If you have severely stained Cedar siding, you can power wash it with a wide nozzle and low pressure. Cedar siding is durable but can be damaged easily by excess pressure, especially when it is aged or very dried out. You should only use a wide nozzle, because the narrow stream of a straight nozzle is capable of drilling a hole in the soft cedar.
Let me expand on this:
First, make sure the siding is fastened well to the house. Even at low pressure, you can break loose cedar shingles. If you have to secure any loose shingles – ONLY USE SIDING NAILS! (other nails may rust or corrode and streak the siding). If you don’t have – or want – a power washer, You can even use garden hose with a pressure sprayer head like this:
Crusar Brass Water Jet Power Washer High Pressure Hose Nozzle Pressure Sprayer for Car Washing Vehicle Washing Pet Washing Gardening Outdoor Housecleaning Window Cleaning – From Amazon, it uses 60 PSI home water pressure, not 1800 psi power washer pressure. I have one and use it for light duty work.
Second, using a good cleaner BEFORE power washing to remove and brighten the siding will make the job easier with less power washing.
Cedar siding is one of the best natural siding materials for your home. It is attractive and resistant to pests and weather. Keeping it maintained is a very smart investment for your home!
I hope you found my point of view enlightening and informative.