Door gap near bottom lock side

[Arctic_Simon]

I have recently discovered my rear door is leaking. I thought it could be down to the seals on the threshold so i replaced these. The picture below shows a gap where the door doesn't touch the seal near the bottom lock side. I have tried adjusting the strike plates, but these just make the door harder to close and doesn't seal the gap either. Any suggestions on what i can do? Thanks in advance.

 

[crank39]

Your door is warped because it's grey and has absorbed a lot of heat, you can see that in the way it's faded. If you stand on a chair and look down the edge of the door top to bottom you will see the bow. It's recommended with most doors that aren't white that you should always lift the handle up to engage the hooks rather than leaving it just on latch, this helps keep the door straight. As it is now if you've adjusted the striker plates all you can is cut the gasket off and replace for a slightly thicker one

 

[Arctic_Simon]

Thanks for your reply crank39. Not what i wanted to hear but feared it may be. The back garden is south facing so gets the sun all day mostly (when it's out). I will look down the door when i get back home and look into ordering a thicker gasket for now.

 

[Arctic_Simon]

Update for this one. Got a fatter gasket and fitted today. Doors harder to close but gap seems to seal now. Checked after rain and water still in threshold. I think i need to reseal the deflector, i saw drops going behind.