Damp

[M S E Refugee]

After being quoted astronomical prices to stop damp in my House I now wondering if I should get rid of the damp dot and dab gypsum plasterboard downstairs and just re-point the rubble walls with lime mortar and just lime-wash the walls instead of lime plastering them.

This is a job me and the missus could do for very little cost.

We have done this with one of the walls in our bedroom without lime-washing it and so far no issues.

[Long time lurking]

3 minutes ago, M S E Refugee said:

Yes I think you are right in your assessment as the plaster board dries out if we get a few dry days.

It`s well worth looking on youtbe for Lime pointing 

it`s also worth looking for damp from thermal bridging you will be able to come to your own conclusion then 

With thermal bridging damp  the water is almost always from within the house 

[Caravan Monster]

Is construction a mass wall ie 3' + thick stone facing and rubble fill and are there concrete floors?

[Caravan Monster]

1 hour ago, M S E Refugee said:

The soil level at the back of the house is slightly higher but we have no damp issues at the back of the house.

I will just probably remove the plasterboard that is damp and either re-point the stonework and lime-wash it or get someone to re-plaster with Lime,the first option would be far cheaper and I think it should work as it will make the wall more breathable.

That's probably the best route, taking up concrete floors and replacing them is a big undertaking. Don't be afraid to give lime plastering a go, it's much easier than gypsum because it's so slow to go off, give the bare walls plenty of water before you start, get it about right and trowel it smooth as it starts to harden. Mass walls are amazingly resilient and effective. In my area, they quite often packed the centre of the wall with chopped straw instead of the more conventional stones and mortar which you would think would be a recipe for disaster but I have seen several which are fine at 300+ years old.

[Harley]

Dot and dab on solid walls not good.  Board out with s 50mm ventilated air gap or lime plaster, hemp mix being my favourite.  Limewash also OK, cheap and in many colours.  Lime is naturally anti-fungal as well as breathable.  But hemp mix not good if you may want to board out later as it is organic.  Building regs may apply if over a certain area for some options.

PS;  Trying to decide right now between a boarded insulated or natural lime plaster solution for a small area.  Probably go for plaster.  Insulating a small area when massive window reveals, etc are exposed is pointless.

[M S E Refugee]

This is the type of look I would get if I take off the plasterboard and limewash the walls.

[Long time lurking]

10 hours ago, M S E Refugee said:

There are large damp patches that seem to be emanating from the dot and dab plasterboard.

Also the front and the gable end of the house has been cement rendered and this is where I have the damp internally.

The house is nearly 200 years old and I live on the English side of the Solway Firth.

Are they west south/west facing ?

If its just where the dot and dab plaster board is, my guess is its just condensation cause by thermal bridging

Somewhere around the middle of the patch you might find a solid sounding part if you tap it  that is where the "dab" is which is the thermal bridge  from a cold stone wall to a warm plaster board 

[Caravan Monster]

9 hours ago, M S E Refugee said:

The walls are probably 3 foot thick constructed from sandstone,brick and cobbles, the previous owner has put in concrete floors.

Pavement or soil stacked up above floor level outside as well? The concrete floors are the primary cause of the moisture because it would have previously escaped into the atmosphere through the flooring, between the joints of the flagstones or straight through the rammed earth or whatever was there. There is no damp course (or much foundation) in that type of wall so moisture does travel up it, and all the moisture under the house footprint goes up the wall once the floor is covered in dpc sheet covered by concrete. Plasterboard is the worst because you get that weird smell of wet stone trapped by it.

Old houses worked by plenty of air circulation and more heating, in contrast to post war and particularly more recent, which is more trying to make the house very draught proof. Old and new methods and materials can overlap to a degree, but it takes a bit of experience to get good results. Don't believe too much of what is on the web about old buildings because most of it is produced by people selling particular products or services and a lot of self proclaimed experts don't have much experience and often quite wild imaginations.

[spunko]

You can get a lime-type finish using Limewash as well. The paints are naturally quite expensive, although I'm not too sure why some say they need to be applied by a professional - presumably because theyre slightly caustic?

[Andersen]

Another forum that has a load of good advice https://www.periodproperty.co.uk/forum/viewforum.php?f=1&sid=268acf23d8b5edf7abb0f9b007af508e

I was in an old farmhouse recently where they have removed the old plaster from several walls and repointed using lime plaster ( with a very pale green tint ) to make "feature" walls. They look very smart and up-market. Maybe an option for you?

[spunko]

Need a bit more information.

Where abouts in the UK are you roughly?

How old is the house, what are the walls (external) made of, and what type of damp is it?

Wet rot, Dry rot, condensation, rising damp etc.

[M S E Refugee]

2 hours ago, Caravan Monster said:

Is construction a mass wall ie 3' + thick stone facing and rubble fill and are there concrete floors?

The walls are probably 3 foot thick constructed from sandstone,brick and cobbles, the previous owner has put in concrete floors.

