Old cottage with Concrete Floor

OldHouse

I have recently purchased a old stone 2 storey cottage. On one 1/2 of the house there is and suspended timber ground floor which is rotten and is going to be replaced. On the other 1/2 of the building the timber floor was removed and a 4 inch concrete screed was poured on loosely filled rubble and stone. The floor is already breaking up in several locations so I'm going to have to bite the bullet at take it up too. My question is this, considering the age of the building 1910 and the construction stone rubble walls approx 500mm deep I would like some advice on what breathable insulated floors I can use in this building. Most of the information i have read on old building are steering me towards a breathable floor, but i'ts hard getting information on exactly what type to use. I should also mention I was hopping to install a underfloor heating system, but not sure if this is viable for a breathable floor.
I have had the house tested for Radon, and it's well with in the acceptable safe limits, so there is no need for vapour barrier to prevent this. I have also noted that before I removed the skirting boards in the half with the concrete floor they were completely rotten compered with the ones over the timber floor which where only 1/2 rotten, so I'm guessing it was something to do with pushing moisture into the walls from under the floor.
Would putting in a Underfloor Heating (UFH) also prevent the the natural traveling of moisture from below and also force excess moisture into walls?
Sorry about the long post I hope it makes since.

BryanF

Insulation with ufh: should at least achieve 0.15w/m2k (circa 150mm PIR or 250mm EPS)
Rising damp: electroosmosis
I'm all for breathablity of the structure but would suggest that concrete is the easiest subfloor if your going with ufh

What you do with the walls is where IMO breathablity is important. Start with lowering the external ground min 150mm below internal floor level. Then look at breathable insulation methods- search hemp-lime, wood fibre, calcium silcate, and ask yourself could you afford a breathable Ewi system to reduce the risk of interstitial condensation and internal surface mould.
next, how are you going to vent this under flooring heated room? Great big wall vents, or by mechanical means..

labin_86

Hi There,
Im going through a similar situation myself, Im no expert but Ill tell you what Ive done!
Our house is a hodge podge of buildings, some parts date back to the late 1700's. Most of the house has suspended timber floors. The kitchen had a poured concrete floor (8inches thick!) on top of some rubble and a pretty uneven ground level beneath that, it used to be a stables so we had bits of wall and all sorts under there.
We have had huge problems with wet and dry rot throughout the house mainly because of concrete render being applied to the exterior of the building, an extension being built badly that blocked the air vents and a ground level that was much higher outside than inside.
What we ended up doing was removing and digging out all of the old concrete floor as it was cracked and uneven, this took a bit of time.
We had wanted to go for underfloor heating but we were advised against this by our plumber as he said for the cost we wouldn't feel huge benefit to it, especially in a kitchen which should be pretty warm when Im in here cooking
We will have a stove in the room and two rads too.
We laid hardcore and sand, levelled it, then laid a damp course and raydon barrier then we used kingspan insulation and taped all of the gaps to make it airtight. On top of this we repoured the concrete floor.
In addition to this we are lowering the ground level outside the house by 12 inches (our ground levels are crazy...) we are also using lime render on our exterior walls.
Throughout the rest of the house we will have suspended wooden floors, all of the joists have been repaired and replaced with all rot being removed and all of the wood being treated with chemicals to avoid this from happening again. We removed any old insulation and we are installing new vents to ensure proper airflow.

The Kingspan website has some useful information about insulation with diagrams too. I'd recommend taking a look, try looking into the ground bearing concrete slab. Ive been assured by my conservation architect and builder that this is all good and should keep the room well insulated and prevent any further issues.

OldHouse

BryanF wrote: »

Insulation with ufh: should at least achieve 0.15w/m2k (circa 150mm PIR or 250mm EPS)
Rising damp: electroosmosis
I'm all for breathablity of the structure but would suggest that concrete is the easiest subfloor if your going with ufh

What you do with the walls is where IMO breathablity is important. Start with lowering the external ground min 150mm below internal floor level. Then look at breathable insulation methods- search hemp-lime, wood fibre, calcium silcate, and ask yourself could you afford a breathable Ewi system to reduce the risk of interstitial condensation and internal surface mould.
next, how are you going to vent this under flooring heated room? Great big wall vents, or by mechanical means..

