Mastic Choices

[strongcedar]

I purchased a house with a pool that was devoid of mastic between the coping and the deck. Just an empty track all around the pool. I'm fairly handy, and would like to fill in the joint myself, but unsure of the right substance.

I've found several outlets for pool mastic online, and I'm sure I can go to the local pool store and buy some. But HD has tubes of "joint compound" that is used to fill in the expansion joints between concrete (sidewalks, driveways, etc). Is this the same material as pool mastic?

The pool is 17x34, so I have 100+ linear feet to fill. I'm open to any suggestions on what to buy and how to apply it. Thanks!

 

[duraleigh]

How wide and how deep is the joint?

 

[strongcedar]

Varies between 1/3 and 1/2 inch in width. The depth is trickier - looks like 1/2 to 1 inch deep right now, but I'm unsure if I'm supposed to try and dig out dirt and debris that's accumulated over the years. If so, the depth will be a little more.

 

[duraleigh]

I would use polyurethane caulk. It's harder to work with than silicone but it remains very pliable and does a great job.

You can get "backer rod" to reduce the amount you use. Backer rod is available in varying diameters. It is a "foam rope" which you push down into the crack so the caulk will not sink further into the joint after you apply it.

I have seen limited sizes in Home Depot and a wide variety of it at Supply houses that cater to concrete contractors.