Damp proofing

[Irisheyes]

Hi, I had rising damp in my 1903 terraced house. The specialists just finished the wall injection treatment so it’s back to bare bricks. The next step is the plasterer is coming next week to cover it all up again.


thinking about it now, should there be a damp proof plastic membrane fitted between the plasterboard and the brick?

I’m also getting a waterproof membrane painted over the tiles in the dining rm before putting laminate down. I’ve just been researching and I was wondering if I could do this myself? It’s only a layer on paint or is there more to it?

Thanks!

 

[Bingy man]

hi and welcome- are we talking about wet plaster or dry lining . Either way I’ve only ever seen a plastic liner ( vapour barrier) on timber framed houses . Dry lining or wet plaster will not stick to plastic so not much point . In fact I wasn’t sure they still did chemical dpc/ hacking off 1 mtr of plaster etc . As for laminate over tiles you can simply use a damp proof membrane under the laminate. Most of the flooring outlets will sell these and other tho depending on wether you’re laying it on concrete or timber etc . Guess it depends on the cost of this paint. Again I see no reason why you can’t follow the instructions on the tin and diy.. good luck

 

[Irisheyes]

Thank you! The photo shows what my dining area currently looks like! I imagine plasterboard will be fixed to the brick then plastered over, but I was thinking there should be a membrane between the plasterboard and brick… otherwise is it not at risk of moisture?

The tiles oj the floor are the original Victorian tiles on clay. There are sign of moisture on them so I want to make sure there a good layer of waterproofing before I put the underlay and laminate down. I’ve seen t some black paints but if it doesn’t need a specialist to do it, I will have a go myself.

 

[Irisheyes]

 

[Ollie78]

I have been investigating this as we have a similar issue.
From what I gather this should be tanked either with a membrane or a tanking slurry prior to finishing.
Not sure about the floor I have a hung floor which will probably need to come out.
For ours we will be treating it like tanking a basement up to about 1m. We have a high water table.
Our kitchen has an old concrete floor and before we tiled it I painted a 2 pack epoxy down which does seem to have worked. Got it from a tile shop and it was very expensive but you just mix it and paint it on.
However, not sure this will work on your old tiles as there will be movement and then likely cracks will form over time. Maybe a plastic membrane that goes all accross the floor and up the walls would be better ?

Ollie

 

[joncooper27]

Hi you should not Dot and Dab onto the walls as the dabs will suck any of the water and salts out of the walls! What does the company who did the injection recommend are they giving you a warranty?
I am not a great believer in injection systems more on breathability.
You need to be careful with floor somethings are damp, condensation etc.
This website is good reading

https://www.heritage-house.org/damp-and-condensation/managing-damp-in-old-buildings.html

 

[MikeJhn]

Anyone that thinks they have rising damp needs the input of a good surveyor or structural engineer that knows what they are looking at, reasoning, rising damp does not exist the damp is getting into your walls through some other reason, outside ground higher then the inside floor, leaky gutters, leaking bathroom fittings above, a whole industry has built themselves a very good living on this fallacy, please consult a professional.

 

[Adam W.]

It's a bit dry, but worth a watch.

 

[sammy.se]

STOP, in the name of damp.

Is your wall a) and external wall, meaning it's outdoors on the other side; b) a single brick wall, meaning no cavity in the middle of the wall?

If the answer to both of these questions is yes, please please please do not do anything like what you are describing.
I had the same issue. Please search for my thread relating to dining room damp and you will see how it can get solved.

Long story short: The wall must breathe. Therefore - the only plaster to use is lime plaster. The only paint is chalk or lime paint. If you have cement on the outside, you need to hack that off and leave exposed brick or use lime.

There is no other way. Trust me. Check my thread.

BTW, where is your existing slate/bitumen damp proof course - can you see it?

 

[sammy.se]

Anyone that thinks they have rising damp needs the input of a good surveyor or structural engineer that knows what they are looking at, reasoning, rising damp does not exist the damp is getting into your walls through some other reason, outside ground higher then the inside floor, leaky gutters, leaking bathroom fittings above, a whole industry has built themselves a very good living on this fallacy, please consult a professional.

Very very true.

