Water seeping through walls?

[Rory Scarlett]

Hello...

Over the past few months we have had a growing area of dark patches on our external north facing wall. The obvious thought must be water seeping through the walls and plaster.

On the landing there are large patches which seem to be growing. On the stairs up to the loft conversion there are hair-line cracks in the plaster with what looks like damp patches emerging.

The wall is solid brick with render outside. We have very recently had external insulation and render installed, however this issue started months before this was installed so I do not believe the insulation is the issue. Previous the house was rendered which was not obviously cracked or blown.

There are no water pipes in the walls and the north wall is generally the more sheltered side of the house from prevailing weather. There is a connected garage on that side of the house with a flat roof which tends to drain fairly well.

Any ideas.

 

[Jurassicspark]

Looks like condensation and mould. You need to improve ventilation and reduce humidity.

 

[Ivor Windybottom]

Get a dehumidifier. Put it in one affected room and keep the door shut. If the damp goes away then it's coming from you, not from outside. As you have solid walls, running a dehumidifier at least now and then is possibly just reality.

Do you have decent extractors in your bathroom(s) and over the kitchen hob?

Do you dry laundry by hanging it on racks in the house? You definitely shouldn't with solid walls.

 

[Ivor Windybottom]

One example (of many)...

Wessex Dehumidifier

Steam or condensation won't be a problem around the home with this 12L dehumidifier to call upon. It's perfect for room sizes from 15-25m² and features a choice of three power modes along with a 12-hour timer.Need to dry clothes? Simply switch the dehumidifier to its Laundry mode and direct it...

www.toolstation.com

 

[Rory Scarlett]

We have a dehumidifier which we use to great success in the bathroom. This problem is the hall, stairs and landing so a huge volume.

 

[Ivor Windybottom]

I mean mostly as a test - if a dehumidifier makes the problem go away then it points the finger at you rather than the walls.

Your bathroom should have an extractor, with an over-run timer and a 10mm gap under the door to feed air for extraction.

 

[noseall]

We have a dehumidifier which we use to great success in the bathroom. This problem is the hall, stairs and landing so a huge volume.

The walls need insulating.

 

[Rory Scarlett]

We've just had exterior insulation fitted which has render on top. I'm hoping it will help.

 

[Jurassicspark]

. I'm hoping it will help.

Not on a very chilly day!

You should get a humidity meter and try reducing it.

 

[RonnieE]

Take a look at this guide to mould on walls, it has some handy information as to the cause and how to stop it.