Do pressed/retail DVDs degrade like recordables do?

[Marcos]

So now that DVDs are getting to the £3-£5 range, im slowly rebuilding my collection of favorite movies with something more permanent

But what is the life of a retail DVD movie? Is it safe to "invest" in them for my favorite movies? And expect them to last 10+ years?

[Agent]

Pressed disks do not degrade in the same way as writeable ones, but do degrade.

Writeable disks degrade due to dyes / inks / burning process changing on a chemical level.

Pressed disks are based off aluminium (IIRC) where the data is physically "pressed" into the metal (Think of the progress being similar to pictures on a coin).
These can still degrade, yes, but at a considerably slower rate than writeable disks.

This says it in more detail:

CD-ROMs and DVD-ROMs are similar in that they are replicated discs—that is, the data are physically pressed into the disc when it is manufactured. ROMs are generally mass-produced and contain music, video, computer applications, or interactive games.

ROM disc longevity is determined by the extent to which its aluminum layer is exposed to oxygen. Oxygen, including pollutants, can migrate through the polycarbonate layer or the hard lacquer layer (CD label side and edge), carried in by moisture. Oxygen or moisture can more easily penetrate through scratches, cracks, or delaminated areas in the label. Oxygen can also be trapped inside the disc during manufacturing, although manufacturing improvements have reduced the likelihood of this.

If left in a very humid environment, moisture—and oxygen—will eventually reach the aluminum, causing it to lose its reflectivity. The normally shiny aluminum, which resembles silver, becomes oxide-dull and much less reflective, like the color of a typical aluminum ladder. The combination of high humidity and increased temperatures will accelerate the oxidation rate.

The life expectancy of a ROM disc therefore depends on the environmental conditions to which it is exposed over time. Generally, it is best to keep ROM discs in a dry, cool environment. If the disc is removed from a humid, hot environment to an ideal condition before damage has been done, it will "dry out" and should be as playable as if it had been kept in ideal conditions all along. Other contaminates, however, such as inks, solvents, and pollutants, have the potential to irreversibly penetrate and to deform, discolor, or corrode the disc, causing permanent reading problems for the

Care and Handling of CDs and DVDs: A Guide for Librarians and Archivists

In short - Don't worry about it. Just don't leave them in sunlight or the bath and its almost certain they will outlive you

[Funkstar]

The problem with recordable media is the active chemicals in the recording layer. They are ususall organic compounds these days I think. This makes they suseptable to damage.

They are made from just polycarbonate and aluminium foil. There has been cases of CDs (which use the same basic manufacturing process) becoming damaged when the aluminium foil oxidises making the disc unreadable. A Philips manufacturing plans produced quite a lot of these at one point. DVDs do have a top layer of polycarbonate though as opposed to just laquer to they are far less likely to be damaged this way.