Re-plaster / crack fix question

[veraj]

Finally planning to pull the trigger and re-plaster the old in-ground pool. Had few questions:

1) There are some hairline vertical cracks / horizontal as well, and I am expecting may be some crack underneath the plaster that are structural. Contractor cannot say if structure or not without removal plaster. If structural, he mentioned that they don't do staples to fix the crack. Instead he says, they remove the shell near the cracked area (till they hit the dirt), put in new rebar connecting to old shell and shoot gunite. There is a minimum cost to bring in equipment / some minimum material cost to shoot gunite. I am wondering if this is the right approach and has merits over structural staples or has downsides that I need to aware of (and increasing the cost for fixing structural cracks).
2) Is it okay to perform this in winter in Northern California, as long as there is no rain?
3) I am also replacing the decking with pavers as the old decking is heavily cracked / settled. Given that we don't know the status of when the plumbing is done, is it worth upgrading the skimmer / return jets (leaving main drain alone with old)?

Thanks!

 

[AQUA~HOLICS]

1) Yes, this would be the most thorough process of correcting the situation. Are the cracks in any type of pattern? I have seen this happen before when the rebar cage is too close to the surface of the shell and without the proper coverage.

2) Yes, temperature and moisture from rain/snow are trigger points to not have the application of Shotcrete proceed at this time.

3) Replacing the skimmer and return lines would be recommended only if the locations needed to be changed for better performance or damage is revealed during the process.. This would be a judgment call at the time of exposure.

 

[veraj]

Thanks a lot @AQUA~HOLICS I will take some pictures of the crack to assess tomorrow.

Looks like in Bay Area, as long there is no rain forecast for the week, they will do the plaster. Is that right? or just moisture is a concern?

My skimmer is heavily settled & separated from the pool. So need to replace skimmer, and distance from skimmer to the plumbing pad is quite small. Hence, the idea to replace that. Other pipes are old as well -- I think the last time the pool got any work done is after the Loma Preita earthquake. Don't have the history / details as we just bough the home few years back. Deck concrete all around is broken / settled as well -- given we are going to break this and replace with pavers, we might as well change the return lines. Just keep the main drain plumbing, which is deep, and update the skimmer / return lines is what I am considering. Old pipes seem to be CPVC / grey type.

 

[AQUA~HOLICS]

Yes, it’s the amount of moisture from rain during the application process that is your concern.
With the amount of movement you are experiencing having the skimmer and other plumbing pipes replaced at this point in time is a good decision.

 

[veraj]

Yes, it’s the amount of moisture from rain during the application process that is your concern.
With the amount of movement you are experiencing having the skimmer and other plumbing pipes replaced at this point in time is a good decision.

Thanks again @AQUA~HOLICS Here are some pictures of the crack. Also, is it recommended to replace coping? except for the one area shown in picture, it seems to be in okay shape (grout / mastic needs fixing though).

 

[AQUA~HOLICS]

This is a judgment call on your half, if “ok shape” is good for you then I would leave it alone to keep the cost down.
Replacing the coping typically is done with the replacement of the tile at the same time.
This is hard to give advice on my end without seeing the pool in person.

 

[veraj]

We are planning to replace tiles and deck. If doing this later is an option and fixing one or two loose one works for now, it is preferable.

 

[veraj]

@AQUA~HOLICS The project is in progress with tile / plaster removed. There are cracks in gunite - mostly looks like hairline cracks -- may be structrual / due to soil movement as we have clay soil here & deck was separated from pool befoe (going to take care of the root cause leading to this). I am considering two options for a fix:
1) Torque Lock product (Torque Lock Structural Staples - TL-30 - Complete Staple Kit)
2) Cut around the crack, new re-bar and shoot shotcrete
(2) is the recommended option from the crew working on the pool, and I am worried if this is going to weaken the structure / create cold joints. Given the cracks are hairline, feels like torque lock like fix can be a good option here as there was no leaks from these cracks & not sure if this is going through the wall. End of the there are no warranties for these cracks and fixing the defect that led to cracks is the long term solution.

I would like to hear from the experts here on what is the right option. I also saw some videos (from Leaktronics that cutting all the way to dirt and pouring new shot crete is a bad idea).

Attached some picture and really appreciate help from this forum on the right solution.Thoughts?

 

[AQUA~HOLICS]

I am no expert on the subject, here are my thoughts.
I personally have never used any of the “staple” type products for correcting structural cracks in swimming pool shells, but have seen them used many times. I talked in length with TLSS at a trade show once and must admit that the components are the much more heftier than #4 rebar (see picture provided).
The common denominator with the structural flaws on the installations I was asked to look at was movement from improper compaction during construction and improper thickness of the SHOTCRETE application.

#2 would be the better option of the two you have listed.
As I stated earlier finding the reason for the cracks and correcting them will help ensure that the situation does not arise again. Hiring a company that uses the correct equipment can get you the correct answers (picture).
If the repair is done properly it will make the shell stronger than it is now with the cracks being present.
With SHOTCRETE applications there are no “cold joints” and the new product is as strong as the surrounding areas.
Preparation, thickness, PSI, hydration and other contributing factors are the key to success for the new product to adhere to the existing shell.

 

[ajw22]

Does the crew working on the pool who gave you option #2 have any experience with Torque Lock staples and could they do that?

Or did you get the best option they could do?

Your cracks do not look serious as cracks go. They are not wide and open. They are typical hairline concrete cracks.

Are all the cracks in the one corner shown in the picture above?

I would not cut out more gunite then necessary to put some form of concrete staples across the cracks.

 

[veraj]

Thanks @AQUA~HOLICS @ajw22 for your kind help / suggestions and greatly appreciate the same. Cracks are mainly on the corner (this showed up in plaster as well without leaks), other marked ones does not seem like cracks if you chip a bit more. Hence, feels like breaking gunite wall feels like a bad thing to do. The company I am using is a Gunite company and they feel confident only about shooting more Gunite -- they have a minimum charge to bring the equipment + extras for breaking all the way. They are okay doing staples -- but don't have the experience. They are also quoting a bit more than I would expect for a staple work, which would be minimally invasive. End of the day structural support is from re-bar and soil around. There does not seem be a badly shot gunite or something like that here. I can dig behind to see if any of these goes all way to other side. Since it is deep end, and pretty much entire wall is going to be broken down, I am hesitant on option (2).

 

[veraj]

Updating folks here. Plaster company insisted on breaking and shooting new gunite. Was not convinced it is needed, and went with crackstitch carbon fiber staples, epoxy sealing of big cracks (couldn't really inject anything on the hairline cracks), and then water-proofed with Miracote Miraflex Membrance C. Held up well over the rains when we had to wait for plumbing / backfill / deck fixes to provide additional support, and is now plastered with Pebblesheen, and deck work on-going. Hopefully cracks don't show up due to all the fixes done to deck. It has been more than 30 days since plaster and so far things are good except for cosmetic imperfections in Pebblesheen on the bottom that shows with lights.

Followed bicarb startup (minimal dust), and following TFP guidelines with liquid chlorine so far. Some pics of the progress.Thanks all for your help.