Cedar Fence - To Clean or Not

[Larva 14]

I have a 5 year old cedar fence. It has never been sealed or stained. I figure it is time to take care of it (well, past time actually, but that's besides the point).

However, I'm not sure what to do about a certain situation. The fence is mostly gray, but also has some almost black sections (mostly along the bottom, perhaps where some sprinklers hit it). I tried lightly pressure washing the fence, and used a fence cleaning solution, but the black didn't come out. However, if I use higher pressure and take my time (about 15-20 minutes for a section between two posts) the black comes out.

I did this higher powered spraying on one small area to test. The end result is that this section looks almost the color of cedar again.

My questions are:

Is it worth my time to do this to the rest of the fence? It will look nicer, but will it really help increase the lifetime of the fence or help the stain set in better?

If I don't do this, am I just trapping in some sort of grime and mold that will actually decrease the fence's life?

[big mike 14]

Derek,

First, are you related to Dale? If so, call me up.

As to your fence, the black is caused by the iron in your water. It's a reaction with the tannins in the cedar. Your fence needs a good percarbonate cleaning followed by an acid application to remove the gray and black stuff. High pressure cleaning like you described will work, but you are decreasing the life of your fence because you're removing the soft fibers in the cedar. This will cause a raised grain in the wood, and you'll have a fuzzy fence. That method is time consuming and damages the wood, so it's not the best way to approach this project. FYI - fence maintenance is expensive, and its something they don't tell you about when they build it. To have a professional come over and take care of it for you, you'll be in the $5 -$8 per linear foot range, depending on the style of fencing and stain used. We're in your area, so call me up if you need some more info.