1860s stone house Reno

[brianos]

oh, I forgot to mention.. the owner before the previous owner had one of these fitted. it still appears to be switched on. well, I press the button and the light comes on. I've read up on these electro osmotic things. They sounded like 'emperors new clothes' type kit from the mid 70's. Perhaps a little like this membrane stuff possibly?

 

[aockenden]

@aokenden --- yeah, I'm not getting initial positive vibes from your initial response ;o) the exact text from this specialist firm is below...


"VERTICAL WATERPROOF MEMBRANE
In certain circumstances it will be necessary to damp proof the walls against lateral penetration of dampness i.e. from high ground or floor levels and from the ground surrounding basements.
Where this is applicable our Tanking process will be carried out using an impervious vertical membrane which will be incorporated into the plastering and applied to the heights specified.
Solid Floors. Damp or damaged floors should be replaced in concrete incorporating a suitable liquid damp-proof membrane to be flushed up the wall to the damp course level.
Dry Lining. Where preferred, as an alternative to wall plaster or where additional insulation is required, dry wall linings may be used. Foil backed plasterboard should be fixed on pre-treated timber battens at approximately 400mm centres. Greater insulation values will be obtained if 25mm or 50mm fibreglass insulation is inserted beneath the plasterboard. The battens and plasterboard must be terminated approximately 25mm and 50mm above the floor. The gap thus formed may be covered using pre-treated timber skirtings.
Condensation. Adequate heating and ventilation must be maintained in order to avoid damage to internal decorations caused by condensation.
Decoration. The use of Non Vinyl emulsion is recommended on all walls treated.
DO NOT USE VINYL EMULSION OR WALLPAPER for a period of six months.
All rainwater goods and plumbing should be maintained in good order."

Yeah that's all just the typical bodge-it builder "damp proofing" junk that has damaged countless old buildings. It's sad that this is what is coming out of a "well respected preservation company". It all sounds like a great way to end up with sopping-wet walls and a nice case of asthma.

 

[aockenden]

oh, I forgot to mention.. the owner before the previous owner had one of these fitted. it still appears to be switched on. well, I press the button and the light comes on. I've read up on these electro osmotic things. They sounded like 'emperors new clothes' type kit from the mid 70's. Perhaps a little like this membrane stuff possibly?

View attachment 13114

 

[stuart45]

So this "vertical membrane" = some kind of cementitious tanking slurry or blackjack bitumen paint layer that they want to slather onto the inside of your walls before replastering?

There's a few different methods, although this one could be something like a Visqueen self adhesive membrane that comes in 20x1M rolls, or some that need fixing to the wall. They normally dot and dab plasterboard on top.

 

[a twig]

oh, I forgot to mention.. the owner before the previous owner had one of these fitted. it still appears to be switched on. well, I press the button and the light comes on. I've read up on these electro osmotic things. They sounded like 'emperors new clothes' type kit from the mid 70's. Perhaps a little like this membrane stuff possibly?

View attachment 13114

I’ve always wondered if you opened one of those up you’d just find wiring connecting the light to the button and nothing else

 

[brianos]

Yeah that's all just the typical bodge-it builder "damp proofing" junk that has damaged countless old buildings. It's sad that this is what is coming out of a "well respected preservation company". It all sounds like a great way to end up with sopping-wet walls and a nice case of asthma.

Can you help me understand why its a bad idea and what are the alternative directions I might take? and, is the DPC also a bad idea or is it just the membrane thats a really bad idea?

 

[aockenden]

Can you help me understand why its a bad idea and what are the alternative directions I might take? and, is the DPC also a bad idea or is it just the membrane thats a really bad idea?

I'm really sorry, my energy to devote to explaining these things for folks is waning. Please look deeply into the topics of breathability (aka vapour permeability), moisture-wicking (aka capillarity), relative humidity, dew-point, condensation, mold etc. in relation to old solid, cold-walled buildings. I recommend taking no major action on your house until you have a deep understanding of these topics. Checkout the book "Clay & Lime Renders, Plasters & Paints". I recommend reading that book cover-to-cover, even if you aren't going to be doing the work on your house yourself.

 

[a twig]

This forum has over 15 years of similar questions being asked, a quick search for “injected doc” would be a useful provider of primers as it would bring up a lot of helpful threads. There are also other useful ones like this one:

I’ve just bought an old house and it’s damp, help!

