Paving flush with bifold doors, drainage issue

[sunshinyday80]

We're having our decking replaced with porcelain paving and would like the paving to sit flush with the threshold of the doors, with the patio falling away from the house. The issue we have is that the bifold doors have little drainage slots on the outside of the base of the threshold, on top of the cill, which means that presumably we can't have the paving tiles fitted flush, and they would therefore need to butt up against the cill giving us a small step and a less clean look/finish than we had hoped for. I've attached a photo to show the door drainage (apologies for how dirty it is, we've just removed the decking and haven't cleaned properly yet). You can see where the water drains into the hole and then out through the underside of the capped part. Has anyone got any suggestions or have had similar and how have you overcome the problem?

Do you mean you want the paving to be laid so that the surface would be above the drainage hole?

...to the red line?

I'll add the image this time!

Yes, pretty much where your line is, although maybe a few mm lower due to height of tiles

i would be worried about the rain running into your house if everything Wallis exactly level, unless I’ve misunderstood what you’re trying to do? Could you have a drainage channel with a grid over it between the door and the slabs?

No it's not all exactly level, there is still about an inch height at least from the height we'd like the paving and the interior floor (can't really see it clearly from the photos, sorry). If we put in a drainage channel with a grid, how would it allow the water from those drainage slots to get into the channel? I understand how it would collect run off from above, but wasn't sure if any of these drainage solutions would be open on the side that touches the house, if that makes sense?

Depending on how thick the tiles are, you could lay them to the level you want and leave the drainage holes open with a drainage pipe through the grout or sand that is under the slabs that outfalls at the edge of the patio. However, you could find it difficult to clean them out as you are supposed to do from time to time.

A threshold drain is basically a U shape channel with a slotted lid on top. If you got a plastic one you could cut holes in the side that line up with the drainage outlet holes.

My dd has a thin drainage channel - no more than couple of cms - between the paving and her bifolds. Isn’t that the usual thing? She never has water coming in.

I've done a diagram. You could have the slotted top on the threshold drain which would make it easier to clean. Obviously the height of the drain and the thickness of the slabs would have to be suitable for this layout.

Thanks. I'm not sure that would work unfortunately as the height from the top of the cill to the outer door track is only just more than one tile height, so no space for the drain underneath.

Looks like you'll need to put a threshold drain across with the grid flush with the tiles. Can you take the sill out?

You really need the correct doors and frame for this type of threshold. Your existing doors are built to have a step up. You may be able to do the grid design if the depth of the channel is below the drainage holes of your sill. But really you are trying to retrofit something that just wasn’t meant to be. I’ve added a photo but may not post immediately until reviewed. You may also need building control approval for this type of drainage. It was refused in our case (and it was a new extension so everything was new).

Thanks. Yes we're realising now that the design of our doors is quite old and doesn't work with what we want to do. We don't even need it flush, as it's already a couple of inches step down, we're just trying to avoid it being a deeper step down and also wondering how to join the paving to the bottom of the cill. The paver is suggesting we have a land drain under the sill topped up with shingle. But I'm not sure about having shingle so close to the bifolds as it'll get kicked up and go in the tracks etc. Would we need a gap between the cill and the paving for drainage?