Anyone know much about damp ?

[hilbil21]

I was wondering if there's anyone who would be able to help me? I've noticed these marks on our back (external) wall just above the skirting boards. Does it look like rising damp?? Thank you in advance

damp can be for a number of reasons. A good company will do a survey and advise. They dont always suggest you have work done. Sometimes its condensation, chimney ventilation, rubbish over the damp course outside, plaster bridging the damp course behind the skirting or yes rising damp

I think condensation is worth considering first. Does it feel damp to touch and in the morning do water droplets form? Does the black wipe off only to re appear a few days later?
Age of property a factor too.
IF you do get a company in to take a look just be wary if they start on about major works and get more than one company in.

With condensation you can see it glistening in the morning or in cold weather.

I don't think it's condensation, there are never drops and it never feels wet. It's next to a radiator (either side) and under a window. Think will need to get someone in to have a look.

We are hoping to put our house on the market shortly, typical that this appears just now!

Thanks for your help

The house was built in 1939 and marks don't go away when wiped

in that position, may well be caused by a leaking pipe. Is the floor concrete or wood?

Have you got a water meter?

What is on the other side of that wall? (photo please)

Don't invite into your home anybody that sells chemical injections. They will tell you to buy xchemical injections.

A few things you can be certain of with chemical injections

they will not mend leaking pipes

they will not lower high water tables

they will not unblock airbricks

they will not clear overflowing gutters

they will not repair leaking baths.

they will not lower paving or flowerbeds built up against the wall

they will not dry out steamy bathrooms

they will not repair cracked render

they will not seal gappy windowframes

In short, they will not fix any of the common causes of damp.

Hi Pigletjohn

Thank you for your reply. We don't have a water meter (in Scotland). Floor is engineered wood flooring on top of floorboards. Photos are attached of what is on other side of wall. I've also noticed these marks further up and along the same wall.

Thank you for your help

On the outside, that wall looks wet along the bottom, and I don't see any airbricks to ventilate the subfloor void. There appears to be a rainwater downpipe delivering water close to the wet wall, but I can'y see where it goes.

Is the concrete apron original to the house, or a later addition? Pour some water on the apron and see which way it runs. During rain, look and see if water is collecting on the apron, or falling on it from e.g. a gutter.

Walk round your house looking for the dpc. It may be visible near doorways, doorsteps and unrendered brickwork. It will be about two bricks above where ground level used to be when the house was built.

Look at the plaster in that room. Your internal pic looks to me as if the lower part of the wall has been replastered; possibly last time somebody tried to hide the damp.

Look at similar houses in your street for

• airbricks
• drain layout
• height of ground or paving against the wall

Thank you Will find out what I can