Old cottage with Concrete Floor

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.