Following is pasted from Radiantec's (my vendor) website FAQ:
How long will Radiantec tubing last?
All Radiantec tubing is made from high-grade polyethylene, the material of choice in applications demanding long life and high resistance to chemical and environmental threats. Radiantec guarantees its products from age-related breakdown for 30 years. There is good reason to expect the material to last for 100 years and some environmental scientists maintain it will last for 600 years.
What would happen if tubing breaks within the slab?
This type of damage is most unusual, but once located, can be fixed in one hour with the use of a $5.57 repair coupling and a hand chisel. Radiantec recommends the use of glue, rather than a nail gun, when installing partitions to minimize this possibility. By installing several parallel rather than one long circuit, as Radiantec recommends, it is often possible to bypass the leaking circuit and avoid repairing it altogether.
