Damp Bedroom - Need Quick Fix!

[JohnB]

I've got damp in a ground floor bedroom that I need to decorate and get a lodger in ASAP. I've read through the damp topic, and think I've picked out all the relevant stuff. In the long term I'd aim to do the job properly, but for now I need to make it habitable as quickly and cheaply as possible. Here's the details, and pics:

Ground floor bedroom 15ft x 9ft. Years ago it had a storage heater, but it currently has no heating.

3 walls 2ft thick stone with earth mortar
- 1 x external with large uPVC double glazed window fitted about 3 years ago, facing ENE
- 1 x former external, but has had kitchen extension on other side since late 1960s
- 1 x party wall with what was originally a separate house. Other side of wall gypsum plastered in last 7 years, no heating, and until some weeks ago there was no external door. This room is showing signs of damp, and where I've removed loose plaster on external wall was very wet
1 wall internal, solid, single skin. On other side is sitting room that doesn't have very good heating, with almost no sign of damp.

The walls seem to have been levelled with cement with a thin gypsum plaster skim, probably in the late 1960s. There is a coat of old paint on the plaster, covered with a more recent coat of trade emulsion (I've got the rest of the tin the previous owner said he used).

Concrete floor with laminate flooring. Under about half an inch of concrete is a very thin transparent plastic sheet. Skirtings have not been fixed to wall so have been removed. The laminated floor is laid on expanded polystyrene underlay, and appears to be dry.

Outside there is a concrete path almost exactly at internal floor level, and touching the base of the wall.

Outside wall is cement rendered and pebbledashed. There are some cracks. There is guttering, and I don't think it leaks. No drains, and downpipes deposit water at the base of the wall. Nearest one is about 15ft away on end wall.

Signs of damp mainly on outside wall and on adjoining walls (party wall and internal wall) for a short distance. Black mould and salts on surface. Party wall is the worst bit.

Had a dehumidifier with humidistat running for several weeks in it's Auto mode. It's extracted a lot of water, and the room definitely has less of a musty mouldy smell.

I've removed some patches of paint where it's lifted, as shown in the photos.

View attachment 2
View attachment 1


Any suggestions about what I should do?

 

[JohnB]

This is where I scraped off the paint where it has lifted, and got right back to the cement

 

[OddJob]

To use a phrase a retired mechanic friend used to use when people did horrible things to perfectly good cars,
"Hmm...dunno,but it sounds expensive".

 

[Pford75]

John - Couple of thoughts...

1. Speed and removing damp are not happy bedfellows...some things just take time to dry out properly

2. That said, our own experience with lodgers/tenants is that their usage of the room can often be a key factor in damp. For example, tenants may resort to drying washing in their room on radiators if they don't have access to other drying facilities. Similarly, we had a tenant who simply did not open windows and spent a large proportion of time in one room (since the bedroom may double as living accomodation/dining room etc.).

With the best will in the world, some properties (when used in this way) will always have a problem with damp. You need to enlist lodgers in helping to increase ventilation or the problem will recur

 

[Flyfisher]

I agree with the previous post and would also add that things could quickly get complicated if an uncooperative lodger/tenant in a damp property called in the environmental health people or stopped paying rent until you made the accomodation 'fit for habitation'.

 

[JohnB]

I think the room has dried out pretty well. I haven't got a very good sense of smell, but the smell of damp appears to have gone. I think what I can smell now is because the previous owners smoked. I slept in the room last night, and it seemed ok. I really need to get the room fit for use through the summer. I'll have to do something about heating in time for winter, and start on the big jobs, like removing the path and render, but can't do that yet. By that time I should have other rooms available, so the tenant could move into one of them while I do a more permanent job.

I was really thinking of finding the best way to prepare and decorate the room at this stage. The lodger will have to be educated in the proper way to use the room!

 

[robgil]

ive heard of damp being caused by many things , but lodgers? eliminate the damp before you rent the property.having to sort a damp issue will only antagonise a paying tennant , this could cause all kinds of problems , reduced rent etc etc.
you need to eliminate the cause of damp, not the effects.

 

[essexbearhunter]

Depending on how it would work with the rest of the room, you could remove all plaster from the lower section of the wall (to dado rail height). This would allow damp area at the base of the wall to breathe better. Then, with tanalised horizontal mounting battens (to raise it off the face of the wall and give room for air circulation) matchboard the stripped lower section of the wall to dado rail height, making sure that there are ventilation holes or grills (perhaps even a section of radiator grill) in the fascia.