So, many people have suggested over the years this should just be called the “old damp house forum” So I thought I should start a basic guide to tackling damp in a period property that hopefully the learned members of this parish can add to, and we can then point others to in the future...

www.periodproperty.co.uk

 

[brianos]

I'm really sorry, my energy to devote to explaining these things for folks is waning. Please look deeply into the topics of breathability (aka vapour permeability), moisture-wicking (aka capillarity), relative humidity, dew-point, condensation, mold etc. in relation to old solid, cold-walled buildings. I recommend taking no major action on your house until you have a deep understanding of these topics. Checkout the book "Clay & Lime Renders, Plasters & Paints". I recommend reading that book cover-to-cover, even if you aren't going to be doing the work on your house yourself.

I totally get it. I will read the doc that 'a twig' posted. I did read the website from Heritige House on topic -> https://www.heritage-house.org/damp-and-condensation/managing-damp-in-old-buildings.html which explained the criticality of breathability and his fundamental challenges to the concept of rising damp. I totally appreciate you guys are battle fatigued on the topic in the forum. When I originally posted, I had read some posts from the chap behind heritige house website but it sounded a bit 'conspiracy theory', especially when contrasted with an entire damp proofing industry and almost all the professional surveyors I had spoken to telling me that DPC and membrane is a no-brainer on an old property.. which is why I posted to get another view and some validation on what the chap at Heritige was saying. your time is appreciated and it makes an important difference to peoples lives.

The remaining question I have relates to the fact that my 1700s cottage is completely covered in a render externally and painted (I'm guessing neither will have been breathable materials). So, where does that leave me in terms of the overall breathing strategy for the building? I assume the answer is that, having the internal walls being able to breathe is (even more) critical given its the only route for any moisture to escape via. And... that condensation will almost certainly be sitting inside the render on the external walls. Which begs the question - should I spend money on chipping all that render off?! I'm a 1's and 0's computer guy and cant nail up a shelf. The wife bought this place so having to learn. It is interesting stuff though. but.. hard when the majority of the grown ups keep telling me to do a DPC and membrane! Also, she has set her heart on DPC and Membrane as the nirvana of warmth and dryness. Marital guidance also welcomed.

 

[aockenden]

I totally get it. I will read the doc that 'a twig' posted. I did read the website from Heritige House on topic -> https://www.heritage-house.org/damp-and-condensation/managing-damp-in-old-buildings.html which explained the criticality of breathability and his fundamental challenges to the concept of rising damp. I totally appreciate you guys are battle fatigued on the topic in the forum. When I originally posted, I had read some posts from the chap behind heritige house website but it sounded a bit 'conspiracy theory', especially when contrasted with an entire damp proofing industry and almost all the professional surveyors I had spoken to telling me that DPC and membrane is a no-brainer on an old property.. which is why I posted to get another view and some validation on what the chap at Heritige was saying. your time is appreciated and it makes an important difference to peoples lives.

The remaining question I have relates to the fact that my 1700s cottage is completely covered in a render externally and painted (I'm guessing neither will have been breathable materials). So, where does that leave me in terms of the overall breathing strategy for the building? I assume the answer is that, having the internal walls being able to breathe is (even more) critical given its the only route for any moisture to escape via. And... that condensation will almost certainly be sitting inside the render on the external walls. Which begs the question - should I spend money on chipping all that render off?! I'm a 1's and 0's computer guy and cant nail up a shelf. The wife bought this place so having to learn. It is interesting stuff though. but.. hard when the majority of the grown ups keep telling me to do a DPC and membrane! Also, she has set her heart on DPC and Membrane as the nirvana of warmth and dryness. Marital guidance also welcomed.

Dude, your talking to a lead data and infrastructure Azure cloud engineer, but I also do a lot of this renovation / restoration stuff myself. I hacked every ounce of cement render off our stone cottage's exterior walls myself with a hammer and a chisel (including up on a rented scaffold tower) in preparation for sand-blasting and lime repointing, among a whole host of other projects on the house. So I would encourage you not to pigeon-hole yourself! For me the renovation / restoration work has become much more interesting than writing my 10 millionth Python ETL.

As for your external render questions, the first step is to confirm the materials used. Pics would help as certain styles are very easily identifiable as cement, but the best way is to actually chip off a small piece in some inconspicuous area and look at the colour and the hardness. Dull grey and very hard / brittle almost always indicates a cementitious render. And any heavy peeling / flaking of paint is usually a good indicator that the paint is non-breathable. But generally speaking you're right to be suspicious that it's been done with improper materials, as the VAST majority of old houses that have been rendered / painted you'll find in 2024 have been done with cement and plastic masonry paint.

