The old fence is like part of the home, and part of the landscape.
The problem is that old fences can be very dangerous, unstable, and if they're really old, hard to repair to anything like a good standard.
They're also likely to come as an expensive surprise if a new neighbor wants to replace them, so it's worthwhile talking to your local fencing contractors before you need to go into damage control mode.
Signs of a fence that needs to be replaced The signs aren't always obvious.
Some fences are so tough they look OK-ish, but there are structural issues you need to check:

• Supports loose: If the fence moves, it's a sign the whole fence is under stress from gravity.
  Fences can be literally uprooted overnight.
  They can also take a lot of garden soil with them, letting in weeds and parasites.
  
• Wet areas: If the supports get damp, they can also move, which can pull down sections of fence and affect other parts as well.
  
• Mold, algae and signs of rot on timber fences: The fence's treatment has hit expiry date.
  These factors will progressively destroy sections of timber fences.
  
• Cross beams out of position: Warping is uncommon, but if the cross beams are out of alignment, something else has moved.
  This is a structural issue which may or may not be fixable.
  Note: On steel fencing, nothing is supposed to be out of alignment.
  Check and see if you can see the problem.
  If you've got a Colorbond fence, there may have been ground movement you really do need to know about.
  
• Termites: Any sign of termites means the fence is in real trouble.
  It's probably very old, and these pesky insects can do terrific damage in a hurry.
  Try to identify any specific areas, because you'll need replacement fencing in those areas at least.
  

Important: Any indication of general movement of a fence does have to be dealt with immediately.
You could be looking at a lot of work, if you don't act fast.
Checking out a replacement fence The only good thing about these situations is you'll be able to get a good modern fence which is far more resistant to these types of issues.
Modern treated pine timber fencing is practically indestructible and very long lasting.
This is also an opportunity to make sure you get the fence you want.
If you want a particular look or design, a new fence can fix both problems at once.
A bit of shopping around can find both good prices and good products.
It's advisable to do your fence-hunting online to get an idea of the market prices.
Check out the local professional fencing supplies businesses range of products first.
You'll be surprised to note that their deals are often as good or better than some of the top of the range products.
Many fencing companies, particularly franchises, source from manufacturers direct, and can do a better job for less.
There products are top market standard, and because they're local, they're cheaper.