Exterior Azek PVC shutters -- gluing redwood appliques to Azek: problem?

[Carlos Arteta]

I am building exterior shutters with (1-inch thick) Azek PVC for durability. I will soon paint them with Sherwin Williams Duration exterior acrylic (dark color with Vinyl Safe tehcnology to minimize expansion/contraction); they say Azek doesn't need priming. I have decided to attach some small appliques (about 2-3 inches wide/long) which repeat the same motives elsewhere in the house and will brign visual consistency). For a number of reasons, the appliques will be made or (3/8" or 1/2" thick) redwood, with oil primer and the same Duration topcoat. Given how the project is going, I will likely paint the shutters, then paint the appliques, and then attach them to the shutters.

Question: does the potential difference in expansion/contraction rates between Azek and redwood matter? What should I do to attach the appliques -- glue or screws (or both)? If gleu, is it OK to attach both surfaces after painting, or is it better to attach them before painting (but, of course, after priming the appliques).

My intuition tells me that, given they are small, it is OK to just paint both surfaces before attachment, that glue would suffice, and that the expansion/contraction shouldn't be a problem, given the size of the appliques. But I just want to double-check. Thanks

[Don Jarvie]

I have quite a bit of Azek around my house as trim and haven't noticed an issue with expansion/contraction that was at least noticible to the eye. I used finish nails and chaulked over the holes and haven't see any disturbances to the chaulk.

You might try liquid nails and finsh nails then paint everything. The expanison will probably come from the redwood so the liquid nails may offer a bit more flexibility than glue and a few small finish nails to keep them in place.

Azek takes paint great. I painted my trim 4 years ago and haven't had to touch it yet. Very nice product to work with.