Thanks for your reply. I agree that concrete is the easiest option, but Not sure if its the best option. As i mentioned already there was originally a poorly fitted concrete floor in 1/2 the down stairs and there was a notable difference in the dampness around the skirting above the concrete floor. And a lot of the information on reinstating old floors suggest putting in natural breathable materials. Linecrete etc.
I found a few interesting articles last night about this and one of involving using a Recyled foam glass Gravel looks very interesting indeed.

It won't let me post URL as I'm a new user but it was on the worldwideweb.lime.org.uk/products//limecrete-and-sublime/labc-registered-sublime-limecrete-floor/

I'm sure it's not the cheapest option but if it complement the existing stone wall it looks like a better option.

I also have to insulated the walls internally and I am looking at using approx 100mm Hempcrete between a stub partition that is going to be employed to support a new first floor as the existing one was red rotten. Don't like the idea of fixing joist back into a possible damp wall again!!

OldHouse

labin_86 wrote: »

Hi There,
Im going through a similar situation myself, Im no expert but Ill tell you what Ive done!
Our house is a hodge podge of buildings, some parts date back to the late 1700's. Most of the house has suspended timber floors. The kitchen had a poured concrete floor (8inches thick!) on top of some rubble and a pretty uneven ground level beneath that, it used to be a stables so we had bits of wall and all sorts under there.
We have had huge problems with wet and dry rot throughout the house mainly because of concrete render being applied to the exterior of the building, an extension being built badly that blocked the air vents and a ground level that was much higher outside than inside.
What we ended up doing was removing and digging out all of the old concrete floor as it was cracked and uneven, this took a bit of time.
We had wanted to go for underfloor heating but we were advised against this by our plumber as he said for the cost we wouldn't feel huge benefit to it, especially in a kitchen which should be pretty warm when Im in here cooking
We will have a stove in the room and two rads too.
We laid hardcore and sand, levelled it, then laid a damp course and raydon barrier then we used kingspan insulation and taped all of the gaps to make it airtight. On top of this we repoured the concrete floor.
In addition to this we are lowering the ground level outside the house by 12 inches (our ground levels are crazy...) we are also using lime render on our exterior walls.
Throughout the rest of the house we will have suspended wooden floors, all of the joists have been repaired and replaced with all rot being removed and all of the wood being treated with chemicals to avoid this from happening again. We removed any old insulation and we are installing new vents to ensure proper airflow.

The Kingspan website has some useful information about insulation with diagrams too. I'd recommend taking a look, try looking into the ground bearing concrete slab. Ive been assured by my conservation architect and builder that this is all good and should keep the room well insulated and prevent any further issues.

There is currently about a 6 inch step between inside and out and this will be about nearly 9 inches when i have installed the underfloor heating. Theres is also old french drawings around the building but I will probably look into redoing them after I have made progrees inside.
Kingspan only seems to do the petrolemum bases insulations which do a great job and relatively inexpensive for new builds. I don't think they are suitable for old conversions. I did read an interesting article on their website last night about breath-ability where they debunk all the claims by other manufactures and conversationalists about the importance of breathable vapor permeable materials.
Seems a bit desperate of them!!

worldwideweb.kingspaninsulation.ie/getattachment/be8de0b1-7575-49f7-b0b7-b755f68b174b/Breathability.aspx

labin_86

Haha! Well we didn't go with Kingspan because of their articles
Its definitely ok to use more modern building materials in an older house once everything else doesn't contradict it (if you know what I mean) so we made sure that the render, ground level etc would all help to eliminate the damp problem.
There is a website called -snip- .ie that we found very helpful and we sourced a lot of our contractors from the site and we also got advice from our local conservation planning officer.
We are also installing french drains, work just started this morning on them!

