Rising damp?

Hi

Apologies in advance for essay.

My lounge had a new concrete floor laid around 8 weeks ago. Damp proof membrane was put down and builder's pal told me he tucked it up under skirting boards (originals were kept in place).

Before floor was laid there was a small damp patch on floor next to interior wall which we thought was from a leak from external wall above (adjacent kitchen has watermarks at top of wall, same area). A crack on this external wall was re-rendered when floor laid. Wall is original stone wall circa 1900 I think, so no damp course and lime mortar as far as I know.

Shortly after new floor was laid there was heavy rain and I spotted a small water patch above skirting, same area, plus salt crystals. It subsequently dried and has been fine so assumed it was residual. We've just had heavy rain again and a new small damp patch has appeared on floor below skirting, just along from original patch.

Builder thinks it's rising damp...

If membrane was edged to skirting board, can damp come up in front of skirting?

Is it possible water could trickle through inside of stone wall and appear only at bottom, so it may still be external leak? Builder thinks there would be water mark higher up if leak was above.

Cupboard in pic is on outside wall. No sign of water on this outside wall, or anywhere else.

Any expert ideas please?

 

Thanks both for taking time to reply. Some more photos attached.

It's hard to get good pics sorry as room is quite dark. The area that looks dark in original pic is my shadow I think. Hopefully these give a better overall idea though.

Alcove cupboards are against outer wall. Damp spot is by interior wall.
High ceiling of adjoining kitchen wall with damp stain - staining has been there years as haven't repainted after outside wall was re-rendered 4 years ago. Just got up there and again hard to tell but I think it's a bit damp up there. I've marked around darker area so I can judge over next few days.
Outside pic shows where last render has been cut out and re-done again!

This home of mine costs me a small fortune.

There's also a pic of lounge ceiling corner which shows a darker area but I'm finding it hard to judge if that's just shadow.

There's no sign of damp in bedroom but 2 years ago I had 2×false interior walls put in for insulation of outer walls. Chimney wall has a vent.

If water is getting in at top of kitchen, is it possible it could only show at base of adjoining wall? Stone wall is 45cm thick.

Thanks

Sarah

 

Sorry hit send by mistake. Here's the other pics.

 

That's the new render. Section was cut out then meshed and re rendered.

 

That was all checked when they did the re render but I'll ask them to have another look. I think this is why builder is so sure it's water coming up, because he can't work out where it could be getting in.

 

Thanks KIAB. Problem is stains etc happened when there def was a leak a while ago so it's hard to tell if water is still coming in now.

Thanks for the advice. You've confirmed that at very least we need to check for leak. Fingers crossed we find it soon!

Enjoy the sunny weekend