I have old cedar shingles with existing red stain.
I want to clean them and re-stain with a lighter tan shade stain.
First, what's the best way to clean these shingles? I've got a Karcher power washer, but the manual says not to use bleach (or any other corrosives), which means I can't use the Cabot Problem Solver Wood Cleaner I was planning on. I'm sure I need to kill the mildew with something, and using a power washer seemed like the way to go. Help...
Second: We moved into this house last year and last summer I used a semi-solid stain on some of the shingles that really needed help. But now my wife wants to change the house color from red to tan. What are my options? Can I cover a semi solid stain with another semi-solid? Or because, tan's a lighter color, do I need to try to cover up the red with solid stain?
You can try using a tank sprayer with whatever cleaner you want, brush it in for best results, and then powerwash. One reason companies caution against running things with bleach through a powerwasher is that it will atomize into chlorine gas.
If you are going with the color change you have in mind, a good quality paint store solid color stain will be your best bet. I would use latex acrylic once you jump to solid stain. MAB used to make a great solid color stain product. They were purchased by Sherwin Williams awhile back so hopefully it has been folded into the line.