OldHouse

Thanks for that website I will have a read of it later

BryanF

OldHouse wrote: »

Thanks for your reply. I agree that concrete is the easiest option, but Not sure if its the best option. As i mentioned already there was originally a poorly fitted concrete floor in 1/2 the down stairs and there was a notable difference in the dampness around the skirting above the concrete floor. And a lot of the information on reinstating old floors suggest putting in natural breathable materials. Linecrete etc.
I found a few interesting articles last night about this and one of involving using a Recyled foam glass Gravel looks very interesting indeed.

It won't let me post URL as I'm a new user but it was on the worldwideweb.lime.org.uk/products//limecrete-and-sublime/labc-registered-sublime-limecrete-floor/

I'm sure it's not the cheapest option but if it complement the existing stone wall it looks like a better option.

I also have to insulated the walls internally and I am looking at using approx 100mm Hempcrete between a stub partition that is going to be employed to support a new first floor as the existing one was red rotten. Don't like the idea of fixing joist back into a possible damp wall again!!

You need an arch who understands interstiail condensation and rising damp to advise.
Is the limecrete suitable for underfloor heating? How will you detail the edge of limecrete with insulation up the edges to achieve insulation continuity? Have you considered electro osmosis?

OldHouse

BryanF wrote: »

You need an arch who understands interstiail condensation and rising damp to advise.
Is the limecrete suitable for underfloor heating? How will you detail the edge of limecrete with insulation up the edges to achieve insulation continuity? Have you considered electro osmosis?

Excuse my ignorance, but what is electro osmosis??

BryanF

OldHouse wrote: »

Excuse my ignorance, but what is electro osmosis??

best to Google electro osmosis and rising walls/ rising damp?

OldHouse

Cheers BryanF

BryanF

OldHouse wrote: »

Thanks for your reply. I agree that concrete is the easiest option, but Not sure if its the best option. As i mentioned already there was originally a poorly fitted concrete floor in 1/2 the down stairs and there was a notable difference in the dampness around the skirting above the concrete floor. And a lot of the information on reinstating old floors suggest putting in natural breathable materials. Linecrete etc.
I found a few interesting articles last night about this and one of involving using a Recyled foam glass Gravel looks very interesting indeed.

It won't let me post URL as I'm a new user but it was on the worldwideweb.lime.org.uk/products//limecrete-and-sublime/labc-registered-sublime-limecrete-floor/

I'm sure it's not the cheapest option but if it complement the existing stone wall it looks like a better option.

I also have to insulated the walls internally and I am looking at using approx 100mm Hempcrete between a stub partition that is going to be employed to support a new first floor as the existing one was red rotten. Don't like the idea of fixing joist back into a possible damp wall again!!

Hi, Just reading back over your posts, I think you should keep looking at hemplime floor and if you can satisfy yourself that the UFH will work with it why not. GGBS has been made popular by an 'eco' brand in Ireland, the cement does cut CO2 Dramatically. Hemplime v ecocem in embodied energy, I'd lean towards hemplime.

Edit: just to add, there's several useful sources for hemp lime info on boards.ie perhaps try the boards search engine. Try CAT (centre for alternative technology, Wales) they have some papers on the subject. There are several Irish guys and useful sites just google around.

As regards the old cottage you need to deal with the rising walls, and I'd strongly recommend you seek ventilation advice from several independent sources: suppliers & experienced designers/ architect. think about RH levels and the interstitial wall due point. the wall hemplime must be entirely gripped ti the stone/internal lime plaster, some thought is required with the stud work.

Best of luck on your project.

