoodEnuff]

The little I know is that certain ice melt chemicals will do exactly what you describe on "low quality" concrete. Supposedly, certain types of concrete will not react as badly as that. Can you get a concrete contractor out for an estimate and advice?

An alternative would be to build a sidewalk out of pressure treated wood, similar to a deck, over the damaged sidewalk. Much less expensive and you can more easily place a hand rail on both sides. This would depend on your particular property, HOA, etc.

 

[hollydolly]

We had emergency help called several times this winter when Dad was having issues, the sidewalk was slick and so the crews put down salt (heavily) and now it is breaking up so bad it's like gravel now. Mom is concerned that so much salt is on or around the sidewalk that it may affect pouring fresh concrete lasting very long. I know very little about this, does anyone have any ideas?

I put your question to chat GPT this was the reply


... the good news is that this situation is very common and manageable if handled correctly.

What the salt actually did​

The heavy use of de-icing salt (typically sodium chloride or calcium chloride) likely:

• Damaged the surface of the existing concrete, causing it to flake and break apart (called scaling)
• Left salt residue in the top layer of soil and old concrete debris nearby

That’s why it now looks like loose gravel.

Will it affect new concrete?​

It can—but only if the area isn’t properly prepared.


Salt contamination may:

• Interfere with proper curing/bonding if left in place
• Increase the risk of future surface damage if it remains in the base

The key: proper prep before pouring​

A contractor (or DIY job) should focus on:

1. Remove all damaged material​

• Break up and completely remove the old, salt-damaged concrete
• Don’t pour over it or reuse contaminated chunks as base fill

2. Excavate and replace the base layer​

• Remove a few inches of the underlying soil/gravel if it’s been heavily exposed to salt
• Replace with clean, compacted gravel (road base)

3. Rinse the area​

• Flush the exposed subgrade with water to help wash away residual salts
• Let it drain/dry properly before continuing

4. Use proper concrete mix​

• Ask for air-entrained concrete (this is standard in cold climates)
• Designed to resist freeze–thaw cycles and salt exposure

5. Seal the new concrete​

• After curing, apply a concrete sealer to protect against future salt damage

Extra tip​

If emergency crews needed frequent access, consider:

• Adding a slightly thicker slab
• Improving drainage/slope so water doesn’t sit and freeze

---

 

[hollydolly]

Bottom line​

Salt damage won’t ruin a new sidewalk as long as the old contaminated material is removed and the base is properly rebuilt. This is routine work for experienced concrete contractors.

 

[robin416]

The little I know is that certain ice melt chemicals will do exactly what you describe on "low quality" concrete. Supposedly, certain types of concrete will not react as badly as that. Can you get a concrete contractor out for an estimate and advice?

An alternative would be to build a sidewalk out of pressure treated wood, similar to a deck, over the damaged sidewalk. Much less expensive and you can more easily place a hand rail on both sides. This would depend on your particular property, HOA, etc.

Wood would be much more dangerous in freezing temps. Ask me how I know.

Never mind, I'll tell you. I lived on a boat for a time in a place that would freeze. I'm here to tell you the boat deck and dock were skating rinks. And the back porch and walk at the back of my house? Yeah skippy, get ready for slip and slide.

 

[spookycat2]

Wood would be much more dangerous in freezing temps. Ask me how I know.

Never mind, I'll tell you. I lived on a boat for a time in a place that would freeze. I'm here to tell you the boat deck and dock were skating rinks. And the back porch and walk at the back of my house? Yeah skippy, get ready for slip and slide.

I know exactly what you mean. Back in '08 we moved into Grandma's house after she went to the nursing home. She had a wooden walkway built to bring groceries, etc. in on a cart. Everyone who ever was there in the winter knows by experience!