Cedar roofs are organic and raw. Even pressure treated cedar roofs are still considered an organic raw material. Because the cedar roof is organic and natural it needs to have its natural processes supported.
Anyone who works with raw wood knows that the only way to support the nature of wood is by treating or finishing it with a stain.
After a cedar roof has been washed, it must be finished with an accredited roof treatment. Stains are the only products, at this time, that allow the natural respiration of the fibre in the cedar shakes to continue after treatment.
The use of acrylic paints, silicone based treatments and other topical sealants prevent respiration from naturally occuring. The result will be moisture being held inside the shakes causing premature rot.
Besides the decrease in the life of the cedar roof, topical treatments wear off over time and look down right ugly within only a few years.
I personally recommend Cedar Guard Roof Treatment. It is a stain that acts as a UV Blocker. It has natural tree resins that permeate the surface of the cedar shake and protect the fibre much like the natural protection does. Being a stain it supports the natural respiration of the wood.
Usage of materials such as linseed oil and other natural oils may support respiration but they do not have value since they decompose quickly.
Use of products such as marine oils and crankcase oil etc do not support natural respiration and are environmentally damaging.
The Cedar Guard products keep the roof looking “natural and new” for four or more years. I know of no other product on the market that can make that claim.