This would help break the moisture path up the plaster, ensure that ventilation was was maintained over the worst section of the wall and replace obviously damaged plaster with a more appealing freshly-painted wood finish in the short term.

Whether this is what you would term a "Quick Fix" is down to you, but (apart from the annoyance of dust generated by the removal of plaster) it is is fairly simple and about the bare minimum that you could get away with.

 

[Penners]

Speed and removing damp are not happy bedfellows...some things just take time to dry out properly

I wholeheartedly agree. And this poor wall has been just about as mistreated as it could possibly be (by previous owners).

Whatever solution you adopt, you need to get the cement and gypsum off the wall and give it a good long time to dry out. The impending summer should be good for this (note that I said should! :wink:. This not an official forecast!).

But if you absolutely have to do something quickly to make the room habitable, then I reckon essexbearhunter's solution is your best bet. Do take heed of his comments about copious ventilation.

 

[chuckey]

Bottom corners of outside walls are the coldest part of any room and are prone to condensation and mould growth ( black spots in first picture). Gypsum plaster are like sponges they will soak up excess water and take time to dry out. If subject to excessive moisture over a long time they will turn to pulp. Ideally rooms should be kept at a minimum of 12 deg C to minimise condensation, yeh, I know, I don't either. What to do?, allow the wall one week for every 1" thickness for it to dry out and then review the situation.
Frank

 

[JohnB]

Thanks. I think the wood panelling option is the best one. It doesn't need to be done to the whole room, just part of one end, so might make a nice break between the sleeping end and the sitting end. I need the income from lodgers, so don't have the luxury of doing all the right things to the room, and waiting for it to dry out. That can be done later.

 

[Penners]

Just make sure you take off the cement and gypsum behind the panelling, and leave a ventilated air-gap. Otherwise you risk worsening the problem by boxing it in.

 

[JohnB]

Just make sure you take off the cement and gypsum behind the panelling, and leave a ventilated air-gap. Otherwise you risk worsening the problem by boxing it in.

I will. I want to see what the stone is like. I was thinking of using vertical timbers, leaving a gap at the bottom of the boarding, and a gap at the top, with a capping strip/small shelf above. I'd make the panelling removable. Would half inch gaps be enough?

 

[essexbearhunter]

using vertical timbers, leaving a gap at the bottom of the boarding, and a gap at the top, with a capping strip/small shelf above. I'd make the panelling removable. Would half inch gaps be enough?

This should give good air movement. It would be useful if the distance between the bare wall and the inner face of the panelling is not less than 1inch, to increase the body of air soaking up the moisture and promote movement. This also has the benefit of giving a more usable depth of shelf

 

[JohnB]

This should give good air movement. It would be useful if the distance between the bare wall and the inner face of the panelling is not less than 1inch, to increase the body of air soaking up the moisture and promote movement. This also has the benefit of giving a more usable depth of shelf

To make the panel removable, I thought 1" battens fixed to the wall, then another 1" on the back of the panels to hold them together, so I get a 2" gap. I could then reuse the panelling when I do a proper job, if I need to.

 

[Penners]

That sounds like a good plan. To improve the general wafting about of air (I'm not getting too technical for you, am I? :wink: ) between the wall and the panelling, it might be an idea to have the wall-mounted battens as several short strips, with gaps between them, rather than continuous. This would avoid the creation of lots of individual pockets of air.

Make sure you use treated timber for the wall-mounted battens, and it might be a good insurance policy to place a layer of plastic film slightly wider than the batten between each wall-mounted batten and its corresponding panel-mounted batten. This would greatly reduce the amount of moisture transmitted between the two.

I hope this explanation makes sense. If it doesn't I'll attempt a sketch.

 

[JohnB]

I don't even need battens, just some small blocks, allowing unrestricted airflow. Then I could put the plastic on the wall so I don't need treated timber. The contact area would be so small I wouldn't have thought it would cause a problem.

 

[Penners]

I agree.

 

[JohnB]

Whoever did this must have shares in a cement producer :evil:. There's almost 2" of it.

View attachment 1
The top layer will come off in big chunks, but the bottom layer needs care, as it's harder than the stone. There is some obvious dampness in the mortar, but the stone appears to be dry. There is some lime pointing left on the earth mortar, but no sign of lime plaster that I assume it would have had.

As the cement is so thick, is there any connection between the damp in the room, and the stone wall not being able to breath?

 

[Schoolmarm]

If the wall is bone dry underneath it could well be condensation alone.