[M S E Refugee]

24 minutes ago, spunko said:

Need a bit more information.

Where abouts in the UK are you roughly?

How old is the house, what are the walls (external) made of, and what type of damp is it?

Wet rot, Dry rot, condensation, rising damp etc.

There are large damp patches that seem to be emanating from the dot and dab plasterboard.

Also the front and the gable end of the house has been cement rendered and this is where I have the damp internally.

The house is nearly 200 years old and I live on the English side of the Solway Firth.

[One percent]

There was a thread very similar to this a while back. Don’t know if it ever got resoled but it might be helpful. Someone else might be able to find it for you 

[spunko]

37 minutes ago, M S E Refugee said:

There are large damp patches that seem to be emanating from the dot and dab plasterboard.

Also the front and the gable end of the house has been cement rendered and this is where I have the damp internally.

The house is nearly 200 years old and I live on the English side of the Solway Firth.

Ah, bit far away from me, not really sure on the local vernacular. If that was down here where we have fairly hot, dry summers and not much rainfall in winter I'd say yes, rake out all the pointing and take off the render and do it in lime mix.

[Van Lady]

I think this is a great site with lots of great info about old houses and the correct way to deal with damp, materials to use etc.

https://www.heritage-house.org/

[M S E Refugee]

1 hour ago, Caravan Monster said:

Pavement or soil stacked up above floor level outside as well? The concrete floors are the primary cause of the moisture because it would have previously escaped into the atmosphere through the flooring, between the joints of the flagstones or straight through the rammed earth or whatever was there. There is no damp course (or much foundation) in that type of wall so moisture does travel up it, and all the moisture under the house footprint goes up the wall once the floor is covered in dpc sheet covered by concrete. Plasterboard is the worst because you get that weird smell of wet stone trapped by it.

Old houses worked by plenty of air circulation and more heating, in contrast to post war and particularly more recent, which is more trying to make the house very draught proof. Old and new methods and materials can overlap to a degree, but it takes a bit of experience to get good results. Don't believe too much of what is on the web about old buildings because most of it is produced by people selling particular products or services and a lot of self proclaimed experts don't have much experience and often quite wild imaginations.

The soil level at the back of the house is slightly higher but we have no damp issues at the back of the house.

I will just probably remove the plasterboard that is damp and either re-point the stonework and lime-wash it or get someone to re-plaster with Lime,the first option would be far cheaper and I think it should work as it will make the wall more breathable.

[M S E Refugee]

10 minutes ago, spunko said:

Ah, bit far away from me, not really sure on the local vernacular. If that was down here where we have fairly hot, dry summers and not much rainfall in winter I'd say yes, rake out all the pointing and take off the render and do it in lime mix.

We get lots of rain here all year round,most of the house seems to be okay despite being partially entombed in cement.

We have found a contractor that specialises in Lime work but the weather has been terrible and they are in high demand as very few builders do this kind of work.

There must be a huge market to restore old houses using traditional methods after years of vandalism by modern builders and damp-proofers using cement.

[spunko]

16 minutes ago, M S E Refugee said:

We get lots of rain here all year round,most of the house seems to be okay despite being partially entombed in cement.

We have found a contractor that specialises in Lime work but the weather has been terrible and they are in high demand as very few builders do this kind of work.

There must be a huge market to restore old houses using traditional methods after years of vandalism by modern builders and damp-proofers using cement.

 I haven't found many people round here who seem to know what they're talking about... Occasionally you find an "expert" but then you scratch the surface and they're full of shite...

BTW, lime mortar (if thats what you mean) shouldn't be used if there is a risk of frost in the next 2 weeks.

https://cornishlime.co.uk/news/tips-winter-work/

 

[M S E Refugee]

1 hour ago, Long time lurking said:

Are they west south/west facing ?

If its just where the dot and dab plaster board is, my guess is its just condensation cause by thermal bridging

Somewhere around the middle of the patch you might find a solid sounding part if you tap it  that is where the "dab" is which is the thermal bridge  from a cold stone wall to a warm plaster board 

The front of the house is south facing and the gable faces west.

[Long time lurking]

1 minute ago, M S E Refugee said:

The front of the house is south facing and the gable faces west.

Well that`s into the weather if its just patches in random places i would think it`s condensation causing it through thermal bridging especially so if the problem is less of a problem in the warmer whether 

If its starting at a particular point /height and traveling down i would be looking at the render / pointing on the outside in the area of the highest point of damp  on the inside 

There`s loads on youtube on lime pointing 

[M S E Refugee]

1 minute ago, Long time lurking said:

Well that`s into the weather if its just patches in random places i would think it`s condensation causing it through thermal bridging especially so if the problem is less of a problem in the warmer whether 

If its starting at a particular point /height and traveling down i would be looking at the render / pointing on the outside in the area of the highest point of damp  on the inside 

There`s loads on youtube on lime pointing 

Yes I think you are right in your assessment as the plaster board dries out if we get a few dry days.