Mark wrote:
My flat has one of those PVC (plastic?) front doors set into the (old) wooden
frame. Although it's all pretty secure, there are cracks/gaps which were
probably created when the new door was put in, but never rectified.

Is there any widely-available sealant I can use to cover these up - i.e.
something that will adhere well to PVC/wood/paint?

Cheers ... Mark


Try acryclic frame sealer.
It takes paint, which silicone doesn't.

Not as rubbery as silicone, so make sure frame is well fixed in place first.