OldHouse

Hi Bryan

I have also looked into using the Hempcrete in the floor also but I have a niggling concern that if the site is damp that the Hemcrete will never dry out fully from underside at least, and that's a worry!! That's why I'm in favor of the Recyled foam glass Gravel although i have since found another article using Lightweight Expanded Clay Aggregate (LECA) as an insulation material below.
[snip]
either system looks good albeit labour intensive!!
I looked into the electro osmosis and it looks like a good system and seems to do the job!! My biggest concern would be it's something that could easily stop working in the future if so some reason the current was stopped from getting into the wall. I'm also not a fan of any form of mechanical ventilation systems as there is always maintenance and performance issues as the system gets older. That's why I'm trying to build a house that has a decent amount of thermal mass. So i'm not concerned about some hot air escaping out through vents and open windows and the like. You see I live in the house with 5 children and a large dog and whit all the will in the world it's impossible to keep the doors closed any longer than 1/2 hour!!
The Hempcrete looks like a great product and I'm going to try and use it in the walls once I sort of the floors.

OldHouse

Don't know what happened there. Tries editing the posts and it just changed it and left the old ones. Can someone delete the first two!!

TVRV8S

Hi,

I was just browsing and came across this thread.

I am just about to lay a glapor (recycled glass) and limecrete floor with underfloor heating in my 16/17th century farmhouse in England. It's been a long road of archaeology, digging, back filling, moving stone, research and thinking but the mixer is coming on Friday so it's all happening.

I am using the Ty Mawr sublime solution, along with a underfloor heating kit from elsewhere.

The build-up is geotextile membrane, 150mm glapor, geotextile membrane, plastic geogrid, plastic clip rails cable tied to the geogrid, the underfloor pipes and then 100mm of limecrete screed. The edge insulation for the screed layer is cork boards.

The screed uses Ty Mawr's own recycled aggregate rather than LECA, the expanded clay stuff that most limecrete floors use. LECA would, I think, be an insulating barrier to the heating.

If you have any questions, I'll try to answer them.

OldHouse

TVRV8S wrote: »

Hi,

I was just browsing and came across this thread.

I am just about to lay a glapor (recycled glass) and limecrete floor with underfloor heating in my 16/17th century farmhouse in England. It's been a long road of archaeology, digging, back filling, moving stone, research and thinking but the mixer is coming on Friday so it's all happening.

I am using the Ty Mawr sublime solution, along with a underfloor heating kit from elsewhere.

The build-up is geotextile membrane, 150mm glapor, geotextile membrane, plastic geogrid, plastic clip rails cable tied to the geogrid, the underfloor pipes and then 100mm of limecrete screed. The edge insulation for the screed layer is cork boards.

The screed uses Ty Mawr's own recycled aggregate rather than LECA, the expanded clay stuff that most limecrete floors use. LECA would, I think, be an insulating barrier to the heating.

If you have any questions, I'll try to answer them.

Thanks for that Information. Just out of curiosity what sort of U-Value would that provide when the floor is finished. Also Does the Ty Mawr sublime solution guarantee cover using alternative underfloor heating system?
Also have you see these system being used else where first hand or just in articles and case studies??

Cheers

TVRV8S

OldHouse wrote: »

Thanks for that Information. Just out of curiosity what sort of U-Value would that provide when the floor is finished. Also Does the Ty Mawr sublime solution guarantee cover using alternative underfloor heating system?
Also have you see these system being used else where first hand or just in articles and case studies??

Cheers

Hi there,

I'm lucky in that I have few exterior walls in the room that I'm limecreting, so I could achieve a U-value of 0.18 with the build-up of 150mm of glass and 100mm of lime screed. Ty Mawr calculated it all for me - I supplied the room measurements and some additional information and they sorted all the maths out, and the quantities I'd need.

I'm not sure what you mean by 'guarantee cover'. If you mean does it work with electric underfloor heating, then I think you would then just use a limecrete screed with LECA and then put the electric stuff on top of that under your tiles / floorboards. I could be wrong.

If you mean ground/air heat pumps, that's more a plumbing issue rather than a limecrete issue as whatever you use to provide the energy for water underfloor heating, it still needs to be converted into hot water which is then blended by a pump and valve and pushed around the pipework.

