Onoff

12.5mm Knauf Aquapanel here then Aquaseal tanking membrane over that in the wet room corner.

That looks fantastic! ???

I see what you did there! Needs work.

This is where I get bored and it starts to go slow. Doing the hardcore, got bloody great lumps I'm breaking up with a club hammer to get sort of level before the sand blind. Boring as Hell. It'd be much easier if smaller bits to start with. I've about 7 or 8 jumbo bags of assorted rubbly crap. Debating hiring a crusher one weekend to turn into a nice pile or ready to use Type 1, 2 esque. Would be handy when I do my drive. Blinded it with some all in one. Went over with the little Evolution electric whacker (the 5kN one). I'll round up a load of small sand, ballast etc plastic bags to lay down before the DPM as a bit of protection against some of the sharper stones: Still debating casting the dwarf wall...

Pronounced "vit"?

5 Star Grout?

Ponal isn't German for "pony" is it?

It wasn't out of date was it?

Longer than usual though...

I couldn't at the moment anyway.

That was @pocster!

It's still got his goat...

This is a hardwood sill, some abandoned project of mine. The ends of the jams would have tenons on that slotted into the mortices in the sill: A galvanised steel weather strip sits in the groove. You can see how traditionally the weather strip extends through the jams. The weather strip provides full width protection against driving rain. With our old, original back door here the hardwood sill was so worn and weathered, I folded up a bit of aluminium sheet to go over it. Painted with some special metals primer is was on there ages before I fitted the uPVC door and sill. It butted up against the weather strip and was shaped to go round the jams, the full width of the rotten sill and hooked over the front. Still got the folded ali bit:

Rotten / worn hardwood sills are replaced quite often, leaving the jams in place if good though more often than not at least the bottoms if the jams will need replacing using say a scarf joint. It's proper, old fashioned chippy stuff. Guessing what it the sole plate of your wall is currently your "sill"? You could cut that out and drop in a bit of hardwood sill. Ideally though the sill ends go under the jams. You have what you have so have to work around/adapt, lots of options! Your dad sounds like a man who'll figure it.

I've decided on my mix. Was waiting for SWMBO and the kids to lay out their panels. SWMBO had a go and imo it looks alright (panel No 4) but I don't think it'll work as there's little depth to the stones she's chosen. Thinking these shallow stones will maybe fall out over time?

He was I believe schooled in Kent, God's own county.

Usually your hardwood sill is put in as part of the door frame. Traditionally the jams fit into the sill as tenons. The galvanised weatherstrip extends into the jams. Like this. Why not fold up a bit of aluminium sheet to go over the softwood "sill" that's there, then add a modern, all singing threshold strip on top of that?

I have my Skip Diving badge!

You really want a hardwood sill there as it'll take lots of weather and abuse. You could graft a hardwood bit on the front I suppose.....

You can get them combined as a threshold bit then a weatherstrip: https://www.wickes.co.uk/Wickes-Threshold-and-Rain-Deflector-White-838-mm/p/203002 Or put a traditional wooden bit on the door to oversail a modern, sealing threshold. Search the Stormguard stuff:

Yes. Because too you have a grooved front you might want to silicone a weatherstrip on above something like this below: https://www.google.com/search?q=inward+opening+door+threshold&client=ms-android-motorola&prmd=sinxv&sxsrf=AOaemvJTOQkB52qwZ86TFu9Nd1m7j6ziKw:1632083566354&source=lnms&tbm=isch&sa=X&ved=2ahUKEwiz2dyJ8YvzAhUdDmMBHWIGDykQ_AUoAnoECAIQAg&biw=360&bih=512&dpr=2

A few on here have Bora downdraft extractors I think. Search "Bora".

Well you have been busy...