subfloor height issue versus upvc door

[mattbakermk2]

Hi all,

Hope some one can help/shed some light for me...

Background:
Hallway area 70s build house. Concrete floor with screed top later c. 40-50mm thick. Was tiled. Had new UPVC front door fitted with original floor in place, used to open and clear floor fine, although there was no space for a mat under the door (frustrating). As part of renovation work, tile floor has been lifted exposing what seems a pretty good condition screed - to the eye at least it looks flat anyway. Checked total clearance with front door shut, and ordered an engineered oak floor (18mm boards) + 5.5 insulation boards to go under and even out any surface imperfections. This fits fine with the front door in closed position, and should be only marginally deeper than the original tile floor.

Current Status/Issues
Realised last night that as the door swings through it's opening path, the depth to the current screed floor drops - to the point where the viable gap is only just about 5mm - i.e. we'd struggle to even get carpet down now! Whilst I could lay wood floor up to a point and then fit a recessed mat in the opening, it would create a stepped edge, and the mat would have to much larger than we'd like, so this isn't a viable option.

So What Can I do, and what's happened?
Has my floor swelled - exposure to more moisture content?
Has my door dropped?
I can't understand how the difference is suddenly so obvious - there's no way the original tiling would fit under the door now!
I can't plane down a UPVC door...
I'm reluctant to dig up the existing screed and redo it - and it may not help as the current level couldn't be dropped much if at all due to the water pipes buried within it pretty close to surface already.
Removing and refitting the door higher up would risk destroying the completed and decorated work done both inside and outside? (the existing door would be limited by the blocks and stud work surrounding the frame anyway)

What would you recommend I consider doing?

Stuck and stressed!!!

 

[crazydaze]

A Matwell would be far and away the easiest solution, otherwise it's mess with the subfloor or perhaps replace the front door and frame?

 

[mattbakermk2]

update - having checked the real state of the existing floor in terms of level, there is a definite 'hump' under the section where the door opens, i.e. you can sit a level over this section and rock it an all directions around this part. Not by much, but looks to be enough to cause the issues I'm facing.

So now thinking that my best option will indeed be to dig up the screed and replace at a slightly lower level as far as my water pipes allow.

Couple of question that I couldn't see covered in the stickies:

1. is the Wickes deep fill self leveller an ok product to use, or should I avoid like the plague - it sounds like an easy to use DIY solution to replacing up to a 50mm depth with a self leveller all-in-one product
2. Is it viable to only dig up part of the floor, or will I need to dig the whole area up - my problem zone is about 2 square meters at one end of the hall, but that's not to say the rest is 100% perfect - just that there's no doors to worry about on the rest - and as previously advised it all looks ok to the naked eye, but not sure what tolerance I can get away with when the wood floor eventually goes down.

The floor that will eventually go down is an engineered wood floor, I was planning on laying as a floating floor...

Any advice appreciated.