Damp on Skirting Board?

[AntonyE]

Hi,

I'm trying to identify what is causing these marks on my skirting board (see picture below) and would appreciate any advice!
-- The skirting boards were changed about 6 months ago. There were no marks on the skirting board then. I don't know if the door frame on the left was buckling.
-- There was a box sitting in front of this area for about 5 months.
-- Then I moved the box and found these marks.
-- I assumed this was water leaking in via the door frame somehow and so put some sealant around the door frame on the outside.
-- No more marks appeared during December (which was pretty wet and cold). So I thought I'd solved it.
-- But then in the last couple of days a new patch appeared which I've circled in red. The rest of the mark really hasn't changed at all. I'm looking at photos of the mark I took a month ago and the outline is pretty much exactly the same.

As I say, I'd assumed that this was water leaking in, but it just seems odd that this new patch has appeared in the middle of the board and the rest of the marks are exactly the same. So I was wondering if there is something else going on?

The post on the left of the picture is a door frame going outside. On the outside there is some decking that is level with the floor. I've never seen under the decking so not sure what it looks like under there. The door frame goes under the decking.

Really appreciate any help/advice!

Thank you,
Antony

 

[blup]

Can you post a picture of the decking. If it's level with the internal floor damp may have bridged the dpc, which is usually - or should be - 150mm lower than floor level.

Blup

 

[tell80]

From what you say about the deck and the pics that you show it looks like you have penetrating damp.
The skirting and the plinth block both show signs of fungal rot.
Most likely that the door frame is also damaged.
The plaster is also showing moisture damage.
If you have a wood floor then closely examine it.
Probe all woodwork with a sharp, pointed tool.

Remove the skirting (cut the paint & sealant with a knife) and plinth block, and then hack off, say, a 600mm square of plaster.
There might be more evident damage in the entranceway - why not post a pic of the threshold?

 

[AntonyE]

Thanks for the responses! I've attached a few pictures showing the overall internal room structure (the damp is to the right of the double door), the threshold (the decking is actually ABOVE the level of the floor), the outside of the wall that is damp, and a close-up looking down the gap between the decking and the wall. If you have any suggestions on whether this looks like penetrating damp or something else and what I can do about it that would be great.

Note that this is a Victorian house (though this bit may be an extension) so some of the construction is likely to be 100+ years old. Also that 6-9 months ago we had the room treated for rising damp (plaster taken away, wall treated, replastered). I'm not sure if the skirting boards are new or the old ones were re-painted and put back.

 

[Koolpc]

Looks like penetrating damp for sure...

 

[AntonyE]

Thanks Koolpc. So my plan is to get someone to remove the decking, reseal the wall from the outside, improve the drainage as needed, and then put new decking in that's probably about 20cm lower. Does that sound like a reasonable plan? Appreciate the help!

 

[tell80]

1. what look like DPC injection holes can be seen on the outside just above the plinth. You dont establish a DPC above the FFL .
2. The injection DPC, FWIW, is useless anyway: based on the info so far, its not rising damp, its penetrating damp caused by the deck.
3. whatever material the plinth is it should be removed and the wall made good.
4. render should finish above the DPC course with a BellCast.
5. so your deck should go min 150mm below any DPC.
6. no "resealing of the wall" is needed.
7. is your floor suspended or solid?
8. what I suggested yesterday in post #3 still stands.

 

[blup]

The plinth or base of the outside wall has been rendered with cement and bitumen paint added, this allows the damp to "bridge" from under the dpc to the wall above and through the wall/door frame, and into the plaster floorboard. But the rain which runs along the decking boards onto the wall is likely the major cause of the penetrating damp.

Blup

 

[AntonyE]

Thanks again tell80 for all the clear advice in #3 and #7. I believe the floor is solid.
And thanks Blup as well.

Just to check regarding the comments on the plinth ... you're saying that the rendering on the plinth should be removed since it's probably allowing damp to bridge from under the DPC to over the DPC?

BTW ... I'll probably get the deck re-done in the spring and once I get the current deck pulled up I'll get someone to take a look at the wall, redo the plinth, and tell80's suggestions from #3 before I get the new deck put in. If you can recommend anyone who does those kind of jobs around North London that'd be great.

 

[miafricker]

The marks on your skirting board could be due to various factors, but it's challenging to pinpoint the exact cause without a physical inspection. Moisture damage seems to be the most obvious reason, which aligns with your initial suspicion. If you want to read more about skirting boards and how they are installed, here is a great article about it https://skirtingsrus.co.uk/blog/joints-used-for-installing-skirting-and-architrave . Hope it helps.