I have stood on a sub-lime limecrete floor, and I have had it explained to me when I did a 2 day course at Ty Mawr in Wales in May. I have also had lots of help from them by email and phone. I'm still bricking it though.

If you do their course, you also get 10% off all purchases for a year which is fairly significant savings when talking about tons of material.

Mike Wye is also helpful, and they also do the Glapor glass stuff but call it something different.

I think the benefit of the Glapor over a standard LECA-based floor, where you would use LECA as the insulation layer as well as in your screed (floor slab), is that it has better insulation properties, doesn't need to be coated to stop capillary action, and bears loads better so you don't need such a thick layer for the same U-value or strength. It's more expensive though.

TVRV8S

If you don't understand anything in my post, let me know.

I have been unbelievably frustrated by forum posters assuming you already know everything when they are explaining something. Hardly anyone takes the time to explain things properly.

OldHouse

TVRV8S wrote: »

Hi there,

I'm lucky in that I have few exterior walls in the room that I'm limecreting, so I could achieve a U-value of 0.18 with the build-up of 150mm of glass and 100mm of lime screed. Ty Mawr calculated it all for me - I supplied the room measurements and some additional information and they sorted all the maths out, and the quantities I'd need.

I'm not sure what you mean by 'guarantee cover'. If you mean does it work with electric underfloor heating, then I think you would then just use a limecrete screed with LECA and then put the electric stuff on top of that under your tiles / floorboards. I could be wrong.

If you mean ground/air heat pumps, that's more a plumbing issue rather than a limecrete issue as whatever you use to provide the energy for water underfloor heating, it still needs to be converted into hot water which is then blended by a pump and valve and pushed around the pipework.

I have stood on a sub-lime limecrete floor, and I have had it explained to me when I did a 2 day course at Ty Mawr in Wales in May. I have also had lots of help from them by email and phone. I'm still bricking it though.

If you do their course, you also get 10% off all purchases for a year which is fairly significant savings when talking about tons of material.

Mike Wye is also helpful, and they also do the Glapor glass stuff but call it something different.

I think the benefit of the Glapor over a standard LECA-based floor, where you would use LECA as the insulation layer as well as in your screed (floor slab), is that it has better insulation properties, doesn't need to be coated to stop capillary action, and bears loads better so you don't need such a thick layer for the same U-value or strength. It's more expensive though.

Thanks again, you have being very helpfull. I have 3 external wall on either side of the 2 floor I'm laying so I expect I may need more. But I have the depth anyway without have to excavate anyway so it's not an issue.
In relation to the guarantee I mean does the glapor guarantee once you use an competators UFH system on top. Because I know they have their own system and I taught it was system as a whole including the UFH that had the approval from the councils.
I might book myself in on that course.
Cheers

TVRV8S

As for hempcrete, I have found it difficult finding an affordable supply of hemp shiv (the woddy stalk bits you mix up in your mortar or plaster) in the UK.

The cheapest appears to be Aubiose, sold as horse bedding, which I can get for about £10 for 200 litres.

The stuff sold for lime plaster, if you can even find it, is called Hemcore or similar. This is about £20 for 200 litres, and I believe it's exactly the same stuff.

Both products have the dust extracted.

Ty Mawr sell a hemp lime plaster which I've bought two tons of as ready-mix as I'm running out of time (lime is low temperature intolerant) and money (the right mixer hire is EXPENSIVE).

Anyway, if you were going to do some hempcrete I'd suggest trying the Aubiose if you can get it over there.

TVRV8S

OldHouse wrote: »

Thanks again, you have being very helpfull. I have 3 external wall on either side of the 2 floor I'm laying so I expect I may need more. But I have the depth anyway without have to excavate anyway so it's not an issue.
In relation to the guarantee I mean does the glapor guarantee once you use an competators UFH system on top. Because I know they have their own system and I taught it was system as a whole including the UFH that had the approval from the councils.
I might book myself in on that course.
Cheers

As far as I am aware, Ty Mawr don't sell UFH kits. It's not the business they're in.

