Fixing peeling paint on timber cladding

Question

The paint applied to a section of timber cladding (outdoor) has failed to adhere to the to the timber as evidenced in the photos below:

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The paint was applied in the same year as the timber was installed, which is approximately 2 years ago. The peeling/flaking stated appearing within a year and exhibits worst conditions on south/south-westerly elevations (where the sun shines most in this side of the world).

The timber is reportedly Douglas Fir (unclear if it was treated or untreated), and the paint is Bedec Barn Paint (Acrylic based), which appears to have good reviews.

I do not have the history of how the paint was applied (how many layers, whether any primer was applied, whether it was brush painted or other,...).

The photos above show:

1. different degrees of peeling/flaking (not uniform across all planks. There appears to be a correlation with the wood grain and the level of peeling
2. Peeling follows grain pattern
3. Same as above (no peeling between grains)
4. Same as above

Any suggestions on:

1. what the cause(s) of the peeling/flaking may be?
2. how to remedy?
3. what further questions to ask from the contractors who conducted the work that would help establish the above?
4. any tests you would suggest would help with the above?

Answer 1

There are multiple reasons for outside paint to peel and crack. It can be hard to pin down if it is a application issue or just an outside factor. But as you state it was applied on newly installed (non-aged) wood has me tending toward that aspect.

Based on the product data sheet DATA SHEET the following is listed, "Pressure treated timber should be weathered for 6 months. Denatured wood should be abraded to reveal new cells. Any new finished wood needs to be abraded." So was the wood sanded prior to the first coat?
I myself would lean toward this thought if I was more familiar with the paint itself. This would be do to the fact I do not see paint staining of the cells in the underlaying wood where the peeling has occurred, fresh sanded cells can fill with the paints pigments.

If a primer was used was it of the proper type for the paint could be another issue. With peeling more on the sunny side paint expansion and primer expansion should be matched.

This info may help you with other possibilities. WHY PAINT PEELS

If the surface prep (sanding) was not achieved then I would scrape and sand off the old paint and abrade the wood, then reapply new. I would not just scrape off the loose and paint over it all for fear of old that remains would peel under the new.