Blocking gap beneath upvc door

I'd be tempted to use the uPVC board sold for roofline work. Soffit or Fascia capping board to fill in the gap. Thinnest is about 10mm.

From the first picture I thought it was a misfitting door rather than a dirty great gap between the floor and the base of the window frame!

I would be tempted to fill the gap with cement or similar and cover with pvcu trim. E.g.

there is a frame sealant especially for exterior pvc use

I would just get a piece of upvc trim such as one of the products here

Regards

expanding foam could also be used but I am not personally a fan of it as I always seem to put too much in and then spend agess tidying it up

Regards

The cans are horrid - its worth getting a proper gun and low expansion foam. The low ex stuff can be hard to get, so you can use the plasterboard fixing foam instead (which is better mechanically). But probably not work getting a gun for one tiny job. Foaming round windows with high ex foam and a can is, well, hilarious. Simon.

Thanks for the link. That looks like just the sort of thing I need to cover the face of the gap once I've filled the gap itself with something.

frame!

And with the title as well...

Agreed what ever goes into that gap needs to be good in compression. One shouldn't tread on a threshold but people do and being plastic frame it doesn't have much strength, it needs to be properly supported.

As there is a draft that imples a hole through to the outside, before sealing up the inside make sure the outside is water tight. Check that there is something underneath the frame on the outside, installers seem to "forget" that bit quite often.

Yes, the gap goes all the way through to the outside.

I had that problem when we bought this house, it has three outward opening UPVC doors and all of them had gaps under them. I solved the problem with these.

Mike