This discoloration is most likely caused by a combination of excessive tannins leeching from the wood and mildew growth.
Paint strip cedar shingle siding.
Many of these products come in cans or bottles much like paint.
If new shingle siding no need to strip or try removing old paint not that you could do this 100 anyway priming painting is one of a solid type coating apt to blister bubble chip or peel.
Apply the stripper to the siding with a paintbrush or spray it on if it comes in a spray bottle.
Work your scraper from the top of each shingle toward the bottom in steady even strokes with the grain of the wood.
Some sections of old unpainted shingles and siding may look darker than others.
This experience strengthens all other reasons not painting new cedar shingles sidings or roofs.
Get all the loose paint off.
Apply paint stripper to the cedar siding.
Step 4 let the cleaner sit on the cedar siding for 15 to 30 minutes.
Cedar shakes are cedar shingles that naturally weather and are resistant to decay.
As much work as it is use of a sharp pull scraper usually gives the best results short of chemical stripping.
The problem with machine paint shavers is that they dig into the original texture of the shingles.
Hold both blades of the scraper against the wood firmly but don t press so hard that it gouges.
Apply the wood cleaner to the cedar siding using a paint brush or roller.
You ll have to remove the mildew and prime the wood with a stain blocking primer.
The paint will begin to peel and the shingles may become stained and they will need to be repainted.
If the stripping compound has enough time to finish its work it will prove easy to pull the paint away from the cedar.
Like most wooden shingles however especially when painted they require care and maintenance over the course of time.
Reach the high areas or apply cleaner to the less dirty areas using a roller with an extension pole which doesn t allow you to apply as much pressure or elbow grease as a paint brush.
Follow all product instructions regarding the amount to use and the proper time to wait.