Limecrete or Concrete Floor Slab?

I share my thoughts about the floor slab of our house conversion.
Tip jar: bmc.link/homeprojecv
Chapters:
00:00 - Intro
00:24 - Explanation of Work
02:14 - The Argument goes...
03:00 - The Issue with Our Floor
04:57 - Is a Limecrete Floor worth it?
05:50 - PPE
06:50 - Advice
10:00 - Shifting My Mindset
14:50 - The Point of This Video
Music:
Jeff Kaale - Candlelit
Moire - Forest in Hand

[@wakeyjamie]

I was in a similar position to you, we live in a damp house in North Wales. I was told by numerous lime experts that NHL5 used in limecrete floors sets harder than concrete. So in the end we used a 'hybrid' floor system. We used Geocell foamed glass as the dampproof membrane, and then a normal concrete screed. So far, all good.

[@DavvidBee]

just out of curiosity, what thickness of the foamed glass you made? and have you used any other damp-protection or left small empty space between wall and concrete floor to let the vapour escape under the floor to the room?

[@stihl3826]

Foam glass is the insulation. The membrane is the geotextile underneath.

[@stevejohnstonbaugh9171]

As I told you looong ago, the American Institute of Architects licensing exam has only one correct answer to the question; " How do you solve a water/moisture problem?" The only correct answer is "Pipe it away". You have followed that advice and the barn floor soil is now dusty! You are correct. Limecrete is a not a panacea - but it is a politically and sociologically loaded gun.

[@Harryset1]

A while ago we had to deal with a similar situation: - here is we what did - i drilled a lot of holes into the original concrete slab - so no structural damage done - then we did put a "ton" of leftover "leca" aka "Blähton" aka "expanded clay products" - leftovers from a failed hydroponics greenhouse on top of the slab - then a membrane. To build the new floor we used reclaimed 10x12cm beams - old and well stained - in a square grid - sort of ;) -- felt strips on the beams - so no squeaky noises -- the floor itself: reclaimed beautiful hardwood "Groove and joint boards" almost 35mm thick. to make and build a connection to the walls we used rubber strips cut out an old conveyor belt. We had to be very careful with the cutting on the table saw- because of the thin metal mesh inside the belt. The grooves and joints we did seal with a permanently elastic adhesive (glue). Then we worked it over with the infamous Parquet sander ----- (one of my fav jobs) -- after that - we used a lacquer-finish product to seal and paint it. Final Result: A beautiful blond floor -- without moisture or other problems -- the air does circulate well - we heat well - and "stoßlüften" aka all windows open for 5 mins often during a day is highly recommended. Thats it -- and all the best to you and your loved ones. Greets - H.

[@cmicarsdenmark200]

Renovated our damp boulder house, living in a valley, close to a creek and have high ground water. 20cm gravel, with a drainpipe under around the outer walls, going through 1 place to a well outside. 10cm flamingo insolating the edge against the walls, a sheet of plastic over the sand, then 30cm flamingo insolation, rebar, floor heating and then concrete. When building new walls, i laid something we call "murpap" is kind of like a thick plastic on the flamingo edge, glueing it down. Then rockwool insolation over the murpap and flamingo edge. As the new inner wall, I used Ytong (aerated concrete) because it can breath. Never had a better inner clima in the house before, as we have now.

[@fitzspj]

Put in a suspended floor..with ventilated void below....problem solved.

[@fabtis1962]

J'ai eu, dans un cas similaire, le même questionnement que le vôtre (et dans une region trèsproche de la vôtre). J'en suis arrivé à la solution suivante : une dalle en ciment MAIS qui n'est pas solidaire des murs en pierre pour ne pas que l'humidité remonte par les murs. La dalle s'arrête à 10cm des murs et l'espace intersticiel est comblé avec des graviers qui permettent à l'eau de s'évaporer avant d'atteindre les murs. Cela fait 5 ans et, pour le moment, tout me porte à croire que cette solution était la bonne.

[@zie9171]

Pardon, pas Francais. What did you put on top of this slab and gravel? I have a cellar (in my French house) the floor is tommettes. But there's damp on the walls. If tommettes were replaced with gravel 10cm around perimeter, would it help? One wall is below street level.

[@fabtis1962]

Je n'ai pas mis de revêtement de sol sur cet espace en gravier, mais je pense qu'il est possible d'envisager d'en mettre (s'il est poreux - comme la terre cuite). Les tomettes en terre cuite me semblent adaptées. En revanche : je pense que si vous couvrez ces graviers, il faut ajouter un drain ventilé tout autour sous les graviers en contact avec l'extérieur et il ne faudrait pas faire les joints des tomettes sur les dix derniers centimètres le long des murs. Tout ce qui est sur la dalle ciment ne pose pas de problème particulier.

[@zie9171]

​@@fabtis1962 merci beaucoup monsieur!

[@TheRenovationProject]

Solution intéressante ! Merci.

