Conflicting damp advice

[LeavesOffTheCactus]

Hi all,

I’ve recently moved into a Victorian end terrace and the survey highlighted “multi factorial damp issues”. They are caused by…

• guttering that overflows down the walls - we are going to replace these
• “rising damp”. I know that rising damp is not a thing but what IS causing it? Just the guttering?

Outside there is a cement plinth that is very high up the wall. Could that be exacerbating the problem? Can I have it removed? Why hasn’t the damp surveyor recommended this if so?

Attached is a picture of where damp was found (red lines) as you can see it’s basically the whole ground floor.

I’m not too bothered by anything from the loo to the conservatory as I’m going to have that section of the house reconfigured when I have the side return extension done, but I do want to protect the timbers and skirting boards in the living room so really want to tackle the damp. Any suggestions welcome!

Thanks!

A victorian house is pretty sure to have leaking pipes and leaking drains and leaking gutters.

you already found the leaking gutters

it probably also has earth or paving above the DPC and may also have blocked airbricks.

Do not allow anyone who sells silicone injections near your house.

p.s.

you are going to have to lift some floorboards and have a look and a sniff

if the water supply pipe runs under the hall floor to the kitchen, it is probably leaking.

The hearths are probably damp because the hearthstone is placed on a slab with no dpm. All chimney flues need to be ventilated top and bottom.

The cement plinth will have been added in a futile and counterproductive attempt to hide damp at the bottom of the walls. It will have the effect of bridging the DPC and encouraging water to rise up the wall by capillary action. It has the secondary effect of covering up the bricks to prevent water evaporating off their faces, thus keeping them damp.

Damp- could be that your house has no damp course installed or that it has failed. This will cause damp rising aprrox a metre above your floor level. Rising damo is definitely a thing, and an expensive one to fix.

The people above are suggesting other possible causes. Damp is horrible and uneasy to identify and expensive to fix. I have lots of experience

IME Victorian houses do have DPCs, almost always slate. They were made compulsory in 1875 though some were not very good. Many of the worst Victorian houses in cities fell down in WW2 if a bomb fell nearby.

IME water in a house always has a source; either rain, or plumbing.

Though I do have a neighbour whose cellar used to flood at high tides.

I do not want to inject a chemical DPC as has been suggested by the people that came round.

The house is approx. 1885 so it should have a DPC. I’m going to have a proper look for this though the plinth is probably obscuring it and rendering it useless.

@PigletJohn How do I find a damp specialist who will carry out proper investigations for me and actually sort the problem rather than suggesting chemical DPC?

Do you think I should have the cement plinth removed? This would be major as it’s VERY high - about 1.5m high if I recall correctly. Is it possible/a good idea?

To the rear of the house there is a step that is bridging the DPC so I think the bridging issue is a very likely contender. Will send pics of the outside of the house tomorrow.

Have you got a lead water supply? If yes replace it as lead leaks over time.
A drain survey may find old drains. I had the drains replaced with plastic in my house because I was building an extension and it solved a lot of damp. There were a few disused drained still connected to the main drain.
Cement attracts damp. Where you have exterior walls you can dig french drains and they will help.
There are some good books on damp and worth reading up.

A genuine Chartered Surveyor should be able to identify the common problems. There may also be a "Victorian Society" or a "Historic Ambridge" in your area with a particular interest in such things.

I suupose local facebook would track them down. Local libraries used to have such organisations on their noticeboard.

If you can see the DPC (it is often visible beside or under a doorstep) follow it round the house, with a chalk line where it is not readily vible. Unless you are on a hill it is pretty certain to be at the same height all round the house. it will be two bricks (nine inches, 180mm) above where ground level used to be when the house was built, and you should reduce paving or flowerbeds if they have been built higher. Best is to also dig a trench to encourage drainage, and fill it with cobbles or large pebbles, which do not permit water to rise by capillary action since the gaps are too large. The stones will prevent you falling into the trench. This will also expose the brickwork and show you if the hidden mortar is in good condition. Exposed brickwork will lose water by evaporation, making the wall drier.

Also look at your neighbours' similar houses to see which have been sympathetically restored.

You can yourself test the incoming water main for leakage under the house. You need an assistant, an engineers stethoscope, and to know where the outdoor stopcock or water meter is (usually under the pavement at the front, but terraced houses may have a service lane or alley behind them)

I can strongly recommend Andrew Mitchell who is self employed at Avad Consulting. He is excellent on heritage /traditional buildings and their issues and how to deal with them. He doesn't have a website, he is too busy to need one and if he's not able to help he'll likely be able to recommend someone who can.
[email protected]
Meanwhile do some reading on the topic on spab.org.uk so you can get your head round the issue as whoever you engage to help you want your bullshit radar well calibrated.

Look in the advice section