Damp & Mould in a 19th Century Property

[LBoyham]

We have an end terrace which has terrible mould in the kitchen we have pulled off the back of the sink unit and the pipes are wet and water is running off. The mould is around the whole of the kitchen which will now have to be ripped out.

We have mould in the kitchen, bathroom, under the stairs, front bedroom. The tennant is moving out because of the damp. We also have a travelling line on the inner walls in the hall and dining room looks like salt.

We have put trickle vents in have had the property rendered put vents in the walls. We think the heating hasnt been on much and also think condensation has something to do with the problems. Can anyone help please.

 

[fmck]

I think before you do anything you need to be certain what is causing the problem or you will keep throwing money at it.

Sounds like the walls have more that condensation on them if salt is coming through. If it is condensation you need to paint your walls with a barrier paint. Emulsion paints are like putting soil on your walls, add water and guess what happens. A gloss paint (cheap) or egg shell would do it. Crown do bathroom paints for this purpose.

If the damp is coming through the walls you need to find out why. Look under the floor is the underbuild wet? Leaking pipes flooding underneath?

The extreme solution would be remove the plaster. Put heavy gauge polythene(visqueen) on the walls fix straps to walls. Insulate in between straps and plasterboard. Moisture resistant if you wanted to go the full hog.
There is also insulated plasterboard but its not cheap.

 

[LBoyham]

I think before you do anything you need to be certain what is causing the problem or you will keep throwing money at it.

Sounds like the walls have more that condensation on them if salt is coming through. If it is condensation you need to paint your walls with a barrier paint. Emulsion paints are like putting soil on your walls, add water and guess what happens. A gloss paint (cheap) or egg shell would do it. Crown do bathroom paints for this purpose.

If the damp is coming through the walls you need to find out why. Look under the floor is the underbuild wet? Leaking pipes flooding underneath?

The extreme solution would be remove the plaster. Put heavy gauge polythene(visqueen) on the walls fix straps to walls. Insulate in between straps and plasterboard. Moisture resistant if you wanted to go the full hog.
There is also insulated plasterboard but its not cheap.

Thanks for that information we do have salt coming through and a tide mark now that the tennant has gone we have put the heating on and a humidifer to dry the place out. We have solid floors so its not a leak the place smells of a musty damp smell. There was a leak in the bathroom from the shower. We are having a plasterer out tomorrow one we know and trust so hopefully he will come up with something we have had so many suggestions but no solutions as yet that have worked. Kitchen wall is wet on the inside and plaster is bubbling but there is no ingress of water that we can see. First tennant in the property we had problems, 2nd tennant none and 3rd is the most severe so is it condensation and lifestyle?

 

[Possel]

If you've got mould, then you most probably have a condensation problem due to lack of ventilation as you suspect. You may possibly also have a dampness issue as fmck said, i.e. there's water getting in somewhere and making the condensation problem worse. Check everything - downpipes, gutter, roof slates, internal plumbing, lead flashing, high ground etc and get your neighbours to do the same.

The actual issue could be that most people (including sadly most contractors) do not understand how an old house is meant to work. Being 19th C, it's almost certainly built with lime mortar, not cement, and there is a BIG DIFFERENCE compared to a newer house. With lime the mortar and the walls are meant to breathe, and there were lots of draughts as well, and so normal amounts of moisture evaporated quite easily.

What tends to happen is that over time lots of little changes are done such as plastering or painting with modern materials (which are NOT permeable), repointing with cement (not permeable), fitting uPVC DG (which cuts out all the draughts and so moisture never really gets out) and fitting a chemical DPC (which is at best a waste of money and could actually damage an old house). The result of any/all of these is often increased dampness and then, with good intentions, people come along and try to chase the cause of the dampness and actually make it worse! You have to find out where it's coming from and treat the cause, not the symptom, or else you just push it around.

If you've got any of these things, they are not helping; if any have been done recently, they could be the direct cause of your problem, although it does sound as though certain tenants have been causing it as well. If you can, dry it out and then leave it for a while and see if it comes back, before taking expensive drastic action.

Google for 'Period houses lime mortar' and see what you get. Lime is more specialist than ordinary cement but there are lots of us out here who have knowledge and experience. See my blog at http://houseintheenchantedforest.blogspot.com/ (use the "dampness" filter) for my experience of extensive dampness/water ingress/neglect by previous owner etc.

 

[JohnD]

the most common source of condensation, damp and mould in UK houses is wet washing draped around the home and over radiators.

you say there was also a plumbing leak.

ventilate it OR use dehumidifiers (not both at the same time or the dehumidifiers will be trying to dry the world) and then see what damp patches remain.

The leak may have left floors and walls sodden, they may take a year to dry.

If you have timber floors, verify that all airbricks are clear and not choked with rubble, dirt and cobwebs. If the leak ran through the floor take up some floorboards to let the air flow through. Feel to see if it damp or wet underneath.