[@stevejohnstonbaugh9171]

The answer to your question is - a limecrete floor is not worth it. Second point: What is the situation on this floor with headroom? Do you need more? That would be the only reason to remove material from inside the foundation. 3) Keep in mind that you can run power lines under the slab to avoid having to chop channels in your stone foundation. 4) Because you have severed the old floor along one common wall, no moisture can wick beyond the french drain. 5) Were I doing this job, I would dig a deep sump in the wet back corner into which all of the water from the back of the house and below the slab would drain. I would install an automatic electric sump pump and run the discharge through your solid pipe to daylight. Connect the solid pipe to the sump pit as an emergency overflow. This sump pit will, over time, dry out that entire corner - including the wall that is now wet and the well in the backyard. 6) What is the Relative humidity level throughout the "barn" as it stands now with the windows and doors closed? 7) What is the relative humidity in the house with the new roof and flashing? How do these numbers compare? 8) Your analysis, in my opinion, is sound and unbiased. Limecrete adds no value in your situation and in fact, may make humidity worse. So spend the differential dollars on a through the wall heat pump and airhandler that will dehumidify the interior air and remove the redundant electric radiators. 9) Opening up your current living space into the "barn" will roughly double the square footage that must manage (breathe & preocess) the humidity produced by activities of daily living. 👍

[@CasbahD]

"A concrete decision." You made a punny! Thanks for the laugh!

[@TheRenovationProject]

😂Thanks!

[@bighappyhotgood]

Another option to consider- yes, the damp in the floor will not be able to penetrate the concrete slab effectively and will migrate to the edges where it will climb up the walls- so mitigate that by leaving a 'drainage' channel of gravel, maybe up to 12 inches wide, around the edges and top that with limecrete, so the moisture can wick away before it reaches the walls? The centre floor can then be concrete.

[@warrenmusselman9173]

I would put in a hydronic heated concrete floor - preferably heated via a boiler and hot water, although it can be done electrically. That would entail leveling the floor, installing a vapor barrier and foam insulation as a thermal break between the ground the the concrete slab. On top of that, you have various choices for a finish floor although my choice would likely be something like saltillo tiles. This solution keeps ground moisture out, provides a very thermally efficient heating system with a lot of thermal mass. Once you can isolate all that ground-source moisture from the interior, then the idea of addressing the human-presence caused moisture via ventilation becomes much simpler. One issue that concerns me with the building is the seemingly random window locations and lack of windows on the garden-side and on the side of the building. Plainly what window locations there are were for a building configured much differently than it's current use and they're not conducive to cross-ventilation during the warmer months. I'm concerned that the rendering on the front of the building may be moisture impermeable. The side and back of the building are plainly in need of re-pointing, so going with lime mortar for that will be a net plus in terms of allowing the building to breath, but I am concerned about some of the render I've seen inside where you demo'd the bathroom is cement instead of lime mortar. You may need to put in some sort of active ventilation system or just put in a whole-house dehumidifier in the end.

[@TheRenovationProject]

Hi. Yes, windows are random, another reason we have put a couple of Velux on roof. I agree about the rendering on the facade; something we may deal with much later on.

[@joachim.charleshogg4728]

Always good to hear your thoughts, on the subject of humour, don’t give up your day job and keep up the good work. Regards

[@baladesaufildeschemins6955]

Je regarde vos vidéos car j'ai une maison qui pose problème aussi au niveau de l'humidité. J'ai pu observer cette humidité dans deux contextes différents : 1* la maison était inoccupée depuis une année et plus et l'humidité était massivement situé en bas des murs car la maison est en partie enterrée comme la votre. 2* la maison était occupée depuis quelques mois en automne et en hiver et l'humidité se retrouvait en haut des murs, autour des cadres de fenêtre et sur les parties de mur moins épaisses donc plus froides. (mur en pierre poreuse avec enduit plâtre traditionnel) Pour le cas 1 (sol en béton de ciment et mur en pierre poreuse (grès) plus chaux comme mortier) l'humidité était liée au ciment sur les murs (enduits) qui rendait l'évaporation naturelle impossible. La correction a été de supprimer le ciment sur les murs et de laisser respirer pour toutes les parties enterrées. Ces parties ne sont pas isolées (mais ce n'est pas grave car sous terre) et couvertes de boiseries décoratives qui laissent l'air circuler. Je classe cette humidité comme une humidité structurelle (venant du sol et remontant dans les murs). Pour le cas 2 c'est encore en cour de travail mais disons que supprimer les chocs thermiques a déjà aidé à diminuer le problème et ensuite rétablir une ventilation naturelle à l'aide des conduits de cheminées a aussi aider à corriger le souci ... Ce n'est pas encore parfait mais j'avance. L'humidité est ici liée, comme vous le soulignez à l'activité humaine (vapeur d'eau dans l'air), donc n'est apparue qu'après avoir emménagé après les travaux. Pour le cas qui vous concerne et la vie à la maison, l'aération est une chose a prendre très au sérieux car il faudra évacuer chaque jour l'équivalent de se que vous apportez et plus si vos murs sont fait pour respirer aussi. Dans les temps plus anciens, ce souci ne se posait pas car déjà on ne vivait pas a 20°c, les fenêtres étaient des passoires a l'air tout comme les portes et les cheminée à l'âtre étaient de véritables siphons à air ce qui fait que la vapeur d'eau ne pouvait pas poser de réel souci. Aujourd'hui si on souhaite se passer de VMC (ce qui est mon cas) il faut vraiment réfléchir a tout le circuit de circulation de l'air du bas vers le haut pour que l'humidité sorte (détalonnage des portes, conduit avec grilles, petits ventilateurs ponctuels et automatiques dans les pièces très humides, point d'entré d'air extérieur) A noter que des plantes peuvent aider a capter l'humidité ambiante même si c'est anecdotique en volume. Maintenant pour parler de votre dalle ciment ou chaux on a deux cas possible. Soit c'est de la chaux et l'humidité va s'évaporer de partout dans la pièce (si le système de drainage sous la maison reste correct car je part du principe que l'eau de ruissèlement est gérée et qu'il est question juste de gérer le résiduel) ; soit c'est du béton a base de ciment et l'humidité trouvera son chemin prêt des murs sur une hauteur de moins d'un mettre si ceux ci sont respirant (c'est mon cas actuellement) Dans ce second cas je pense qu'il est impératif de soigner le bas des murs pour les laisser respirer et que la pièce soit assez ventilée donc pourvue d'une prise d'air extérieure tout en conduisant l'air "humide" facilement vers une ouverture haute d'évacuation. Ici, sur les murs, l'usage de chaux est INDISPENSABLE. Notez au passage que ce n'est pas pour rien que les maisons anciennes avaient souvent des boiserie en bas de mur sous les cimaises ;-) Je ne pense pas personnellement que la dalle de chaux soit une solution parfaite car elle oblige a gérer les sols de façon perspirante y compris au niveau du revêtement de sol sur la dalle et cela coutera une petite fortune pour un bénéfice qui n'est pas évident si on a correctement traité les remontés capillaires dans les murs. On peut noter aussi que concernant le bâti ancien il n'est pas forcement pertinent d'amener les murs à un niveau d'humidité très bas car les liants utilisés autrefois contenais parfois des argiles qui fonctionnent très bien uniquement si ils conservent un certain niveau d'humidité. A côté de cela, je sais par expérience (travaux sur les monuments de France) qu'il est préférable de gérer "lentement" ce genre de problème, comme vous le soulignez dans votre vidéo votre grange n'est plus une pataugeoire car vous avez drainé le sol autour et a travers la maison ce qui était la première phase importante. Si vous avancez et que vos bases de murs ne se dégradent pas après une mauvaise saison alors on peut imaginer que le souci est déjà en parti réglé et qu'il convient juste de ne pas trop accentuer le problème de façon irréfléchie et a ce niveau dalle de chaux ou de ciment ne devrait pas être d'une grande différence. Bien sur je connais moins votre maison que vous et rien ne remplace une vue sur place et même de vivre dedans pour bien sentir le problème mais, me concernant, la dalle ciment ne me choquerait nullement si, comme j'en parlais plus haut, les murs sont en capacité de gérer l' exedent d'humidité ET que la ventilation naturelle est bien réalisée. Cordialement

