Correct method for gunite crack repair?

BB_Sacramento

Well-known member
Aug 14, 2015
80
sacramento/CA
We are getting bids for having our inground gunite pool replastered and we have several long cracks in the plaster. Last summer we had a leak company determine that one crack below the skimmer basket was leaking. We patched all the cracks at the time with A+B putty and the leaking stopped. The replaster companies aren't sure how bad the cracks are but think the gunite is cracked below the plaster. I guess they don't know how bad it is until the plaster is removed? One company said they have the gunite removed down to the dirt at the cracks, (long trenches removed) then rebar and new gunite is filled in before new plaster is applied. Another company said they have someone come fill in the cracks with some kind of adhesive. I spoke with that person who told me their method is superior to cutting a trench in the gunite. I'm not sure which method is better/more permanent. Any advice?
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
26,487
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
You get the opinion of a structural engineer on the root cause of the cracking and fix. What is the best fix technique can only be determined after the plaster is removed and the cracks in the gunite shell are examined.

Being in CA you are in earthquake country and the ground may be moving causing the cracks.

You may need concrete staples with epoxy injection for a mechanical solid fix. This is a common concrete repair technique.

Watch


Torque Lock

Concrete Crack Repair Staples for Swimming Pools and Pool Decks | AquaStitch

Pool Structural Repair Staples. Carbon Fiber Kevlar Repair by Fortress Stabilization
 

BB_Sacramento

Well-known member
Aug 14, 2015
80
sacramento/CA
The person I spoke to regarding the epoxy fill told me that he has to perform the fill BEFORE the plaster is removed because once the plaster is removed some pieces will get into the crack and make the crack dirty.
That is an interesting/educational video - thanks for sharing.
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
26,487
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
The person I spoke to regarding the epoxy fill told me that he has to perform the fill BEFORE the plaster is removed because once the plaster is removed some pieces will get into the crack and make the crack dirty.

I would talk with these folks about what the proper process is if you go with epoxy.


Epoxy may fill the crack and stop the leak but not structurally stop the crack from reappearing.
 
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BB_Sacramento

Well-known member
Aug 14, 2015
80
sacramento/CA
Have you heard of a pool re-plaster company repairing cracks by cutting a trench through the gunite to the soil and putting in new rebar and gunite in the trench? If that is a method, would the new gunite adhere to the old or would there then be cracks on both sides of the trench?
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
26,487
Northern NJ
Pool Size
35000
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Have you heard of a pool re-plaster company repairing cracks by cutting a trench through the gunite to the soil and putting in new rebar and gunite in the trench? If that is a method, would the new gunite adhere to the old or would there then be cracks on both sides of the trench?

The new rebar needs to be epoxied into the old gunite to form the structural foundation for the new gunite. I think the old gunite needs to be prepared with the proper bonding coat. I can imagine it is doable if the contractor knows what he is doing.
 
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JamesW

TFP Expert
Mar 2, 2011
25,954
In my opinion, if the earth is shifting, there's no fix that's going to do much good.

If the original solid concrete didn't hold, a patch won't hold either.

If the crack is going to open, it's going to open regardless of the patch.

Unless you stabilize the earth to prevent settling, it's probably a waste of time doing anything more than just covering the crack.

Epoxy injection might help some and it might be worthwhile as long as it's done correctly and doesn't cost too much.
 
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