Diagnosing a back door leak

[sirduke]

I've got an issue with a leaking back door and could do with some advice.

The main signs of a leak are the swollen skirting board either side of our south facing back door as can be seen on the attached photograph. We had the same leak in the past and it got resolved by doing something internally we think. About 2 years ago we had the flooring replaced from a quick-step laminate to karndean glue down vinyl tiles and now the skirting boards are swelling up again.

We've had someone in to look at it and after ensuring all was sealed outside, and the problem was still there, he has come to the conclusion that there is probably a problem with some sort of tray in the brickwork above the door which is supposed to drain or catch any rainfall hitting the outside wall. The proposal is to coat the brickwork with waterproofing to stop water getting in to the bricks and this tray above the door which he thinks has a problem, and it's easier and cheaper to do this.

I know nothing about house construction and am wondering whether this is the right course of action, or whether there is anything simpler that can be done. Just curious as to why this issue has arisen again after the vinyl tiles were laid and the skirtings replaced. One theory is that water could be coming up from below, and that because the skirting has no gap between it and the flooring, that the skirting is sucking up the moisture. Could it be anything to do with the way the flooring is now fitted up to the door.

Any thoughts would be appreciated.

S

 

[sirduke]

Sorry forgot the images.

 

[Ivor Windybottom]

I'd get someone to spray the hose at the door from outside while looking at the inside before coming up with any theories. It may just be getting past the door, if so you don't need any special science other than adjusting it.

Beyond that take the two bits of skirting off and see what's there.

If there's an issue with the wall then it needs fixing, not painting with magic solution.

The flooring may be entirely coincidence.

 

[sirduke]

I'd get someone to spray the hose at the door from outside while looking at the inside before coming up with any theories. It may just be getting past the door, if so you don't need any special science other than adjusting it.

Beyond that take the two bits of skirting off and see what's there.

If there's an issue with the wall then it needs fixing, not painting with magic solution.

The flooring may be entirely coincidence.

Thank you. I had thought of spraying water around starting at the bottom and working my way up when I woke up this morning. I think I may have a go with this as it seems a sensible approach.

 

[Ivor Windybottom]

Don't open the door at any point while testing, as soon as you do you ruin all evidence!

A house door won't be as waterproof as a car door, so give it a fair test. Don't jet directly at it, aim to spray it as you would watering a plant.

 

[Ivor Windybottom]

You should be able to see whether the outer seal is getting compressed when closed from the outside before you spray anything.

 

[Alec_t]

Are there any drainage holes in the threshold channels?

 

[Ivor Windybottom]

We had a door a lot like this, with the metal low threshold. We regularly got drips from under it, I thought the water got carried under by capillary action - they don't seal very well at all, nothing like as good as the ones with the full trip-hazard frame under.

Testing will find out though.

 

[sirduke]

Ok I've found out where it is. I've taken the skirting boards off and sprinkled water no more than a foot, so it's not coming down from above, and dound it's dribbling in from behind where the skirting board was on the right hand side. Don't know if you can make it out on the image but it seems to dribble off the broken end of what I think is black dpc. So it looks like it's coming in from somewhere around the door step.

@Alec_t the drainage holes were unblocked a few months ago and the channel is clear of water. Seems like the water is going under the door step and flowing along the dpc and coming out where it's broken.

So now to work out how to fix it.

 

[Ivor Windybottom]

Good stuff, can't beat a bit of science.

Capillary action can do some weird things. A narrow gap will suck water in.

 

[Ivor Windybottom]

It's possible that the water was finding its way down the edge of the old flooring, the new flooring has been shoved in far enough to catch it.

Mystery solved!

 

[sirduke]

It's possible that the water was finding its way down the edge of the old flooring, the new flooring has been shoved in far enough to catch it.

Mystery solved!

That's a good point. Just need to work out whether to try and find out where the water is coming in from the outside, or just seal along the inside, or just at that point.

 

[Ivor Windybottom]

Definitely the outside!

(after it's dried out)