Correct way to repair cracks at the level of the bond beam (cracked tile)?

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My next project,

Good Evening all, I am relatively new to this forum and have found a lot of useful information. This my first post.
We are in the process of having our pool refinished and I have a question as to the best way to correctly repair cracks at the level of the bond beam.
Pool is 30 years old, never been resurfaced. Shell is otherwise in good condition.

We have several areas of our pool which have cracks in the waterline tile. The spa has opposing cracks along the level of the bond beam on both the inside and outside of the spa which is particularly concerning as it appears that the entire bond beam along the top of one side of the spa has shifted.

The pool resurfacing company wants to V out along the cracks, fill the cracks with mortar and apply tile.

I have attached images of the cracks (all have been V cut by the pool resurfacing company except the spa.

Any suggestions, recommendations or comments would be appreciated.

Thanks,
Darren

 

[AQUA~HOLICS]

First you need to correct the reason why their is pushing on the bond beam.
The deck will expand with heat and that expansion needs some where to go so a expansion joint needs to be installed on the deck clear through to dirt.
The method that the remodel company is using is common (removal of loose materials) and works if the reason for the cracks in the first place is also corrected.

 

[kimkats]

I am in to learn from this one. @AQUA~HOLICS thanks for stepping in on this one.

 

[NextProject]

Thank you for your reply Aqua-Holics. I believe the problem with the pool stems from the cantilever design of the deck with no expansion joints running along the coping. While there are expansion joints along each adjacent section of pool deck, there is no expansion joint along the coping edge (i.e. 12 inches in from the pool edge) There are no cracks in the pool deck. Each section of pool deck appears to be in plane with the adjacent section (minimal settling)

Each section of pool deck is poured concrete, 4 inches thick, roughly 5 feet by 5 feet and about 1100 lbs. The pool deck is surrounded by a wall and the deck sits against this wall. The wall shows little signs of movement and there is no expansion joint between the deck and the wall. Any expansion and contraction must therefore push all 1100 lbs towards the pool edge. In most areas around the pool the tile is in direct contact with the bottom edge of the pool coping.

The spa is a different story. I have no idea what caused the opposing cracks along the tile lines of both the inside and outside of the spa. Any ideas. The 14 inch wide deck which sits on top of the spa is level and without any cracks.

Thank you again for your reply and any comments or suggestions are appreciated.

Darren

 

[AQUA~HOLICS]

Of the pictures you supplied are any of them of the opposing cracks in the spa tile lines and if not can you supply some?

 

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Here is an image of the top of the left side of the spa with cracks on both the inside and outside of spa at the level of the bond beam. When the spa was at the correct level water would actually leak out of the inside of the spa and run down the wall on the outside of the spa into the pool.

 

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The 3rd, 4th pictures are the inside of the spa and the 5th and 6th pictures are the outside of the spa. The are approximately at the same level when measured down from the coping and approximately the same length.

 

[AQUA~HOLICS]

Possibly this crack is from the application of the Shotcrete itself and that at first the spa spillway was much wider and was made narrower at a later time, either in the same day as the original shoot or years later and the preparation of the old and new was not clean enough to provide a good bonding between the two.

 

[NextProject]

What you say makes sense as far as the pool is concerned as far as expansion. Do you think cutting an expansion joint along the wall rather than close to the coping would be effective in allowing expansion for each slab section? Any ideas on why the left side of the spa cracked?

 

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Do you think that V grooving the crack on both sides, filling the crack with mortar on both sides would be sufficient for the spa?

 

[NextProject]

You're assessment of a possible cause for the spa cracks makes sense. Unfortunately, we did not own this home when the pool/spa were originally constructed so I don't know if there were any modifications made to the spa.

 

[ajw22]

Do you want a permanent fix that should not crack again or do you want a fix where it will crack in a few years?

A “decoupling” expansion joint should extend across the entire width of the top of the bond beam to allow the deck to move independent of the pool shell. This joint can be created with a 4mm plastic sheet or 2 layers of roofing felt underlayment.

It is very important that the waterline tile is installed after the deck is placed so there is no chance of the deck expanding and popping off the tile (see tile placement in the diagram). The tile can be grouted as usual but the top joint between the deck and tile should be filled with a flexible sealant that is not silicone based.

Either your deck was installed without the slip joint or somewhere in it's life the joint was filled in.

If you don't create an expansion joint by repouring the deck or by saw cutting around the coping to create an expansion joint like shown below the bond beam will crack again.

 

[AQUA~HOLICS]

Creating an expansion joint near the wall is where I would locate it. Needs to be cut deep enough so it reaches the dirt then cleaned out and backer rod used at the proper depth ( do not use sand ) then a Deck-o-Seal product to fill the expansion joint.
Unkown on why the left side of the spa cracked.
Same repair method as the pool bond beam can be used on the spa.

 

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Thank you AJW22. The images are helpful. Prior to the tiles being removed I inspected the grout line along the tile. Grout came into direct contact with the coping around the entire edge of the pool and spa. There was no flexible sealant used. I agree with you on cutting the expansion joint. I asked the pool remodeler about cutting and expansion joint and he explained that while it would be beneficial for sure he has seen cases where the deck left sitting on the top of the bond beam would pivot (like a teeter totter) and the outside part of the deck would settle and slope towards the pool. These were his words not mine. Personally I think I would rather the expansion joint. I agree with the flexible sealant. I think that the tile was attached to the deck by the mortar.

 

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Thank you Aqua-Holics. I will ask the pool remodeler to cut an expansion joint near the wall and fill the joint with Deck-o-seal. AJW22 would you suggest that I ask the pool remodeler to make a small cut where the top of the bond beam comes into contact with the pool deck, make certain the newly installed tile or mortar does not come into contact with the pool deck, and fill the joint with a flexible sealant?

 

[ajw22]

Well no one knows what the base is under the deck and if the deck is sitting on a firm base or it is balanced on the bond beam.

The best fix is to demo the deck and coping so you can see what the deck base is. Put precast coping on the pool and the deck of your choice with an appropriate expansion joint between the precast coping and the deck. Prepare the subsurface as needed for the new deck.

Cantilevered coping and decks eventually cause problems like this as the pool ages.

 

[ajw22]

Thank you Aqua-Holics. I will ask the pool remodeler to cut an expansion joint near the wall and fill the joint with Deck-o-seal.

The saw cut needs to be completely around the pool to decouple the deck structure from the pool structure. That creates an expansion joint like shown with the precast coping.

AJW22 would you suggest that I ask the pool remodeler to make a small cut where the top of the bond beam comes into contact with the pool deck, make certain the newly installed tile or mortar does not come into contact with the pool deck, and fill the joint with a flexible sealant?

No, that will not decouple the cantilevered deck from the bond beam. You would need to make a horizontal cut the entire depth of the bond beam to try and properly cantilever the deck over the bond beam. And then it would not last because you would lack the plastic sheet or roofing felt to keep the joint open.

 

[NextProject]

I agree with you ajw22. The idea of sitting thousands of pounds of concrete that moves on top of the edge of something that breaks if there is movement is a recipe for failure. While I would prefer to demo the deck and use precast coping I was trying to avoid it.

 

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The other thing which dissuades me demo of the deck is that there are only the areas mentioned. The remainder of the pool has no cracks anywhere and there are no cracks in the deck. Do you think it would be beneficial to just demo those two sections (between expansion joints) which have a problem?

 

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Aqua Holics, thank you. I will ask the remodeler to cut around outside edges. There will be some variation as the pool itself is an infinity pool on one side with large 10 foot long planters on each side of the infinity edge.