Condensation or rising damp?

[Pappa]

Hi guys

 

120 year old Victorian Terrace house in Lancashire, England...

I've got some damp on the ground floor front room wall. This is an external wall with a 50mm cavity in between. This wall goes down all the way to the foundation underneath the basement.

 

The skirting board has been removed and the bricks and mortar are wet. This is corroborated by a moisture meter.

 

I can see someone has attempted to install a chemical DPC from the drill holes in the brick. Am I right in thinking this is quite an old system as modern chemical DPC is inserted at the mortar line?

 

How can i differentiate whether this is rising damp or condensation? It might also be penetrating damp as I had some vicious Ivy that was growing through the uPVC window frames. The Ivy was removed about 1 month ago.

 

Thanks in advance

 

Pappa

 

 

[Mike]

31 minutes ago, Pappa said:

How can i differentiate whether this is rising damp or condensation?

Damp normally evaporates from a wall within 2 or 3 brick courses above the outside ground level. It doesn't 'rise' unless there's impervious render or the like preventing the evaporation.

 

Could be penetrating damp, could be condensation.

 

Photos inside and out may help, if that doesn't answer the question.

 

36 minutes ago, Pappa said:

someone has attempted to install a chemical DPC

Chemical DPCs are normally not needed.

[ProDave]

I would be VERY surprised if any wall is cold enough at this time of year for condensation to form.  Most likely some form of damp.  I would be wanting to lift some floorboards to see what the wall and sub floor space is like in that region.

[scottishjohn]

3 hours ago, Pappa said:

It might also be penetrating damp as I had some vicious Ivy that was growing through the uPVC window frames. The Ivy was removed about 1 month ago

If it is and has been tracking water in for some time  it will take a lot more than a month to dry out once you have sorted the problem 

ask anybody who has had the house flooded how long it takes for it to dry out

[Gone West]

13 hours ago, Pappa said:

120 year old Victorian Terrace house in Lancashire, England...

I've got some damp on the ground floor front room wall. This is an external wall with a 50mm cavity in between.

Many years ago I had a Victorian semi built in 1900 which had 2" cavity walls. It had a slate DPC and had a damp problem in one area. The problem was due to the soil level being above the slate DPC. Ignore the chemical DPC and look for the level of the original DPC to see if there is a problem with the soil level.

[MJNewton]

You can tape some foil to the wall (well sealed around the edge) and see which side the moisture appears. If it is the exposed room-facing side it is likely condensation, if it is on the wall-facing side it's coming from/through there. 

Edited July 31 by MJNewton

[Pocster]

2 hours ago, MJNewton said:

You can tape some foil to the wall (well sealed around the edge) and see which side the moisture appears. If it is the exposed room-facing side it is likely condensation, if it is on the wall-facing side it's coming from/through there. 

Thats a neat trick 👍

[Dave Jones]

On 31/07/2024 at 09:15, MJNewton said:

You can tape some foil to the wall (well sealed around the edge) and see which side the moisture appears. If it is the exposed room-facing side it is likely condensation, if it is on the wall-facing side it's coming from/through there. 

 

wouldn't this just be showing where the dew point is ? different days cold/hot could give you opposite results ?