In article , "Robert11" wrote:
Live in the Boston area.

Will be having pre-primed Cedar clapboards (the typical horizontal board
type) put up on my house that is being re-modeled.

Contractors, being contractors, I am a bit concerned that the job will run
into the early Fall by the time it is completed, and ready for painting.

Would appreciate opinions on the following:

a. how "safe" is it to leave the clapboards in the pre-primed, Unpainted,
condition thru the winter, and have them painted in the Spring, if necessary?

Not a really good idea. You may have adhesion problems with the topcoat unless
you re-prime them. Certainly you'll want to wash them first.

b. Just out of curiosity, would the answer be any different if they were
not pre-primed, and just the bare Cedar ?

Sure. It turns the answer from "not a really good idea" into "a really bad
idea." Sitting there for months, exposed, the wood is going to get dirty.
Neither paint nor primer sticks well to dirt. It's a lot easier to wash dirt
off of a primed surface than off of bare wood. In addition, there will be much
more weathering of the wood.

Best to paint them before winter. Sherwin-Williams now sells a low-temperature
exterior paint that they claim is OK down to (IIRC) 35 degrees, and other
paint manufacturers probably do too. That would seem to be the way to go.

And if you use unprimed cedar, make sure to use an oil-based primer.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.