[@chrisdavies6272]

Exactly!!! You put that in a way that is totally understandable, well done 🙂

[@vrvrhm8438]

I have bing watched all your videos. I like the way you describe your construction project. I also like your dry British humour, it's quite similar to my humor. Then I gasped in shock when you showed me the styrofoam and water damage on the toilet and bathroom walls. In the 20th century, when cement and concrete construction came into vogue, all the old tried-and-true construction methods were to be forgotten. I think this trend has been Europe-wide. From the 1970s, as a result of the energy crisis, they started building airtight buildings and old, healthy houses were destroyed by doing energy renovations, in other words, they started using airtight plastic in the construction of houses. The ventilation systems were also blocked with plastic. As a result, new and old houses became moldy and rotted. And now they are being demolished because they are too unhealthy for people to live in. Even entire concrete apartment buildings are demolished because they are uninhabitable due to mold. Have you watched Make. Do. Grow -channel in KZbin? (kzbin.info/www/bejne/gabViHyep5yNqLc) There was big damp issues in their old Portugese stonehouse. The damp issue was because of cement/concret and no drain system among other things. They decidet to put their floor lime, hemp and sand mixture. They had also a big damp issue in their back yard, and they are going to get rid of the big earth sement and stone embankment behind their back door. You have big rock problem in your back yard. How much would it cost if you wanted to get rid of that rock? What else should be done to get rid of all the runoff in your backyard? I'm not an expert in construction at all, but I suggest you leave a concrete slab on the ground, level the sand and build a proper gravity air conditioning/ventilation system in the house above the concrete slab. Above the sand, you can build a limestone slab or a limestone-hemp-sand slab. Remember to build a proper gravity air conditioning system for the whole house, in every room, to get rid of all the moisture that is created by people's living and activities. Good luck!

[@TheRenovationProject]

I am optimistic that when we have ventilation installed and eventually turn up the heating we will see a vast improvement overall. Cheers.

[@davidarenal3043]

Nice reflection and job, but anyway if you have already a concrete slab the final floor could be a suspended floor where in between concrete and floorboards you have a ventilation chamber. It is just a suggestion.

[@normanboyes4983]

I love how you philosophically analyse the situation. I agree with your conclusions. I think there are essentially two problems: 1. Penetrative moisture which you are well on the way to controlling with the new roof and routing groundwater drainage. For the ground floor now I think the next steps is tanking with a heavy duty membrane to prevent moisture rising from the ground, then say 100mm PIR then a wet UFH system. 2. Internally generated moisture is just a fact and has to be managed continuously and a well designed MHVR system is the best way to go. Any other solution will just not cut it.

[@chrisdavies6272]

ive come across the same dilemma's in my lifetime and from my experiences, follow LOGIC and your gut feelings! Except for the syphon effects, water/moister will find its òwn level, now that the issue is dealt with outside there wont be the amount of water ingress climbing the walls, so! Membrane and Concrete floor is the way i would go! Ive been binge watching you channel as from yesterday and this episode is as im writing this comment, it may transpire that when im up to date with your progress your decision will have been made? Please dont dwell too much on decisions as this will drive you insane, yr both doing a great job 😛

[@david.thomas.108]

I think you have your answer and a concrete floor with a damp proof membrane underneath is the way to go. No need to dig up the old floor and that’s also the advice of others who renovate in the area.

