Gasketed vs Non-Gasketed Casket — Why the Seal Can Backfire

The rubber gasket running along the inner rim of a metal casket lid is one of the most misunderstood features in funeral merchandise. Funeral homes present it as a premium protective upgrade. The reality is more complicated — and in certain burial situations, the seal actively causes harm.

What the Gasket Does

A continuous rubber gasket creates an air-and-moisture seal when the casket lid is latched shut. Most metal caskets (carbon steel, stainless steel, bronze, copper) are available in both gasketed and non-gasketed versions. Wood caskets never have gaskets.

Gasketed caskets consistently cost $200 to $600 more than the identical model without the seal.

What the Gasket Doesn't Do

Under the FTC Funeral Rule, it is illegal for a funeral provider to claim that a gasketed or sealed casket will permanently preserve remains or prevent decomposition. No casket — sealed or otherwise — stops the biological process of decay. Warranties on gasketed caskets cover structural integrity during transportation and handling, not long-term preservation underground.

The gasket keeps out water and air for a period, but decomposition is driven by anaerobic bacteria that don't need outside air to function. A sealed environment can actually accelerate certain decomposition processes.

The Mausoleum Problem

This is where the gasketed casket becomes a liability.

When a sealed metal casket is placed inside an above-ground mausoleum crypt, the gasket traps decomposition gases inside the container. Anaerobic bacteria produce methane, hydrogen sulfide, and other gases as part of natural decay. Without ventilation, the internal pressure builds until it overcomes the seal.

The result: the casket lid can rupture, releasing gases and fluids into the crypt and the surrounding mausoleum structure. This isn't theoretical — it happens frequently enough that many modern mausoleums now explicitly prohibit gasketed caskets. Others require the rubber gasket to be removed before entombment.

When a Gasket Makes Sense

For in-ground burial inside a concrete grave liner (not a sealed vault), a gasketed casket provides some short-term moisture resistance during the burial process — particularly in wet climates or areas with high water tables.

For families who want every available layer of protection during the burial itself (the lowering, the closing, the initial months), the gasket delivers marginal peace of mind. It won't change the long-term outcome, but some families find value in that.

When to Skip It

• Above-ground entombment (mausoleum crypt) — many facilities ban sealed caskets outright
• Budget is a concern — the gasket adds cost without changing the biological reality
• Green burial — natural burial cemeteries require containers that allow decomposition, not resist it
• Cremation — casket seals are irrelevant for cremation

What to Ask the Cemetery

Before choosing a gasketed model, call the cemetery or mausoleum and ask directly:

1. Do you accept gasketed (sealed) caskets for entombment?
2. If not, do you require gasket removal before placement?
3. For in-ground burial, do you have a preference?

The Casket & Urn Selection Guide covers the gasket decision alongside vault type, burial method, and material selection — so you can evaluate the full picture before the funeral home steers you toward the higher-margin option.