Question about expansion joints

[Pierrot]

Hi all,

I need to redo the expansion joints around my pool. I'm planning to follow the advice given on that thread => How to Replace Your Pools Mastic - Complete Guide by a Pool Newbie

I just have one question: the patio around my pool is composed of concrete slabs. Should I use the same product (deck-o-seal or sikaflex) for the joints between the pool coping and the concrete slabs and for the joints between the concrete slabs themselves? Because from what I see, that's not what the previous owner did.

Thanks!

 

[PoolGate]

Are the concrete "slabs" actually individual castings? If so then use the regular sealer I suppose. But if it's just an expansion joint designed to crack then it doesn't really need anything.

 

[ajw22]

No, the joints between the slabs are for crack control and are not expansion joints. You do not use flexible mastic between slabs.

 

[Pierrot]

Are the concrete "slabs" actually individual castings? If so then use the regular sealer I suppose. But if it's just an expansion joint designed to crack then it doesn't really need anything.

The concrete deck doesn't seem to be composed of individual castings but rather continuous pour with control joints (I guess?). So maybe the term "concrete slabs" wasn't correct, my bad.

No, the joints between the slabs are for crack control and are not expansion joints. You do not use flexible mastic between slabs.

When I look at these crack control joints, most of them are already cracked (so I guess they did their job - see picture attached as an example). And water does infiltrate them. Couldn't that become an issue?

 

[ajw22]

Cracking is what concrete does and why control joints are placed so the cracks go there.

There are concrete crack fillers in your local hardware store.

 

[Pierrot]

Cracking is what concrete does and why control joints are placed so the cracks go there.

There are concrete crack fillers in your local hardware store.

Would using Deck-O-Seal for control joints work anyway but would just be overkill because control joints don't move as much as expansion joints and don't need flexible sealant?

Or would it actually be bad to use Deck-O-Seal in there?

I'm asking this because I already bought some deck-o-seal stuff

 

[ajw22]

Would using Deck-O-Seal for control joints work anyway but would just be overkill because control joints don't move as much as expansion joints and don't need flexible sealant?

Or would it actually be bad to use Deck-O-Seal in there?

I'm asking this because I already bought some deck-o-seal stuff

It would work okay but I think you will find the joints will look thick and messy. I also think the deck-o-seal may not hold up in some high traffic areas.

 

[Pierrot]

Awesome, thanks @ajw22 and @PoolGate for the guidance