prime/seal door frame casing before plastering?

[swilli88]

Hi guys, Just wondering if it's a good idea or pointless to prime paint a door lining/casing in situ before plastering around it to try and block moisture getting into the frame and possibly having it swell as a result?

is this a thing? Overthinking?

 

[dontbelieveawordofit]

if theres a gap at the head or base of the frame/liner for it to expand then it should be fine. if not , then there is a possibility there may be a small amount of bowing due to expansion from the water in your plaster.
you could duct tape the back and exposed edge then trim it off when its dry.
its usually not an issue unless the frame is jammed in

 

[lostinthelight]

Personally I dont think your over thinking it. Timber today seems to absorb moisture so quickly I always at least prime door linings architrave ,skirting both sides before fitting.
Door linings where I have to skim up to get extra layers so they dont swell , . I make sure to scrape plaster buildup off the lining edge between coats , something Ive noticed some so called pros can't be arsed to do.