Does pex get brittle and break easy, or become unrepairable?

If your wires are brittle, you have fuses instead of breakers or have other problems, then they might need to put attention to them soon.

If your ongoing mode of operation has a risk point in it then some day it will surely bite you.  33 years later is too long to wait for a brittle balance arbitrage payoff, when you might have to refinance that 3 or 4 times (with a couple points to the mortgage broker every time).  

Those daily shower cleaners WILL make the surround brittle and subject to cracking.Ceramic tile HAS to be installed properly to adhere long term. 

We prefer the underlying material to be brass, not steel (rusts easily) or zinc (pot metal that is more brittle).

Of course, if all the iron is coming out, there's the tried and true smack it with a hammer - CIP is very brittle and easy to shatter. 

The plastic gets brittle and more and more parts will start to break.Are you responsible for replacing it, legally?

You may see slight variation in color due to fading, but it shouldn't be too bad, especially since it isn't a color.If the shingles are old enough to be brittle, this may not be a workable option.

The linoleum was so old the top skin was brittle and breaks off leaving about an eighth of an inch of hardened something? 

Dana:If you know how maple syrup and maple butter/brittle is made - the sap is reduced until it becomes a syrup or paste/solid - then you have the basic idea of how shatter (or a similar product called 'Wax') is made.Now substitute hash oil for the maple sap and reduce it into a thick syrup.