[@jennichristie5264]

Hubby grew up in a 400 year old house in England where floors had been lowered over time as human heights increased in the generations, so floor closer to water table and house in similar situation in a slight valley dip and inside levels lower than outside levels. He’s saying (after I described yr issues) that concrete will create moisture problems but limecrete will reduce those and you can offset the damp floor situation by using natural floor surfaces like polished brick or clay tiles that allow the water to evaporate. The only moisture trouble they ever had in their house (that had polished brick everywhere on top of the historical limecrete) was where someone had put in a cork floor in one room which didn’t breathe. He described his mother’s term of a little whale that used to spurt water into the room thru the floor! You can put rugs down on natural flooring as moisture evaporates especially if natural fibres, but not carpets. You don’t want the wicking situation into the walls as damp walls will normally go to mould if they don’t dry out immediately and breathing in mould will cause health issues in relatively short space of time. Not certain abt the slab you have underneath. Wondering if drilling holes at intervals will help like someone else suggested. Or take professional advice on that in relation to the stability of the house. Perhaps cld do small sections at a time if you need to address it. Good luck!

[@stevewoodw]

I was thinking of the levels of humidity in the house when the floor's down - I've got a dehumidifier and standing it on a crate or box with a water container underneath so the overflow has somewhere to go would help keep a lot of the moisture under control. If you do find that the moisture levels rising or want to keep them under control while you're away, leaving a dehumidifier on does use quite a lot of power but you'd have a better solution in place. You need to have a good assessment completed of the moisture coming through from the front as well. There's big appeal to having a DPC below the floor to help keep the moisture under control whatever you choose to have in place.

[@CatherineH.-gf7mm]

Yes. because it will help with the damp issues too

[@robine916]

Check out Make. Do. Grow. They did extensive research for their Portuguese farmhouse limecrete floor. They are incorporating their ground floor into their living space and had lots of moisture issues they had to deal with. 💕

[@BeardedSkunk]

I was convinced by the argument of a German eco-channel that actually did present some older recommendations (maybe from the 1950's) on how to heat insulate your home from the inside. The argument was: that the material you double onto your walls just needs to wick the moisture. So that whenever moisture gets into your wall, then it can wick to the inside of your wall and evaporate there. Since you rarely have 100% moisture in the air of your home, it allows wet walls to dissipate the moisture back into the house. Of course, as you said, walls also get the moisture from the air from inside your home, but that's okay as long as they can lose it again. Id say you can still win some with a lime floor on top of the hidden concrete base as it wicks the moisture to a bigger area and maybe up the walls to evaporate. you maybe shouldn't tile the floor or put big wall blocking furniture in the damp corner you showed today. maybe an electric dehumidifier and / or floorheating would also be prudent in your situation. Anyways, as you showed you do get some additional moisture in that corner and putting a concrete floor there will decrease the evaporation area and limit it to the walls only with a narrow gap were all the moisture below needs to wick through untill it can evaporate. This may keep the walls below floorlevel permanently wet or at least more moist as with a lime or clay floor ... or maybe brick with lime mortar, I'm sure there is some material other than concrete that you like and that is breathable i.e. wicks water.

[@BeardedSkunk]

I can see the argument that with too much water and wicking materials, you wouldn't want a floor that's always damp or even muddy with real wet lime or clay. So you'd go for concrete, but then you have to find some solution for your walls, so they can stand wet feet without losing structural integrity. Maybe rebuild the lower portion with concrete mortar, so it doesn't matter. but maybe its easier in your situation to go with breathable and try to limit the water ingress from the outside.

[@drooplug]

As a test, you could cover the floor with some plastic to see what happens. No matter your choice, you need to handle the moisture. The limecrete will allow moisture to fill the entire home. This puts everything on the floor at risk of too much moisture and you probably have to be careful about the type of floor you install and any rugs. If you do get more moisture in the walls from a concrete wall (I'm not sure that would be the case), you will have to handle the moisture there. But, I think you need to do that anyway. Your walls will always be subject to the moisture from the outside. And you will have to have a system in place to protect whatever wall finish you decide on.

[@Der_Einstein]

I would advise you not to leave the concrete floor in there. It was too much work for me at the time. Now I have the problem in the corners. As you rightly point out, the humidity comes mainly from living in the house. However, a certain amount always comes through the floor and walls. That's not a big deal if the moisture can get out again. In the past, the cellar floors were simply made of rammed clay. Very good for storing fruits, potatoes and vegetables. This layer of clay ensured enough moisture in the room and too much moisture is absorbed again. Concrete absorbs moisture very poorly and releases it even more poorly. There was a video here on KZbin in which someone soaked various lime cubes and a concrete cube in water (until no more air came out of the cubes) and then dried them again to their original weight. The lime cubes were dry again between a few hours and 2 days. The concrete took over 20 days. In addition, clay and especially lime are very alkaline, which means that the spread of mold is very low. Maybe that's why you don't have much mold on the actual walls. I now rely heavily on lime, even though it takes 15 months to harden properly (and unlike concrete, it absorbs a lot of CO2). Consider how much your exterior walls have already begun to deteriorate. This will last for a while, but try to keep the walls dry. It's best without cement, as it also attacks the stones along with the water. So when it comes to lime, always make sure that you use natural hydraulic lime (NHL). The best mixture for soils is 3 parts sand (different grain sizes, which gives more stability) and 1 part lime.