They show the underfloor pipes in their diagrams, though, which is helpful to understand it all for someone like me!

It's more the membranes, glapor and lime that is registered with the building authority, not the auxiliary stuff like the pipes.

They are supplying me (and it should have been delivered about now) with:

- lime for the screed
- recycled aggregate for the screed
- fibres for the screed
- glapor
- membranes
- plastic geogrid that goes on top of the glapor that I'll cable tie the underfloor heating clip rails to
- hemp lime plaster
- cork board edging insulation


If you need a very practical course for plastering, hempcreting and laying limecrete, the Ty Mawr course may not be right for you. We didn't do any limecreting, but we did do some pointing with lime and plastering onto lath, then doing bottom (scratch), middle (float) and top coats of lime plaster. It was a great course but more suited to people who know only very little about using lime. There's theory, talking about solutions to various problems each person has, bits of practical work, being taught how to do things by the instructors, seeing how they've restored their house and buildings. It's all very friendly and very well put together, but if you've never plastered for instance, there's not hours to perfect your technique.

Very very nice lunch, and it's held in really beautiful surroundings next to a lake.

TVRV8S

Oh just to give you an idea of cost on a 32m2 floor with the build up I mentioned, the floor materials (including delivery and my 10% discount) was about £2,000.

Add to that mixer hire for 3 days: £360

Wacker plate hire to compress the glapor before laying the screed: about £40

You may need shuttering wood on top if you are laying it over several days. I haven't bought that yet.

OldHouse

TVRV8S wrote: »

Oh just to give you an idea of cost on a 32m2 floor with the build up I mentioned, the floor materials (including delivery and my 10% discount) was about £2,000.

Add to that mixer hire for 3 days: £360

Wacker plate hire to compress the glapor before laying the screed: about £40

You may need shuttering wood on top if you are laying it over several days. I haven't bought that yet.

I have approx 42m2 and I would also need a mixer and compactor but that price was roughly in line with what I expected. I'm not going to lay the Lime crete UFH heating imediately as I going to just put in the sub floor with maybe a shall lime screen. And put in the underfloor heating at a later date after i had installed the structural stud to the inside of the walls and insulated the walls with the Hempcrete. Not done much on reserch into the hemcrete yet as I will not be done until next spring. Its getting a bit late the year to try that out going into damper weather.

watou

I am in Ireland with a single-level old stone cottage that needs the storage heaters removed and UFH installed. Total floor space is 60 sq. m. The bedrooms are raised timber floors, but the rest is lino on concrete slab. The cottage was dry-lined, new roof, new electrical about 10 years ago, but the heating system is worse than worthless.

I am having a terrible time getting the local engineers and tradespeople to give me straight answers about the best build-up for new floors, on which I will then add laminate flooring, and tiles in the bathroom/kitchen.

I intend to heat the water with a 6-panel thermodynamic panel system for heat and hot water.

Since I can't get the locals to give me useful information, are there resources online that you trust so I can educate myself, and then I can just direct the contractor to do it the way I've found is best?

Many thanks for any pointers.

JonathonS

watou wrote: »

are there resources online that you trust so I can educate myself, and then I can just direct the contractor to do it the way I've found is best?

You may find this thread on Boards useful http://www.boards.ie/vbulletin/showthread.php?t=2057481190&utm_source=notification&utm_medium=email&utm_campaign=digestthread

There is also some good info on the Greenspec site http://www.greenspec.co.uk/building-design/ground-floor-insulation/

I find eBuild is also a good source of info, for example this thread http://www.ebuild.co.uk/topic/17076-floor-insulation-build-up/

The insulation manufacturers also have papers that describe in detail how the floor should be built up, and how to prevent thermal bridging.

watou

Thanks VERY much for these helpful links. Much appreciated!

Funsterdelux

I was researching and getting estimates for an old cottage in Cork last year and I got this quote from Ty Mawr for £4,800 pound sterling, it was for a 75sqm total floor area, and the materials (lime, geotextile, geogrid, glapor, aggregate, screed fibres, expanded cork board for edge insulation) 150mm foam glass depth, and 100mm limecrete screed.

