Not for the first time have I seen this, though it is rare. Linacre Locksmiths were called out to replace a full length multipoint locking strip today by a customer who had complained that her door had ‘dropped’ and was difficult to lock for a while. Over time this had meant the mechanism was getting forced harder and harder to operate. The lock eventually failed. I undid screws from top downwards and when I was within 2 feet from the bottom, on removing the screw a jet of water shot out.
This jet continued for about 5 mins, then as I work down to remove the lower screws more water came out. Must have been a gallon in the door. No wonder it had dropped with all that extra weight.
This can happen with outward opening doors, especially old ones, as rain water can seep into the old shrunken rubber seals and enter door cavity. Normally there are drain holes at the bottom of the doors to allow this water to escape but over time they get clogged with dirt, moss etc and bung the holes up.
So if your door feels ‘heavy’, or if it seems to have dropped excessively then maybe yours too has water trapped. Check any visible drainage holes and clear out any debris. That includes drainage holes in the threshold (sill) too. Of course, other causes can result in doors misaligning and locking points not engaging with their keeps on the frame correctly, leading to stress damage.
Just give us a call to resolve and lock issues you have, and hopefully prevent an expensive replacement of parts.