Bifold Door Leaking and Defying Gravity!

1 Aug 2020
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United Kingdom
Hi all! Long term lurker, first time poster here - been using DIYnot forums for many years and always managed to find an answer, alas this one has me stumped so time to create an account and get posting!

We have some bifold doors in our kitchen that occassionaly leak in a very specific place when it rains heavily:

The water isn't running down the inside, it appears to be coming up and over the innermost channel of the threshold (i.e. one without any drainage holes:

I've notice that the inner most channel is filling with water:

I suspect that the brushes are soaking up the water and pulling it up and over the threshold thus creating the gravity defying effect.

I then noticed from the outside that there is a definite gap in the gasket:

So, as a starter for 10, I have ordered a length of gasket to replace the one that is too short, however I would really appreciate any additional advice or opinions.

Thanks all!
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It looks like the water is getting wicked up where the door seal presses against the furry seal.

Is the drainage channel clearing ok? - maybe the drainage holes are blocked.

The seals along the head of the door don't look to be under pressure maybe water is getting in at the top. The head of the door has no head drip so lots of water will run down the brickwork and reach that point.

You could do a hose pipe test to see a bit more -start low down, testing first the cill, then the door seals then the head. Try to replicate rain using a shower setting rather than high pressure jet.
The drainage channel is fine, I poured a jug of water in and saw water coming out 3 holes on the outside, so in theory if the innermost channel fills up, it should spill over into the drainage channel and drain away, but as you said (and I love the word you used to describe the effect) it is being 'wicked' up and over.

If I 'pre-fill' the innermost channel with water and get jiggy with my hose :mrgreen: it only starts to leak when I concentrate on that uppermost part of the door where there is a gap in the seal, hence why I'm starting off by rectifying that.

I'm intrigued by your head drip comment though. Is it possible to retrofit a head drip? A quick google suggests I can.

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just a thought
assuming thats a hinge above the area next time you see the water try touching the bottom face off the hinge
now i am fully expecting it to be dry but stranger things have happened :D

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