[@troyboy4345]

I think an old building needs old living methods (ventilation, natural heating methods/flue, open fire, drying clothes in the fresh air, water diversion etc) as does a new building (forced/exchanged heating methods, drying your clothes in a sealed machine to ventilate out, gas heaters to balanced flue, water pumping station, concrete foundation structure etc etc) ... so in summary, your thought process maybe has a mix of both in it's analyse, something of an interesting topics tbh, nice work btw

[@Jurraqueando]

An option would be to make a chamber in the floor, since it is seen that the interior is lower than the floor outside, I would create a raised floor by making a chamber to which I would allow ventilation from the outside so that the little humidity that comes out in the interior of the chamber was ventilated, I don't know if you understand what I'm trying to say. A greeting from Spain

[@peterburley2086]

Going back 100-150 years most London houses had no real dpc in the walls they had suspended wooden floors over a natural soil surface with air brick ventilation. Is this an option worth consideration?

[@stan546]

They used Slate within the brick work which acts as the DPC layer, they still work today and are found in most houses from that period.

[@EssGeeSee]

I have said before - that you should build a lean-to roof outside over that wet corner. It would be transparent and come down to within a few inches of the ground on the ‘well’ side. Thus stopping the rain and drying out that corner.

[@chrisdavies6272]

It will never dry out using this method, as it is water coming off the land therefor being continual!

[@otofoto]

Concrete with sheet underneath will push all damp to walls. Bad idea. Concrete also is colder on touch.

[@eriksolie511]

My recommendations (for what they're worth) is concrete slab, but put some extra bucks into the moisture barrier prep. Big return for low investment on that part of it. Good ventilation for whole house is second. Specific type/system is irrelevant as long as everything gets vertilation, especially bathroom & kitchen area.

[@tcjnr82]

I live an old stone cottage it had no slab in one room just a raised timber floor. Which was rotten and I replaced it. I'm considering digging out the concrete in the other rooms. It's tuff to know what's best to do when your battling with damp. The raised floor works really well now. Dry warm and ventilated

[@davidstorm4015]

Given your circumstances, my thoughts would be to go for a concrete floor, then insulation and an underfloor heating system. We have this in our Victorian stone built detached house, which has a similar wall construction to your property. It's been in 8 years now and has been fantastic, we have had no damp issues since installation, despite having had many issues before it was fitted. Also, regarding your interior damp, what you have to do is to keep the inside temp above the dewpoint, so that condensation does not occur. You will find that you will not have damp issues with a concrete floor so long as your house is kept warm and has appropriate wall treatment on the inside. Also, I made a comment on one of your other videos about your chimney(s). Don't cap them off, they are an important source of ventilation and also you can use them to fit a log burner or to have open fires, both of which are great in a building like yours.

[@TheRenovationProject]

Hi. Yes, we did not cap off in the end. Left one open for a wood burner (in the future) and the other has had a ventilating cover put on. Cheers.

[@amayastrata4629]

What one person did on their renovation was to ensure that the stone walls had just lime mix between the stones. They then put in a damp proof membrane on the floor with concrete base but leaving the edges with a gap and that is filled with lime mix. It then allows the walls to breathe and dry. I’m assuming that if the concrete floor that is there already just has the edge removed from the wall then do the same and the walls can still breathe and dry. No way an expert though. Just been watching others consider a similar situation.

[@RS-qp4bp]

If you are concerned about structural integrity I suggest using an additional concrete slab with metal rebar core drilled into the foundation of the house along with a grid pattern of the same rebar embedded in the concrete slab. I would consult a structural engineer that specializes in old stone structures. Good luck in the contest.

[@markcoleman2312]

Water needs somewhere to go. It’s not about the moisture produced within the building , it’s about the ability to get rid of it. If more is produced than can escape it becomes a problem. Cement traps moisture, lime allows it to move. If you could create a vented air space between the old and new floor I don’t think you’d have a problem in the future.

[@paavo2525]

In finland common under concrete floors are single stones like 6-16mm, on dust or sand, cuts off moisture going upp to the floor. Stone walls needs some heat from inside to breath out that moiusture A small woodstove is effective to ventilate out bad air trough chimney. That pipe issue i corner is a problem that had to do something before.

[@stephenprocter9424]

If you think the moisture is coming from you, then ventilation is the key.

[@denisshavaliev1849]

Level the floor with sand and compact it, put vapor barrier and foam insulation. The final layer will be the heating pipe with 5 centimeters of the concrete.

[@mihalybalogh9123]

Regarding the floor, your concern should be about the distance of the floor level from the water level below. If it's sufficient, concrete, crawlspace or limecrete just does not matter. I would get a wall moisture meter. That would tell a lot.

[@jestempies]

The biggest difference to our mold problems was made by mechanical ventilation. We have had an air pump with heat recovery module installed, and it's been a night and day difference. From what I understand, the way old houses were built they were not supposed to be air-tight at all. You've had leaky windows and doors, you've had stoves and fireplaces that pulled out air trough the chimneys. I'm not sure there's a more modern way to have a house like that without providing explicit ventilation pathways.

[@stevegregson4357]

Plus unless it’s always ventilated and you have a heat source such as a log burner no matter what you do it will be or damp of course

[@TheRenovationProject]

Log burner is part of the plan. Cheers.

[@julias-shed]

Are you going to put insulation in the floor? I think that will act like a vapour barrier? Also you can get heat recovery extractor fans which are fairly cheap and are pretty efficient might be worth looking at 😀

[@colsi7228]

Had you considered a chemical dpc for the external walls and laying a timber floor raised up from the concrete floor you mentioned by brick piers (with Dp membrane)? Just a thought

[@paulwalker2777]

It seems like you've got more questions than answers,im sure your viewers will give you some answers,good luck in choosing one,then fingers crossed its the right one,for you its a conundrum for me its fascinating,🏴󠁧󠁢󠁥󠁮󠁧󠁿👍

[@andymccabe6712]

Ha!...the problem with viewers advice is....there will be far more answers than questions.....!!!

