How to fix water damage on wall corner?

[dzg]

Hi, we have a hallway wall corner showing some water damage. appears to be rust / salt pimples. It runs nearly the whole way along the wall edge. We had a rising damp specialist in to look at that and other water ingress symptoms, and he couldn't  say for sure where it was coming from, but didnt think it would be rising damp, given how high it reaches.

We have an aircon above, but it isnt used in several years so dont think it is the cause. also we have a downpipe nearby outside, so am wondering if that might be the cause (if blocked pipes somewhere underground).  Hoping someone here might be able to point this in the right direction. thanks

   

[EricL]

Hello @dzg 

Thanks for sharing your question about the water damage on your wall corner. Rising damp quite often appears in large patches and has a uniform way of damaging walls in large sections. The water damage on your wall appears to be very specific and only in that particular location. Theoretically speaking, if water was leaking in that corner, it would at some point appear outside that corner and drip onto your floor. But it looks like there is no water damage to your floor.

Taking these things into consideration, it would be safe to conclude that water is passing inside the wall but not enough that it forces itself outside your wall. If water continues to deteriorate that section of your wall it should be soft and brittle or soft and spongy when pressed. If you are able to, I propose going into your roof cavity and looking at the section of your ceiling and see if water is dripping into that section of your wall.  

Your second option is to remove the corner plastering and doing some inside investigation in the wall to see if you can track down the source of the water. The third option is to engage the services of a leak detection specialist preferably one that offers thermal imaging. They should be able to pinpoint the possible source of the leak.

Let me call on our experienced members @Dave-1, @Nailbag and @AlanM52 for their recommendations.

If you need further assistance, please let us know.  

Eric

[Dave-1]

Good Evening @dzg 

I was just looking at your pics and @EricL tagged me lol 

I am thinking along the same lines as @EricL 's suggestion. Tho I would see if I can push a nail into the plaster around the corner to see if it fits the spongy feeling that he mentions. I am thinking maybe the angled metal corner was in a corroded state at install and its continued rusting, maybe it got wet years ago from the air con unit fitted above and that started the rust which has caused that rough effect on the corner. 

There are no other drip marks/dampness down near the floor? Because you have had a rising damp specialist look at it and they didnt find anything I would be thinking of redoing that corner edge totally. As in remove the metal corner under the plaster, clean it up and install a new piece. At the same time check to see if you can see further instances of decay within the wall.

Dave

[AlanM52]

Hi @dzg,

It's worth the effort to do some more inspections.

When did you first notice that and has it been developing over a period of time?

That is a external wall corner and I have a feeling the water ingress is from above.

Although hardly used can you remove the aircon evaporator cover and check inside to see that all is dry.

Maybe the plumbing out to the compressor is letting water in.

Check the gutter above that area and push back some first row tiles to see that everything is dry.

Water finding it's way under ridge tiles because of dislodged mortar can find it's way down the rafter(s) and into the wall cavity.

Check for chunks of mortar on the roof or in the gutter.

Oh... does that corner have a roof valley.

Whatever the cause as @Dave-1 mentioned that plastering bead will likely need to be replaced so go ahead and remove that...  hopefully some more dots will be connected.

Cheers

[Nailbag]

Hi @dzg 

Its common for the water drain of split system to block up though usually with older system. But there could be a nest or other debris etc. 

First port of call is to get a plumber to inspect the system completely and might as well get it serviced with filters cleaned etc to maximise the opportunity. If nothing found wrong with the system, get them to check roof guttering, flashing and the installation of the system.

Last port of call is a leak detection specialist company. Then the repairs begin.

Nailbag

[MitchellMc]

Hi @dzg,

I just thought I'd mention that the vast majority of the damage appears to be plaster filler that was never sanded back adequately. It's proud of the surface, and I'd say whoever repaired the corner at one stage got sick of sanding and called it a day. There is obviously some moisture in the area, given the rusted corner bead and the delaminating paint at the top of the third image, but I'd say the rest of it is just an unfinished corner repair.

My advice would be to cut out the corner bead, inspect behind it and then redo the corner.

Please let me know if you have any questions.

Mitchell

[dzg]

hi @MitchellMc @Nailbag @AlanM52 @Dave-1 @EricL 

thanks everyone for the review and suggestions.

Plaster damage on corner: yes you are right @MitchellMc , I actually did this a few years ago in a lazy attempt to cover the surface. I will do it better next time, but the real damage i think is the wet symptoms

Aircon: yes we just had the aircon fixed and replaced, and I could see partially into the cavity behind. There wasnt any obvious water damage, although the area above the corner in the picture wasnt visible. The old aircon though did previously have leaks in the piping (the reason we stopped using it).

Outside guttering/roof: see attached new photo for the 2nd floor gutter above (or close to) this ground floor wall. There is some render coming off the wall under the gutter, and I was concerned this could be a cause of some damage below, but it isnt directly above the internal corner shown in first pictures. We are having a roofer around soon to fix some other leaks in the roof, but I havent asked him to fix this. Not sure if it is a roofer or another tradie that would fix this type of thing. but as @Nailbag and @AlanM52 pointed out, maybe this is the cause of what we are seeing internally.

I assume the best place to start now is this render issue up near the gutter.

 

[EricL]

Hello @dzg 

Repairing small, damaged sections such as the one you've shown is always a plus, as it patches any possible entry point for water or moisture. 

Please keep us updated with your progress, we look forward to seeing your wall leak fixed.

Eric