2. I have rising damp under my home and the wood has turned black. How can I tell if it’s rotting?

In this situation, you have what is known as sapstain or bluestain mould. While this won’t do a lot of damage to timber, it may visually mask the onset of decay. The best way to determine if there’s rot is:

  1. to probe the timber with a flat head screwdriver. If the tip sinks in easily, you have rot.
  2. If the first test is positive, smell of the timber. If it smells a little like mushrooms, then it might be rotting.
  3. hit the timber with a hammer. if it sounds solid then it’s fine. If it sounds dull, then it could be rotting.
  4. drill one or two small holes in an area you think are suspect and capture the shavings.
    1. notice the resistance on the bit when drilling. rot is very easy to drill through
    2. notice the colour the shavings are. if its dark brown and its a blond timber, then its indicating rot
    3. smell the shavings and if it smells like mushrooms then it’s rot.
    4. rub the shavings between your fingers. if the shavings crumble then its rot

If you have ticked off a lot of positives from the tests above then it can become quite tricky to determine what course of action you need to take. If you have rot in the sub-frame or stumps, then you’ll need to call an expert such as a licensed builder. If you’re still unsure and you’ve had one or two indicators that there is rot above, call in the builder.

After you or a builder have established that the timber is not badly effected, or you’ve had to conduct repairs and replacement, and you want to treat the timber to prevent rot in the future:

  1. Check and improve ventilation under the house. Often the vents are cloged with plants or soil
  2. See if there is evidence of a leaking pipe, as that is a comon cause of dampness under the floor
  3. Apply No Rot Gel to prevent rot from spreading or re-occuring.
Category: Timber Issues