[@Welgeldiguniekalias]

CONCRETE, of course! Water would just get trapped under any tiles or floorboards, otherwise, meaning you will be quite limited in your flooring options if you go for the lime stuff. Plus you are letting water vapour INTO the house from below, which seems like a bad idea. Edit: The moisture produced by people living in the home is supposed to leave through ventilation. I don't see how a permeable floor is going to help you there. It's a job for trickle vents and perhaps mechanical ventilation.

[@livingladolcevita7318]

problem as I see it we expect old houses to perform like modern houses. Old houses had coal/wood fires and naturally vented moisture, yes not very efficient heat wise but people years ago were used to the cold and perhaps one central fire was enough. They wore more robust clothing and were more active.

[@KateKoger]

Have you heard of the Heat recovery ventilation systems? We are aware of the Restoration Couple installed them in their cabin build recently. Might be worth considering putting some of these in your home?

[@RogerHooke]

Concrete floor as you have concrete bellow already but the walls need to be lime even if it means chipping out what's there already, if you have concrete on both you will not allow the house to breath enough & stones sweets, have the problem currently in an old stone build building in Wales that was cement pointed many years ago, always damp. I'm planning to chip out all old pointing from the walls and re-do with lime but missive job tried many other things and didn't work, only option left, don't repeat my problem and concrete walls you will regret it but floor yes with membrane then insulation bellow this will stop more damp rising adding to the internal damp problem !

[@richardfearn6638]

You could fit a Vent-axia PureAir Home is designed to eradicate condensation and mould from the home. It reduces the risk of health issues in the home by improving indoor air quality and quickly eradicating conditions that could lead to mould growth and associated health issues such as asthma and itchy skin. The unit reduces humidity in the air, curing condensation and creating a healthier indoor environment.

[@justdna4385]

Your house project reminds me of Laura Kampf's house and the Scottish Chainmail house. Different water problems though.

[@drooplug]

On the topic of where the moisture comes from, the difference between. The outside and the inside is light and airflow (and heat). That's why you get those concentrations of mold. In the case of your home, you have a lot of ground water and a humid climate. That is a huge source and needs to be mitigated. It seems you've made a lot of progress on that front by redirecting that ground water. You are correct that human activity in the house also generates humidity. I wouldn't say one matter more than the other because they both need to be mitigated. It will be easier to mitigate the human cause because you can do most of that with an exhaust fan over the stove and one in the bathroom. But keep in mind that when you runs those fans you pull in humid air from the outside. From my reading of building science, it's better to construct a building where you can control the moisture instead of leaving it up to natural processes.

[@bertrandhuet]

Bonjour, As tu reflechi a enlever la dalle béton seulement en périferie , a 1 mètre des murs.

[@TheRenovationProject]

Merci, idée intéressante.

[@stevegregson4357]

Very damp in fact wet snowdonia barn Perforated drain pipe circulated around floor and to outside dpm 4 inch insulation another dpm and finally 4 inch concrete been down 5 years all good👍

[@zlatahume3134]

Well yes if you planning on lime you should remove all cement, lime is mainly for breathing and do you need it on the floor as you will insulate , that is more question for using it on the walls so it allow any residual moisture to escape😊

[@PeterLee-zn3jl]

Barns humidity can be high then low....occupied housing needs humidity....esp during winter...heat will create motion of humidity...... ..hmmmm

[@pakiw2]

As I found in non "English" sources There is mixture of both, lime and cement based mixes. And it's used as slab for floors. If price is no consideration, I would choose that, and pour over existing one. If price and willness is considered. I would just fill 15 centimetres of gravel and on top reinforced slab 15 cm thick. Old one is already there. And as it's seen drain is working, nothing dramatic is happening, only that corner needs sorting.

[@custino22]

same house like you. I don't live in for moment. I don't heat. mechanical ventilation in bathroom and maybe in another room is a recommandation with concrete slab and with a limecrete slab, too. for the choice of concrete or limecrete, I wonder like you, since a long period. in winter, my non isolated ceiling is covered with water : lot of condensation. so if there is a lot of condensation, I guess there's a lot of humidity in my clay floor, even if it does not show. so in my case, for the wall protect, maybe limecrete slab would be best option. and humidity will go out with a mechanical ventilation.

[@save9624]

If you have the necessary depth I would go with a ventilated floor with "igloo", build above the existing concrete slab. The floor that you build above the ventilated igloo part will have all the proper vapor barrier.

[@stephenprocter9424]

If you need facts & figures, how about contacting a university professor in the UK? He will probably be able to point you in the right direction for them.

[@brucef]

If you’ve not seen it then kzbin.info/www/bejne/ZojLq6Wwh9F1o5I might be worth a watch when considering rubble filled(? Or are yours just single rock?) walls and how to deal with walls that are going to be damp ongoing. Two products, one from Germany and one easier spray on one from Italy mentioned - both permitting moisture transit without growing mould, but being insulated. That might help your floor decision too, decide where you will deal with the moisture and which covering products need to be tolerant of it. A dry/sealed floor and permeable walls might be easier, and a smaller problem.

[@zagzig]

If you have the height i would put a hydronic heated concrete floor

[@Anderzander]

Would you really need to take up the concrete slab ? Could you not just break it in situ ?