Check these: Any gutter leaks, downpipe leaks, pooling water not going into drains. Even a tiny drip will accumulate over time, get absorbed into your walls and find no way to escape if there is cement, or gypsum plaster, or modern paint on the walls. Check the Damp Proof Course (DPC), likely to be slate in your house, but could be bitumen. There should be nothing 'bridging' your DPC, meaning, it should be visible, and no render or floor (inside) should be covering it.

 

[sammy.se]

https://www.ukworkshop.co.uk/threads/damp-in-victorian-house-dining-room.116193/

 

[Fitzroy]

Rising damp does exist, you can place a brick in a water and demonstrate capillary action resulting in water above the level in the bowl. Houses were built with damp proofing courses in their brick work as protection. Does this mechanism result in the issues that people see as damp in their property, based on the research that I have done not in the vast majority of cases.

Damp is a complex situation and water can track from the point of entry to another totally different location, meaning that the fix is not always an obvious one. Additionally once the building structure is wet it can take a long time to dry out, months and into years, so it can feel that an intervention has not been successful.

My brother was caught out by the damp proof industry last year and I just wish I'd known earlier so that I could try and steer his path.

 

[Adam W.]

@Fitzroy Did you watch that video that I posted, I'd be interested in hearing your thoughts on it.

 

[Stuart Moffat]

The front half of my house was built about 1890 and was plastered straight onto a 9” wall with various repairs before I moved in had been done with inappropriate materials. About 8 months ago I had damp problems in 2 rooms, and bit the bullet. I took all the plaster off back to the brick. Put lathes onto the wall and made sure there was ventilation in the 25mm gap that created through to the loft. I got a plasterer to fix 25mm insulation over the boards (and tape over any gaps, and dry lining fixed over that (you can buy insulated plasterboard to achieve the same thing). The result is that what we’re cold damp walls are now warm and dry. Only needed on the external walls.
No chemicals needed, just lime mortar pointing maintenance.
Stuart

 

[Fitzroy]

@Fitzroy Did you watch that video that I posted, I'd be interested in hearing your thoughts on it.

I am completely aligned with the video. When I was selling a property in London I had a surveyor stick his conductance moisture meter in my wall, declare rising damp, and that I needed the whole thing damp proofing. That’s what started my research. I came to the conclusion my issue was a leaking toilet overflow, and blocked up air bricks. Fixed them both and the wall damp patch disappeared over the next 4 months.

However evangelism exists at both ends of the damp spectrum, and I think it damaging to the fair debate of a subject to denounce something outright that can be shown to exist in a theoretical setting. At the start of the video both gents admit that water can rise in a brick, or certain types or brick, due to capillary action.

Fitz.

 

[gregmcateer]

.... At the start of the video both gents admit that water can rise in a brick, or certain types or brick, due to capillary action.

Fitz.

Thanks all of you gents for sharing your knowledge and experiences.

Is the capillary action the reason for a DPC? Otherwise, I'm not sure why we would need one

Thanks in advance

Greg

 

[Adam W.]

Thanks all of you gents for sharing your knowledge and experiences.

Is the capillary action the reason for a DPC? Otherwise, I'm not sure why we would need one

Thanks in advance

Greg

Based on the information in that video, you could argue that it isn't necessary, although you won't get your work passed by Building Control if you didn't have one.

There you go, completely ambiguous and open for debate, like most things in life.

 

[gregmcateer]

I've just watched the video - as said, very dry, (excuse the pun), but v interesting

 

[MikeJhn]

here you go, completely ambiguous and open for debate, like most things in life.

I don't think it is ambiguous or open for debate, "Rising Damp" as the lay person understands that term does no exist, capillary action will allow damp to rise up into a brick or wall structure, but not to the extent of more than one brick, the mortar joint will prevent that.

One interesting case I had of investigating "Rising Damp" was down to the splashing of a puddle in the road outside the house when vehicles passed, the so called "Rising Damp" was due to a blocked surface water drain, this was missed by all the so called high street "experts".

 

[woodieallen]

I was recommended this guide.

https://www.watco.co.uk/help-advice...ok#ebook-guide-to-waterproofing-damp-proofing