That included delivery also.

I have also done a course in using lime in restoration in stoneware studios near Youghal.

OldHouse

Funsterdelux wrote: »

I was researching and getting estimates for an old cottage in Cork last year and I got this quote from Ty Mawr for £4,800 pound sterling, it was for a 75sqm total floor area, and the materials (lime, geotextile, geogrid, glapor, aggregate, screed fibres, expanded cork board for edge insulation) 150mm foam glass depth, and 100mm limecrete screed.

That included delivery also.

I have also done a course in using lime in restoration in stoneware studios near Youghal.

Only seeing this now, so thanks for your considered reply. I think I'm also going to with this option. Probably install the floor when the weather picks up.

BryanF

OldHouse wrote: »

Only seeing this now, so thanks for your considered reply. I think I'm also going to with this option. Probably install the floor when the weather picks up.

Are you still considering underfloor heating? You'll need a lot more insulation depth at least .15wm2k IMO - check the foam glass u-value..

OldHouse

BryanF wrote: »

Are you still considering underfloor heating? You'll need a lot more insulation depth at least .15wm2k IMO - check the foam glass u-value..

Not sure if it's worth the extra cost. Probably get a spec for both.

BryanF

OldHouse wrote: »

Not sure if it's worth the extra cost. Probably get a spec for both.

I wouldn't bother with underfloor heating

Voodoomelon

Just stumbled upon this. I have a detailed blog on how i managed this exact same scenario in my 1820s house in Dundalk.

Same deal, there were concrete floors laid on the ground floor, mixed with original timber flooring, with a multitude of damp problems. Do not go down the route of "damp proofing", electro osmosis or other hocus pocus solutions. Get to the root cause of any damp and tackle it head on.

In my case, concrete was causing massive problems and I had it all ripped out. The limecrete floor has worked wonders and every single section of damp in the house has disappeared.

The ground floor works start at the below link. I'll be happy to answer any questions.

http://georgianrenovation.blogspot.ie/2014_02_01_archive.html

OldHouse

Voodoomelon wrote: »

Just stumbled upon this. I have a detailed blog on how i managed this exact same scenario in my 1820s house in Dundalk.

Same deal, there were concrete floors laid on the ground floor, mixed with original timber flooring, with a multitude of damp problems. Do not go down the route of "damp proofing", electro osmosis or other hocus pocus solutions. Get to the root cause of any damp and tackle it head on.

In my case, concrete was causing massive problems and I had it all ripped out. The limecrete floor has worked wonders and every single section of damp in the house has disappeared.

The ground floor works start at the below link. I'll be happy to answer any questions.

georgianrenovation.blogspot.ie/2014_02_01_archive.html

Thanks for that Information and blog you appear to have very similar issues to what I have encountered. I have uncovered any bones yet!!
If it's okay with you I will send you a pm to pick your brain on a few things?

Thanks

Voodoomelon

Sure no probs.

JonathonS

Voodoomelon wrote: »

In my case, concrete was causing massive problems and I had it all ripped out.

That is a very interesting blog, well done.

Re the concrete slab, how thick was it, and how did you excavate it (Kango?). Any advice on that process - I am about to start taking up a concrete floor in a 1970's house.

Voodoomelon

Funnily enough, it was nowhere near as deep as we thought it would be, only about 8 or 9 inches. Broke up with a Kango in half an hour.

It was probably in relation to the previous owner, who about 20-30 years ago had a small surgery in the back room and probably wanted rid of the wooden floor boards. I'd say soon after the conrete went down, they had nothing but damp problems judging by the lines on the walls, so they cement rendered and then plastered over the lower sections of the walls, compounding it further.

The logic then, and still today to an extent is to "seal" up everything with concrete and sand cement. It may work well on new builds, but its hateful on older houses and causes horrific damage.