[@matthewjordison]

You guys should think about a heat pump to heat home. Cheaper to run and its on all day. It's eradicated damp and mould in my home.

[@timhull8664]

Ask Roger Bisby at Skill builder.

[@johnwade1095]

Neither. Suspended block and beam allows evaporation across the entire floor area. A slab pushes water up the walls. Ventilate the underfloor space with snorkel type air bricks. If you get a crossflow of air, it will remove a lot of water. I like the 3m 9322 mask. If you're leaving the lower slab in, a couple of feet of wall exposed to airflow under the floor will do a lot for you. Do you not have a bathroom extractor and cooker hood (not charcoal type, but venting through the wall)?

[@paulaspinall919]

I like that solution. You are achieving the same ventilated air space as you would with a suspended wooden floor on dwarf walls.

[@vincentput]

Indeed either you build and live in the old way OR you modernize the building fully to live a modern life. As said in the comments; concrete floor insists on having a DPC in the wall. Especially in a wetter temperate environment. Also ventilation should be enhanced when closing all natural gaps

[@lnwolf41]

Most of your moisture was due to that weeping pipe, and all the water draining through it from the back yard. You fixed your outside water problems. It sounds like if you can provide a constant flow of dry air inside, venting the water vapor from the bathroom and kitchen outside, you should be okay. You could always do an inside french drain. bottom line is what is cost of each, and how durable will it be?

[@gaijintendo]

I am certain there is a lag, but you are getting to the last chance to reconsider the pipe being perforated. I remember the video, but I can't remember what the logic was with that. Regardless, watching with keen interest.

[@TheRenovationProject]

I replaced the original perf pipe with a solid drain and installed a separate French drain (can't remember which video it's in). No more water coming in from that original perforated pipe. 👍🏼

[@raytalbot5890]

But won’t the conditions change in the flooring & the walls when you have heating in that part of the house?? What will you do about ventilation?? 👍👍🇬🇧🇬🇧

[@TheRenovationProject]

Yes, conditions are changing already. Ventilation is on the 'to do' list. 👍🏼

[@matthewjordison]

What about a suspended floor. You can even do an insulated suspended concrete floor

[@RalvyBourgoin]

Hi when you say that you have mold building on the inside off the house and you believe that it's human activity that is the cause. Well the cause of the humidity causing mold comes from underneath the basement slab. You wouldn't believe how humidity can travel up through concrete and rendering your inside home humid, the solution is blocking that humidity from travelling up inside your livable space, the solution is if you live in a rather warm climate and you don't need insulation, just put plastic membrane all over the basement floor and cover it with concrete . Or if it's cold and you want a warmer house, put the membrane and put a sm Styrofoam 1 inches or more depending how cold it gets.,or if you have a good budget you gets spray foam on the floor 3 inches of polyurethane the one that dries in 3 seconds, with polyheurethan you don't need the plastic membrane because the polyheurethan is a vaper barrier, and you pour your 3 inches of concrete directly onto the polyheurethan, and know you wont have hany more moisture in your house. Believe me moisture goes wright through concrete you need a vaper barrier to stop it. And if you put plactic you take the thicker one and you make sure to tape all the seems to make it air thight. I wish you look it up. I had the same problem you had and now it's solved. Good work

[@john_ace]

I can give no answer to the concrete vs. "limecrete" question. I am not really sure that "limecrete" was actually used as flooring material. In our "wash-kitchen" there was originally a slate-stone tiled (very thick tiles) floor with about half a meter of sand on a 1.5m foundation of clay. That room had no cellar underneath but has the same foundation as the rest of the house. That floor was later dug up, the sand and part of the clay was removed. Then a wooden floor on brick-columns was erected. The room was no longer used as a "wash-kitchen". Personally i would lean towards a concrete slab. Maybe with floor-heating installed? In regards to the human-factor to the moisture problem: I have mentioned in a previous comment that an active air heat-exchanger could help a lot to maintain warmth but taking in fresh air. As previously stated: relative humidity is ... relative. If very humid air is heated, it seems to loose humidity. 90% rel. humidity in 10 deg. C. turn to 52% rel. humidity at 18 deg. C. and 46% at 20 deg. C, just by heating. The vapor concentration stays at about 8g/m³. If you take the humid air from outside and heat it up with the air from the inside, you can get extremely dry climate in winter. In the summer the problem is condensation since we usually have colder air inside than outside. The moisture from the outside will shed water when cooled. The shedding of water is one of the problems you mentioned: warm humid air comes in contact with cold walls and sheds moisture. That is the reason for reducing cold-bridges when renovation or building. Insulation the Walls on the outside is a way to keep the walls warmer than the outside. This is not a perfect solution since most outside-insulations reduce the transport of moisture through the walls, creating new problems. One of my friends has a damp cellar and built himself a simple ventilation system. It turns on when the outside-air is less humid than the air in the cellar. There are some additional limits for highest and lowest humidity but essentially it works like described. It did reduce mold to the point where he could actually paint the whole cellar and redo the floor without issues.

[@TheRenovationProject]

I am optimistic that when we have the ventilation system installed and heating turned up we will see a vast improvement.

[@john_ace]

@@TheRenovationProject I think that (especially) the new roof and all the other improvements will add up. I doubt that your big problems will just vanish but they will most likely turn into manageable chunks in the long run.

[@arosenberger87]

The concrete would have to come out if you do a limecrete floor. It would create a barrier between the native soil and the limecrete and it would absolutely trap moisture. As for the concrete, you would probably be better off with concrete, with a vapor barrier... But also punching holes through the concrete slab that exists to allow flow of water down into the soil. You may find if you continue to have water issues a sump pump system may be needed. I would not completely remove the concrete unless it was heaving the soil above it.

