Cement Deck sag - ideas to repair

[mikee30]

Hi,
I have a in ground pool with vinyl liner that has a cement deck all around it (roughly 3ft wide). The deck was poured in the mid 80s and since then has developed some flaws I would like to take care of.

The two longest parts of the cement deck (picture a rectangular type pool) have sank considerably. One side of the pool (the side that has a skimmer in it) sank roughly 2 inches. 2 inches refers to the back side of the cement deck, furthest from the pool liner. The other side of the pool deck (that has lighting holes), sunk roughly 1 inch.

When doing a repair last year, I had to break a small part of the cement and noticed that there is a gap underneath the deck of a few inches. I had a company come in to quote doing an injection, to lift the slab, but felt the cost was not worth it, given the age and condition of the cement. Most other companies suggested breaking all the cement and re-pouring new cement (or using pavers), however, this becomes a major project.

Has anyone ever tried to lift their cement slab with a few jacks (10t or more) and backfill underneath with rocks/blocks?
Alternatively, would there be any harm in adding a layer of cement on top of the existing cement deck to level it off everywhere? I don't know how well a cold joint between the old/new cement will hold up during winter, but it is something I can try. The cement around my stairs and diving board has barely moved
Last idea is to wait until I need to change my liner and make that the year of a major overhaul to the pool!

Any ideas would be appreciated!

Thanks

 

[tim5055]

Google "Slabjacking" or "mudjacking" or "pressure grouting" in Montreal


Concrete leveling - Wikipedia, the free encyclopedia

Basically they drill a hole int he concrete and push mud/grout under the slab and raise it to where it should be.

 

[mikee30]

Google "Slabjacking" or "mudjacking" or "pressure grouting" in Montreal


Concrete leveling - Wikipedia, the free encyclopedia

Basically they drill a hole int he concrete and push mud/grout under the slab and raise it to where it should be.

I called a company that does that and the price was almost the same as installing new pavers (if I broke the cement myself)... They inject polyurethane to lift the slab

 

[gwegan]

Yeah, you are learning the bad news. Generally with an old deck its best to jack it out and replace. It sounds like you may have had leaks under the deck that scoured it out. You might want to figure out what the process is and fix that if its still happening.