Neddyusa

Amazing stuff Voodoo Melon - I just stumbled across your blog and I'm hugely impressed with the quality of your restoration job. Have you moved in yet?
We are currently renovating a 1910 built stone farmhouse (was originally built by my great grandfather) which was constructed with very similar methods. We are aiming to improve breath-ability of the structure to reduce/eliminate damp issues. We have stripped all the 1960s added cement plaster from walls internally and externally and are now re-rendering with lime externally.

Originally, we planned to pour a limecrete floor but due to our tight budget and after talking to some conservation builders they claimed the extra cost over concrete was not worth it because 1. expense of heating the limecrete floor with heat loss to the underlying clay and 2. extra initial expense over concrete. We are now considering a hybrid limecrete floor similar to what you have done with a limecrete boundary of 300mm around the concrete slab. We aim to pour 75mm concrete screed with UFH pipes on insulation over the slab, with limecrete coming up to FFL around the external walls.
This is similar to your own job except you used limecrete for screed.

Are you happy with how your floor has turned out and have you any tips or recommendations??
What were your reasons for going with the hybrid rather than full limecrete floor and was the cost difference significant?

Thanks in advance.
Congrats again on the fantastic blog and all the work involved!

Voodoomelon

Hey Neddy, thanks very much.

Would you believe I've yet to move in fully, but should be in by the end of the year.

I often scratch my head as to why I did a hybrid slab of concrete and lime as the cost difference would have been frig all looking back to do it all in lime. Maybe i was a performance thing, i.e. concrete holds more heat, i'm trying to remember the reason.

At the end of the day, the only difference between the two slabs is using bags of lime instead of cement. Lime is of course more expensive, but not by much considering my floor area wasn't particularly large.

The underfloor works very well, its actually on right now for the first time since April or so as I have a great painter in who requested it on so the fillers work properly. I can't comment on efficiency really as i've yet to have it on at room temperatures for prolonged periods, but I do remember I had just the ground floor ticking over at 13 Celsius all through our very cold winter, just to stop it dropping into single figures and it used about €500 of fuel, so that's pretty poor! But says more about my house than the system itself.

The chap that laid the floor boards on top of the slab in the kitchen didn't leave enough space around the edges so there's a small bit of buckling of the boards, nothing that can't be fixed though.

I've a page on Instagram which is updated several times a week, way more than the blog.

https://www.instagram.com/georgianrenovation/

Your plan sounds good, but the builders aren't 100% right about the loss of hear underneath. Hence why I used the Leca Insufill to insulated between the clay and the line, and then a full Kingspan board under the concrete slab.

Coming along anyways:

Howzit17

Wonderful blog and IG voodoomelon.I’m Reno an old 1910 2 story Irish farmhouse, and have just gone thru the process of removing most of the concrete and drywall ,plastered outside in lime and pointed inside in lime.was going to go the limecrete route for the floor but the man doing the work,specializes in Reno old stone buildings.Suggested this option...hack existing concrete floor and reduce level to 500mm deep, compact base,install dpc and wallplate member,install floor joists and solid bridging,install reclaimed timber floor boards,install glass bottles between sleeper walls,install 100mm sheep wool between joists.
Apparently he done it before with great success.He say’s the bottles was an old thing the farmers used to do for cattle sheds years ago in country areas, was very effective...��*♂️
And since I want to go with reclaimed wood floor versus flagstone he suggested this method.
Undecided which route to go.

Voodoomelon

That's an interesting method, i'm baffled by the glass bottles though, you hardly have a cross-section diagram of the proposed works?

By my reading the plan is to installed a DPC across the entire compacted base, with the joists suspended slightly above and insulation in between? The general idea is to allow the soil beneath to breath upwards, otherwise if you cover the whole area with a DPC, the only escape route for moisture in the soil is upwards through the walls. It was based on this logic that I went the route that I did, not to say that other methods wouldn't work and not to say that this logic is 100% proven, but it makes sense to me.

Removing the concrete floor and replacing with another impermeable installation doesn't make a lot of sense to me.