How to finish rough sawn cedar weatherboards?

[PujDD]

Hi all,

I've bought a house that needs some work. The existing weatherboards are rough sawn cedar stained with a semi-transparent walnut like finish. On 3 sides they need a bit of TLC due to varying levels of mould/mildew. The 4th side, the boards are cupping and rotting beyond repair. They need a full replacement, which I am getting a licensed carpenter to do. 

I'd like to take the opportunity to clean and refinish the existing boards alongside the new boards to protect them for the next 4-5 years and to keep a fairly consistent look to the home's exterior. 

I'm overwhelmed by the choices between oil based, water based stain and paint. A lot of people I've spoken with swear by oil based stains being the longer lasting option as it "seeps into the boards", where others say the complete opposite and that modern water based stains can be penetrative as well. I'm not the biggest fan of the block paint finish, but I have had a solid block paint finish recommended to me also as the most sure-fire way to achieve a consistent finish that hides imperfections and inconsistencies in the wear levels. 

I'm also stuck on the prep work involved. The boards on the east and west side look in fairly good shape to hold up against a power wash, and the boards on the north side are being replaced with all new weatherboards so no stress there. The southern face is fairly weathered and I'm concerned about excessive splintering or other damage from a power wash. You can see evidence of an attempted power was from some time ago (the grey patches of the southern elevation)

I've had a few painters come through to provide quotes, and they couldn't be more different: 

1. Power Wash followed by oil based stain (cheapest) 

2. Power wash followed by solid block paint (35% more than Option 1) 

3. Oxygen Bleach followed by dark water based stain (60% more than Option 1) 

4. Full sand followed by water based stain (95% more than Option 1) 

I'd like to avoid the full sand as I Don't really have the budget for it, but push comes to shove I can make it work if none of the cheaper options are suitable. I guess that's why I'm looking to the brains trust for advice -

1. based on the pictures (particularly the south elevation), how risky do you think a power wash is?

2. Is oxygen bleach effective to prep the boards for stain instead?

3. Given the state of the southern face, is a block paint really the way to go or can I get away with a semi-translucent stain? 

Images attached for reference. 

Thanks for your help! 

[MitchellMc]

Welcome to the Bunnings Workshop community @Simpaler. It's sensational to have you join us. Many thanks for jumping into the discussion.

Let me tag @PujDD so they are alerted to your question. Hopefully, they'll be able to answer it for you.

We look forward to hearing all about your projects and plans around the house and garden. Feel free to reach out anytime you need assistance or have something to share with the community. 

Please let me know if you have any questions.

Mitchell
 

[PujDD]

Hi @Simpaler it was the intergrain universal timber oil mixed in with the rusted red pigment. I can’t recall our dilution ratio but it was slightly milder than the recommended ratio. 

we only did 2 coats and were happy with the consistency and colour. The first cost absolutely drank in though and wasn’t enough. Sanding was key!!