Damp damaging scotia

[Spiritlisa]

Advertisement

Puzzles
Talk AIBU?
AIBU?
Follow topic
MNHQ: Our new mobile apps are out now!
Unwatch
Share
Moisture damaging scotia
4 replies

Spiritlisa · 01/05/2025 16:30
I have reposted this as it somehow ended up in the aibu thread and I would like more advice, so hoping to get it here.

I have had a problem with my scotia in the front room. The pictures attached show what the issue is. The wall is below a bay window - it is an external wall at the front of the house. I have had the wall checked for damp by a special and there are no signs of damp in the walls. The same has happened on an area in another room though not by an external wall, but by the wall next to the fireplace. I know a builder who is at an absolute loss as to what the issue is. I've even had slugs coming under the scotia in the front room, hence salt appearing in one of the photos. This started a couple of years ago and I thought it was sorted as I had someone fix the drain in the front garden as we thought that might have been the cause, but the drain is fine and not on the same side as the most recent damage (the first photo). There is also some damage to the join in the laminate flooring aa can be seen in the second photo. Does anyone have any ideas? Also appealing to @pigletjohn if he is around.

I have no idea about DIY but if you want lots of people to click I’d repost in AIBU with the title “Help- slugs are coming into my living room!” and that will get you loads more views. I had never even heard of “scotia”- thought it was a typo for sofa. Only clicked to see if it was meant to be sofa.

Can you take some pictures of the outside of the wall please? How old is the house and can you see where the damp proof course course is on the outside wall? Also pictures of any guttering of pipework outside nearby would be helpful.

Thank you so much for this. I hardly post on here so need all the advise I can get. At least you know what a scotia is now 😊.

I have attached some pictures
of the outside wall as much as I can as there are bins in the way. The house is Victorian. I know weeding needs to be done as well as a tidy up, but that is all pretty recent . Yesterday I removed most of the worst damaged scotia and it was completely dry so I think that was damaged from a while back, but it was an obscured area so it might have been like that for a while. The slugs are from the corner on the opposite side to the gutter and drain.

I've also attached a picture of some scotia in another room in the house where the same thing has happened, but this is on the left hand side of the fireplace in the other room and not next to an external wall, so even if it was the drain or damp proof course, it wouldn't explain why this one is also the same.

Thank you so much for taking time to look at this. I am really grateful.

It looks like part of the air brick is being covered by your paving. If you look at the difference in floor level where the nearest doorway is, do you think the air brick is under where the internal floor is?

Is the wall rendered but only under the window?

My current guess is that the external ground level is breaching the damp proof membrane and that someone has tanked the inside and rendered the outside to hide the problem and the damp is only able to get through where the Scotia is.

To be honest, I suspected the covered air bricks were the problem. The paving was done in 2018 and I had no idea about such things and the person just paved the front with left over slabs that he was using for the back garden. So the only solution is to dig up the paving? I think i was in denial. It doesn't explain the same thing happening in scotia in the other room though.

Again, thank you.

It's only a guess at the moment. Where else is the Scotia issue and how near the bay window is it?

How long have you lived in the house and has it ever had any damp issues?

The other scotia issue is in our sitting room on the left side of the fireplace. It is in a completely different room to the bay window and not next an external wall. The rest of the scotia in the room is unaffected. I've lived here since 2008. The laminate flooring was laid in 2017. I don't think it is all recent - but the latest one definitely is.

Is the possibly damp wall in the living room shared with the room with the bay in?

Have you had either room replastered since you moved in and did you put the render on the bay window?

I've drawn a very basic picture: the criss cross lines indicate where the problem is.

I would start by improving the sub floor ventilation by getting a builder to put a couple of subfloor vents in, like the air brick in the first picture. They might be able to replace the one which is already there and add one to the other side of the bay. If the back wall of the living room is external I would get 2 put in there too. If you are lucky that will fix it.

They might have to cut some of the paving away at the front to get them at the right level.

Thank you for both pieces of advice. The kitchen is on the other side of the living room so wouldn't be able to put a vent there. I will investigate the airbricks.

Thank you so much.

Is it made of MDF? I also wonder if the floor has been mopped. I'm just guessing really. MDF is fairly poor there especially if it gets wet.

The DPC is usually at the height of the top of the airbrick. So you have 75mm from ground level to DPC.
However you need a minimum of 150mm and for old houses with solid walls, better 225mm between ground level and dpc.
So you need to lower that ground level. Easy job for any handyman or builder. You only need a channel really, 150mm wide should do it. The brickwork will take months to dry out.

I totally agree with @HellsBalls lowering the ground level at the same time is a good idea. Although I have seen airbricks put in above a damp proof course before! Probably unlikely in your house.

Thank you for responding. I have no idea what it is made of actually. A builder did tell me that the quality wasn't great though. I've never mopped the laminate flooring.

@HellsBalls @Geneticsbunny Thank you both so much. I think I need to find another builder who is willing to do the work as my one is adamant that it isn't the airbricks.

Thank you both. Still not sure about the scotia in the other room though 🤔.

The airbricks might not help but it is relatively cheap and is a reasonable, not too destructive stating point.