Cedar Shingles

[coopns]

Moved in 6 months ago. Shingles are in ok shape but trying to figure if they were treated and how to clean them up. I did spray
some bleach on a few and it didn't really take the black out which I assumed was mold. I was wondering if they were stained with
some type of shellac?

Did take down two big pine trees and about 2 miles from ocean.

Any thoughts on how to clean them up? Would a powerwash/bleach do it?

Pics in Google Drive...

Shingles
Shingles 1

 

[jalf]

If a 50-50 bleach-water spray allowed to sit for 30 seconds or so has no effect on the dark areas, then it's probably a tannin issue and not a mold issue. I would avoid using a powerwasher. The best answer may be to apply (1) a good stain-sealing primer; and (2) a coat or two of quality paint. I'd also add mildewcide to the primer/paint, just in case. Might help. Wouldn't hurt.

 

[maxdustington]

Don't paint them. Nothing screams cheap DIY like painting things that were never intended to be painted. It's going to look a lot worse once the paint starts to flake off.

 

[Onetor]

I had a cedar home. I pressure washed it in the summer. Bought Chevron oil 5 gallon (industrial, not motor oil) and sprayed them with oil. Must be done when it's hot and dry, so the shingles absorb the oil. May need two coats. I did not use bleach or any other chemical. Pressure washer worked awesome. Now you must wait for a couple days for the wood to dry before using oil.

 

[Kestas]

To prevent mold and mildew from forming on shingles you can nail strips of copper or zinc just under the topmost layer of shingles.

 

[Donald]

Originally Posted by Kestas
To prevent mold and mildew from forming on shingles you can nail strips of copper or zinc just under the topmost layer of shingles.


For roof shingles, not sure about house shingles.

Isn't the point to turn shingles like that a Cape Cod gray since you are near salt water? Ask the locals.

I would suggest a hose with nozzle but not a pressure washer. You do not want to open up the grain of the wood.

On painted clapboard cedar I have used https://www.homedepot.com/p/Zinsser-1-Gal-Jomax-House-Cleaner-and-Mildew-Killer-60101/100398378. Its the cleaner (detergent) part you mix with beach. Some scrubbing for the really dirty areas. Then rinse.

I would end up with a clear sealer that is oil based. I would never use more than a semi-transparent stain on the siding. No solid color and no paint.

 

[jalf]

From the look of the photos, you're probably past the stage where you can simply clean and apply more stain. I would be surprised if anything you try achieves uniformity of color. I'd guess your situation is similar to an old deck that's been stained repeatedly for 10 years. At some point, paint is the best solution. And, of course, paint protects the wood better than stain or a sealer because it more effectively blocks ultraviolet.

 

[SeaJay]

By me, they do not take long at all to turn dark brown and black in some cases. Not really a good choice if you are not in to frequent cleaning and maintenance.