How to configure expansion joint

[RocketManTex]

I am about to start construction on an owner-build, so I'm sure this is one of many questions I will post. We're getting close to excavation, so this question came up, which could alter the forms/bond beam design.

• We plan to use stone coping and stone pavers. The coping is 12" wide and 2" thick. The pavers are 3/4" thick.
• We plan to have the coping set with a 2" overhang on the pool side, which will leave 2" of the bond beam uncovered on the back side.
• We can slide the paver over as close to the coping as necessary, but I'm unsure of how to configure the expansion joint adjacent/below that.
• Do we modify the bond beam shape in some way?
• Do we run foam all along the edge (as shown in red in my sketch), spanning just below surface all the way down to the existing soil?
• What do y'all think?

Thanks for any help on this!

 

[AQUA~HOLICS]

I would contact a steel engineering firm and see what they would require for a 10” bond beam, possibly #4 bar to replace the #3 bar all the way around the shell.

 

[ajw22]

The paver on top of the bond beam can cause problems and is not recommended. Adjust the length of the coping or the bond beam so you don't have that situation.

 

[RocketManTex]

Thanks guys. I picked a 2" overhang somewhat at random, trying to net something like 1" after finishing the pool. If I decided to minimize that, what would you consider the minimum overhang before tile/plaster?

 

[sktn77a]

Can you get 14" coping so you can keep the 2" overhang?

 

[Cena_sea]

I recall there being 14 inch coping for certain materials. Our stone was available in 12 x 24 or 16 x 24 and builder chose 16 inch coping to use with pavers. Coping was also 2 inches thick but pavers were a different thickness too.

 

[RocketManTex]

I agree 14" or 16" coping would be preferred to avoid this issue. It's not available in the material we (my wife) prefers. It was really hard to settle on the material choices, so I really don't want to start that process over again.

We're done with pre-grade, so we're going to set the forms today and start digging the pool. The pre-grade elevation (of the ground) is at the bottom of the back of the bond beam, right before it slopes at 45 to the vertical cut for the pool. I'm going to set the forms based on a 12" bond beam for now. I think we can adjust the back side to change it to 10" later as long as we haven't started placing rebar.

@ajw22 said ...paver on top of the bond beam can cause problems... What type of problems?

 

[ajw22]

@ajw22 said ...paver on top of the bond beam can cause problems... What type of problems?

Coupling the deck to the bond beam which can put pressure on the bond beam and crack it.

 

[flynwill]

You might check with your structural engineer and see if the top out-side edge of the bond beam could have a 2"x2" 45 degree chamfer. That should allow you install the pavers up to the edge of the coping, with the appropriate expansion gap.

The other thought is a 2" wide strip of paver (perhaps a contrasting material) set in mortar on top of the beam at the back edge of the coping.

 

[RocketManTex]

What if I expand the width of the bond beam to include the first paver? This would result in a roughly 24" wide bond beam. Attach both the coping and paver to the bond beam, then introduce the expansion joint and then additional pavers after that? Has anyone seen that done?