Believe It Or Not, It's Just "Hanging In There".

 Believe It Or Not, It's Just "Hanging In There".

Yes believe it or not this is rot.

Ordinary wood rot is the process of decay due to the breakdown of the wood fiber components as they are exposed to mold, micro-organisms, insects and water. This is a complete ecology with the mold eating the wood and other things feeding on the mold and weakened wood and others feeding on them, etcetera, etcetera.

It can occur right before your eyes, as in this case, as well as in hidden locations. Primarily all that is required is the relatively frequent recurrence or constant presence of water. Other than that it's the right temperature range and the ubiquitous presence of mold spores and the rest of the micro-biology team. (They're always waiting in the wings.)

Here this is outdoors on a secluded corner of the veranda, and the caulk that was used to 'seal' where the wood and concrete touched is still there.  Caulk only works between some materials, in drained conditions and is the back-up to proper flashing or other separation controls. Caulking instead of the classic separation and flashing details will only work for a short time.

Here's the shocker (for some);Believe it or not -  Just like copper is a conductor for electricity, concrete (and cement and masonry) conducts water.  It does not have to be cracked or broken to transmit water to wood in contact with it. Just being in touch, in contact is sufficient.

That's why framing sills (mud sills) and basement wall shoe plates have to be gasketed between the wood and the concrete. Old school material was tar paper. Now there are rolls of foam plastic/vinyl gasketing available in widths to match the dimensions of the wood.

So in this case the caulking sealed out nothing. It actually prevented drying of the wood here which would have preserved it longer.

The concrete conducted water to the face end of this 4x4 column and the end grain would draw in the water by capliarry action, similar to a straw but driven by chemical affinity rather than suction forces. This is how water moves in the living tree.

So evert time this concrete surface got wet from weather or garden watering it delivered water to the wood. The paint and caulking kept the water in place so the wood rotted.

Believe it or not, this was pressure treated wood. The rest of the column is dry and has no rot.  The guaranty or warranty instruction for this product promises that it will last for 20 years outdoors provided it is not in contact with water or water retaining materials. It can even be in ground contact as long as it rests in a drained gravel bed.

Fortunately for this homeowner this column is not structural. It's just "hanging in there".