 

[malcolm]

The basics are really easy and from there you can check any advice.

A wall gets wet when more water gets in than can get out. Water is always going to get in - it seeps up from the ground into the walls and also gets in by rainfall and condensation.

So it's important to make sure water can get out. A breathable exterior is the biggest drier for the wall. Should that not be breathable then you really want the interior to be breathable.

That means no cement
, gypsum plaster or any modern plastic or emulsion paint.

A DPC can be useful on a floor but rarely on a wall.

I'm good at turning computers off and then back on again.

 

[brianos]

Dude, your talking to a lead data and infrastructure Azure cloud engineer, but I also do a lot of this renovation / restoration stuff myself. I hacked every ounce of cement render off our stone cottage's exterior walls myself with a hammer and a chisel (including up on a rented scaffold tower) in preparation for sand-blasting and lime repointing, among a whole host of other projects on the house. So I would encourage you not to pigeon-hole yourself! For me the renovation / restoration work has become much more interesting than writing my 10 millionth Python ETL.

As for your external render questions, the first step is to confirm the materials used. Pics would help as certain styles are very easily identifiable as cement, but the best way is to actually chip off a small piece in some inconspicuous area and look at the colour and the hardness. Dull grey and very hard / brittle almost always indicates a cementitious render. And any heavy peeling / flaking of paint is usually a good indicator that the paint is non-breathable. But generally speaking you're right to be suspicious that it's been done with improper materials, as the VAST majority of old houses that have been rendered / painted you'll find in 2024 have been done with cement and plastic masonry paint.

 

[brianos]

@aockenden Information copied sir. I'm pressed with the dedication of hacking your place back to original stone. Thats dedication for sure! I'll take a look at the render and report back. The pain hasn't peeled anywhere at all. If it were pervious paint ontop of impervious render, I don't suppose that really means anything right. The wall is in the same condition.

If we end up living with an impervious render - from a maintenance point of view, should we continue to maintain it as impervious. i.e. any hairline cracks filled with impervious rather than pervious render?

I might even be getting my hands dirty this weekend and taking a bookshelf down. Wish me luck.

Cheers!

 

[jamest]

Living with impervious render is a problem because it will inevitably crack a bit and let water into the wall. Try as you might to seal up all cracks, you'll miss some and water can get in through the tiniest of gaps, even those invisible to the naked eye (so you'll need to use impermeable paints and re-apply every year or two). Over time the wall will inevitably get a bit damp within the impervious coatings, if it isn't already. A damp wall is a very good conductor of heat, much better than a dry wall, so you'll end up with much colder walls (though it might take a while to have a significant effect depending on the rigor of your maintenance schedule). You'll then have higher heating bills and potentially condensation problems on the inside. Ultimately, you have a decision to make: do I stick with the impervious coatings and have higher heating bills (though maybe not much higher, hard to know), the risk of interior condensation problems and a tedious on-going maintenance job? or do I strip the walls and apply breathable coatings?

 

[brianos]

Here's a couple of pics. Assuming the pics are presented to you in the same order I see them.. the first is a view of the back of a lamp I broke off the render. The 2nd is a pic of the old wall peeping out from the render. (Render is around 1 inch thick) and the last was of the paint. The paint pic does look a teeny weeny bit flakey

 

[aockenden]

Here's a couple of pics. Assuming the pics are presented to you in the same order I see them.. the first is a view of the back of a lamp I broke off the render. The 2nd is a pic of the old wall peeping out from the render. (Render is around 1 inch thick) and the last was of the paint. The paint pic does look a teeny weeny bit flakey

View attachment 13130

View attachment 13131

View attachment 13132

Looks like cement at first glance. How hard is it? If you hit it with a hammer does it crack and shatter or does it more crumble? Can you crumble it with a light tap of a small hammer?

 

[brianos]

Looks like cement at first glance. How hard is it? If you hit it with a hammer does it crack and shatter or does it more crumble? Can you crumble it with a light tap of a small hammer?

Negative. Its pretty tough. Some more pics of where render ends and remainder if wall is exposed original stone and mortar

 

[aockenden]

Yeah that super iron grey topmost layer is very likely cement and that’s not surprising at all. Very typical in 2024.

 

[brianos]

Yeah that super iron grey topmost layer is very likely cement and that’s not surprising at all. Very typical in 2024.

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