12/10/2022
MUST READ!! About 95% of the roofs we treat and clean here in San Diego have ‘California Gold’ infesting them. This is great information about what it is and how we approach safely removing it from your home. Thanks to SoftWash Systems, our partner for training, equipment, and chemicals, for the excellent explanation.
Thus is what we call CALIFORNIA GOLD LICHEN. It is colorfast (won't bleach). Usually grows along apex or cap tiles. Sometimes on shingle roofs but mostly tile roofs. Usually a coastal lichen. Likes salt air. One theory is it grows on the apex because of nutrients deposited there by bird droppings.
This CALIFORNIA GOLD LICHEN requires a 4 to 5% mix of SH, water and a strong antimicrobial surfactant like SoftWash Systems Green Wash. Will require 3 treatments because it's on the apex of the roof and drys out quickly because of no chem above draining down to keep it moist du ring treatment. IT WILL NOT BLEACH CLEAR however that does not mean you did not kill it.
https://shop.softwashsystems.com/green-wash.html
DO NOT WALK ON THE TILE ROOF!
Allow time, rain and mother nature to weather the dead lichen away. If you must remove it quicker rinse it with water and agitate it with a brush on an extension pole. After 3 treatments of hot mix it will get soft and can be scrubbed away.
NEVER USE A PRESSURE WASHER ON A ROOF, ESPECIALLY A TILE ROOF. Why on a tile roof especially?
1. Because you can only pressure wash it from on top of it. That is dangerous and you may fall off the roof or break roof tiles.
2. Heavy infestations like CALIFORNIA GOLD LICHEN usually have erosion beneath because all mildew, algae, molds, LICHEN and mosses are decomposers. Pressure washing a decomposer off a tile roof will remove the finish from the tiles.
Here is a video from England removing this GOLD algae.
https://m.facebook.com/watch/?extid=CL-UNK-UNK-UNK-AN_GK0T-GK1C&mibextid=2Rb1fB&v=1706820759412241&paipv=0&eav=Afa5f_mWsbe3LUhbXW9IWVz6XEipSCAkdAo5w4p5iqZ5Wo22PETHOd3Px8wNjUuDLiU&ref=sharing&_rdr
IT IS BEST TO TREAT AND ALLOW MOTHER NATURE TO FINISH THE REST.