[@Daytona2]

yeah... Half & half. Clearly. The fact that it's performing well in the wettest conditions for decades is a triumph 😊👏 The renovation organisation you've found sound like the experts as long as they're fully aware of your situation - the amount of water flowing towards your house. They must have advised people in similar situations so perhaps go visit those clients ? Yup, society can be an echo chamber. Go with the evidence, ignore everything else.

[@dalehowey6095]

Are you familiar with the American Family in Italy renovating an old stone house. They have dug down several feet and are creating an air space (may be mandated by building codes) that is ventilated to get rid of moisture. Their house is also built on a fairly friable shale base on the side of a mountain. Here's their KZbin channel: www.youtube.com/@RaisingVoyagers/videos

[@TheRenovationProject]

Thanks.

[@gca259]

Suspended floor with air brick type ventilation?

[@TheRenovationProject]

No room for air bricks unfortunately. 40cm Stone walls and the interior is below the exterior ground level :(.

[@gca259]

Try 'periscope' type wall vents, adjustable for differing ground levels and wall thicknesses.@@TheRenovationProject

[@justdna4385]

Clay or brick are also other options

[@justdna4385]

Did some searching, not clay

[@EssGeeSee]

Much as I would love you to go the Lime route… Even ChatGPT plumps for Concrete - ChatGPT: Choosing concrete over limecrete for the floor of a stone-built house with an existing concrete base provides structural stability and durability. Concrete offers a higher compressive strength, ensuring longevity and resilience in heavy-load environments. Its uniform composition minimizes the risk of differential settling, crucial for maintaining the integrity of a stone structure. Additionally, concrete provides a seamless transition from an existing concrete base, promoting cost-effectiveness and efficient construction. The material's widespread availability and ease of application make it a practical choice for ensuring a robust foundation, addressing the specific demands of modern living while complementing the established strength of the stone-built structure. Blah, blah, blah…

[@otofoto]

ChatGPT has never lived in a house. You don’t need all this durability in a simple floor as if driving a tank in there. Concrete is too cold for flooring.

[@johnthomson1579]

My contribution to the discussion is to ask you if you are over thinking the issue. I enjoy your cogitations but I hope the issues are not becoming obsessive so that you cannot se the wood for the trees. On the face of it, a concrete floor, if mistaken has greater consequences. A lime-crete floor may prove to be no great help but has fewer unwelcome consequences. I think, if water is present, I ‘d rather know about it and deal with it than bury it below concrete and not really know what it is doing. If water is present and comes to the surface through a lime-crete floor you can then put in place mechanisms to deal with this. At least you know about the issue and can address it. If the issue is buried beneath a concrete floor it may be some time before the problems manifest themselves. I’d take the step with least drastic consequences. Yet, I would add, whichever decision you make is not ‘wrong’.; don’t allow it to distract and prevent sleep.

[@TheRenovationProject]

Great comment. I do need to keep my cogitations in check sometimes.

[@ingo_8628]

Concrete is the way to go, the floor to the earth shouldnt breath. When your house is stable, you can dig at the outside to waterproof it, if your walls are wet.

[@michlblacksmith]

Maybe experts in this field can help you - they have dealt with similar stone buildings in a similar wet environment - kzbin.info/www/bejne/sJ6mgZWoodCCq6csi=ZSHTKNlhkXE1aIVf - it for sure is a tricky question. According to their expertise, the floor should be able to breathe. They also talk about the water handling around the house. Good luck

[@stihl3826]

Looks bone dry so I agree, suspended floor and ventilate.

[@timcorso6337]

Yes it is YOU and the way you under heat your house (from the humidistat video) 14 degrees C is too cold. Your house is always near the dew point hence cold walls around reveals and windows causes condensation and mildew. I would go concrete since you already have a concrete sub floor. Also you are making/have made lots of changes to management of moisture inside and out. May be you should wait and see how the house responds to the changes before trying to nail every avenue. You might be wasting your time and money

[@JamesColeman1]

Is this the Proust project? 😂

[@mariokajin]

You have two major issues and some minor ones. One is that you (the house) don’t have any proper foundation and water and thermal separation between the foundation and the exterior walls. The second one is that your house doesn’t have any rendering. The minor ones are no forced or natural ventilation, non finished drainage at the back of the house. If that damp wall is the dividing wall between you and your neighbor then you should solve that too. If you can solve the mentioned above then concrete or limecrete is not the issue.

[@andymccabe6712]

You, my friend ...are FAR too arrogant and over-confident in your pronouncements..... .....this is ALWAYS a recipe for failure or enforced compromise... ...be aware....!!

[@mariokajin]

@@andymccabe6712 Please don’t cancel me. And I was just stating the facts and pointing directions which could improve the status of the building and his life.

[@TMonist]

To be frank. You've now spend a year thinkin on the moisture topic and you still have some questions that about the fundamentals. I think your time is now better spend getting a professional come up with a plan. Once you get a proper and complete plan, you can stop putting energy in pondering and put it into getting the house done. That, or do a couple more years in studying moist managment in houses and not enjoy living in it. I'm saying this as a fellow overthinker

[@TheRenovationProject]

Noted! Thanks. : )

[@avisitorhere]

The thoughtful reposes of you thinking are not helping the video. Lime or concrete and the considerations are a good question but that makes for a 10 minute video at best. This is mostly filler.

[@sinnombre5466]

insufferable