---
title: "What Is Pool mastic? Pool Glossary | Marina Pool Services"
description: "Pool mastic is the common name for the flexible sealant that fills the joint between pool coping and the deck."
url: https://marinapool.multisites.ai/glossary/pool-mastic
publisher: Marina Pool Services
phone: +1-817-896-1120
quote: https://marinapool.multisites.ai/contact
---

Surfaces and decks

# Pool mastic

Pool mastic is the common name for the flexible sealant that fills the joint between pool coping and the deck.

Many homeowners say "mastic" for any joint sealant. Over time, sun, heat, and chemicals dry it out. It cracks, pulls away, and lets water in.

Signs of trouble: dark gaps, hardened sealant that crumbles, weeds in the joint, or sunken deck near the coping. The old material must be cleaned out before new sealant goes in. Fresh sealant bonds poorly to dirty or loose old mastic. See [Deck-O-Seal](https://marinapool.multisites.ai/glossary/deck-o-seal) for the product Marina Pool Services uses.

[Marina can helpDeck-O-Seal & Joint Sealing](https://marinapool.multisites.ai/our-services/deck-o-seal)

## Related terms

-   [Deck-O-Seal](https://marinapool.multisites.ai/glossary/deck-o-seal)
-   [Expansion joint](https://marinapool.multisites.ai/glossary/expansion-joint)
-   [Coping](https://marinapool.multisites.ai/glossary/coping)

## Need a hand with your pool?

Call or text and tell us what your pool needs. Estimates are free for qualifying services, and same-day estimates are possible when the schedule allows.

[Call (817) 896-1120](tel:+1-817-896-1120)[Get a quote](https://marinapool.multisites.ai/contact)

![A pool technician working on an equipment pad](https://marinapool.multisites.ai/_astro/technician-equipment-pad.BW5xZMNY_Zum1K5.webp)