Need for expansion joint or not

[bvgas]

I've read mixed feelings regarding the need for an expansion joint between coping and patio. My pool has a both a brick coping and patio - Same exact bricks - In Northeast - Nassau Bricks - approx 4 x 8 size.

I had my pool & patio redone and the company that did it did a poor job on the patio portion in terms of details but they did place an expansion joint approx 3/4" thick of some spongy material between brick coping and patio - stating it was absolutely necessary. I'm currently redoing the patio portion because we were so unhappy with how it looked. The new mason who seems to know what he is doing and comes highly recommended feels that an expansion joint is not necessary in the case of our pool. He made reference to the way the concrete beam extends just beyond the brick coping & and laying brick patio portion in sand and special interlocking polymer to be used between bricks obviate the need in MY CASE for the expansion joint. He is not against expansion joints - he just feels in my situation not necessary. The prior expansion joint looked very unsightly so I wouldn't mind not having one but on the other hand I don't want to regret it later on. Any opinions? thanks

 

[JamesW]

What is the width of the deck?

How will the outer edge be done to lock in the brick?

 

[bvgas]

I'm not sure - I will have to check what he is planning. The outer edge will also be brick. Under what circumstances would how you lock it in alter the need for an expansion joint?

The width of the deck varies - on the long sides it is approximately 17/25 brick widths. On the short ends 17/>30 brick widths

 

[JamesW]

A wide deck with a solid outer border will expand and contract enough to break the coping loose within a year in many cases. A narrow deck with a less solid border might do ok without an expansion joint. If the outer bricks can move, that allows stress relief when the deck expands.

Materials expand and contract as temperatures change. Without an expansion joint, the structural integrity can be compromised.

In most cases, an expansion joint is good insurance. If they are done properly, they can look good. If your old one looked bad, it was probably poorly done.

Bottom line, I would recommend using an expansion joint.

 

[pooldv]

I agree, expansion joint is needed.

 

[bvgas]

If the bricks that make up the patio are filled in with polymeric sand - not cement - wouldn't expansion more likely dislodge the sand or move individual bricks rather then the pool coping? It's not like the bricks are a solid sheet (like a large slab of concrete) nor are they cemented down - they are on sand. I would think these would points of lesser resistance and absorb most of the expansion and contraction rather then the cemented coping.