How feasable.. Floor Job.

[zoothorn]

Hi chaps,

 

been meaning to propose this idea, for your expert opinions. An idea gaining traction as my build 'experience' does. 

 

Ok. My 1830 welsh stone cottage is a 6.5m x 5m rectangle. Low ceiling. Onto this main "shell", are 3 extentions, only 1 having insulation (2019). The other two 1970's extensions, are ontop (2 beds). And a ground floor addition (WC, kitchen).

 

The huge overbearing issue is cold, in the main rectangle/ largish sittingroom. I also have the same issue in the two 1970's extentions: a camera showed just 1" of PIR, & none upstairs with 6" cavities behind plasterboard leeching cold loft air down.

 

Now, I cannot feasably redo the upstairs extention ( without ripping out all pB & redoing with thick PIR), nor the ground floor extention (without removing all kitchen & WC fittings, excavating floors & laying 100mm PIR). So forgetting these two extentions (I don't sleep in either bedroom too.. & my kitchen & WC will always be unbearably cold. I Lump it).

 

The one feasable room is main stone sittingroom 6x5 "shell", which I use having my 8.5kw stove in. It's so cold I run it at 375*F for 3hrs.. & back of room only achieves 16*C (my couch remains cold, as does my head, legs, back.. even a hottie on my back, hat & scarf on). Infuriating. PIR-lining the walls' interior? No, due to character loss, & space loss. 
 

So. The only option is excavate the main floor, is my thinking, & either A) add 100mm PIR, concrete cap it back to same level. Or B) add PIR -&- underfloor heating/ the whole hog idea.
 

So firstly: is excavating & redoing either way.. a feasable job prospect? I have no clue.

 

The main problems afaict: 1) I don't know if there is actually any PIR under this old floor as it is: daft to redo it & it makes no difference. 2) If it doesn't have (or say has 1" at best) how do I know the cold isn't 90% pouring in via the side walls instead, & so I'd be flogging a dead horse for zilch.

 

Thanks for reading, Zoothorn.

 

 

Edited December 8, 2022 by zoothorn

[zoothorn]

As you can appreciate, there's alot if character to the inside walls. And it's not hugely wide either as it is.

 

 

 

 

[markc]

Insulating a cold floor makes a massive difference, my mother in law’s house was cold and the kitchen was horrendous, always felt damp and musty. Drilled a couple of test holes in the floor and found concrete on top of clay and ash. She wanted a new kitchen so timing was great, dug out, added DPM and 100mm insulation with a 100mm concrete top (corbelled foundation prevented going deeper). Topped off with a slate floor and the kitchen is now the main room for anyone, no changes to heating or anything, just made a massive difference

[Onoff]

7 hours ago, zoothorn said:

only achieves 16*C

 

Ooh, totally tropical!

 

I've 175mm of insulation under my bathroom floor, it's made a huge difference in there... 

 

[Radian]

1 hour ago, Onoff said:

I've 175mm of insulation under my bathroom floor, it's made a huge difference in there... 

You're supposed to put a little heat into the room as well though 🙄

Seriously - aren't you worried about burst pipes in there or is the water off?

[Onoff]

4 minutes ago, Radian said:

You're supposed to put a little heat into the room as well though 🙄

Seriously - aren't you worried about burst pipes in there or is the water off?

 

F*** it, let 'em burst. Might convince SWMBO we need to start doing things round here my way rather than her mental attempts at papering over the cracks. 

 

She won't  buy into my ideas primarily as it's my idea. Menopausal madness. 

[Roger440]

9 hours ago, zoothorn said:

Hi chaps,

 

been meaning to propose this idea, for your expert opinions. An idea gaining traction as my build 'experience' does. 

 

Ok. My 1830 welsh stone cottage is a 6.5m x 5m rectangle. Low ceiling. Onto this main "shell", are 3 extentions, only 1 having insulation (2019). The other two 1970's extensions, are ontop (2 beds). And a ground floor addition (WC, kitchen).

 

The huge overbearing issue is cold, in the main rectangle/ largish sittingroom. I also have the same issue in the two 1970's extentions: a camera showed just 1" of PIR, & none upstairs with 6" cavities behind plasterboard leeching cold loft air down.

 

Now, I cannot feasably redo the upstairs extention ( without ripping out all pB & redoing with thick PIR), nor the ground floor extention (without removing all kitchen & WC fittings, excavating floors & laying 100mm PIR). So forgetting these two extentions (I don't sleep in either bedroom too.. & my kitchen & WC will always be unbearably cold. I Lump it).

 

The one feasable room is main stone sittingroom 6x5 "shell", which I use having my 8.5kw stove in. It's so cold I run it at 375*F for 3hrs.. & back of room only achieves 16*C (my couch remains cold, as does my head, legs, back.. even a hottie on my back, hat & scarf on). Infuriating. PIR-lining the walls' interior? No, due to character loss, & space loss. 
 

So. The only option is excavate the main floor, is my thinking, & either A) add 100mm PIR, concrete cap it back to same level. Or B) add PIR -&- underfloor heating/ the whole hog idea.
 

So firstly: is excavating & redoing either way.. a feasable job prospect? I have no clue.

 

The main problems afaict: 1) I don't know if there is actually any PIR under this old floor as it is: daft to redo it & it makes no difference. 2) If it doesn't have (or say has 1" at best) how do I know the cold isn't 90% pouring in via the side walls instead, & so I'd be flogging a dead horse for zilch.

 

Thanks for reading, Zoothorn.

 

 

 

Is the floor currently concrete?

[Onoff]

@zoothorn  I feel your pain. This is my lounge with the probe sat on the floor:

 

 

Then with the same probe hanging off the light fitting. The probe is about 5' from where it was on the floor.

 

 

 

Quite a big issue here is the suspended wooden floors. Cold air just comes in through the air bricks and up through the uninsulated floors, through plug sockets, around skirting etc. 

 

Gutting sat here with a beanie on and under a blanket KNOWING what needs to be done and having the ability to do it.

 

It all needs gutting back to the dirt at floor level, the joists in the ceiling and the bare brick/block walls.

 

SWMBO just won't buy into doing it yet will happily burn through oil and sit moaning how cold it is.

[Pocster]

[Onoff]

4 hours ago, pocster said:

 

Ah, the master of floor jobs speaks!

[Big Jimbo]

I think a first good step would be to have a very good look at any small gaps, skirtings, windows, pipes through floors etc, and seal them all up with a flexible gun mastic.  When i did my daughters house, she had a massive thing about ants. I sealed up everything, even tiny holes to ensure that there would be no access for the marching monsters. It made a huge difference. All those small holes add up. I'm willing to bet that in her semi those small holes added up to a square foot. Imagine cutting a hole in your wall a foot square to the outside !  There was a recent post by somebody on here complaining about a draft from the plinths in the kitchen. I bet if they took the kitchen out, the draft gaps behind would be huge. Not a bad place to start, and costs very little. Good luck Zoot.

[zoothorn]

19 hours ago, markc said:

Insulating a cold floor makes a massive difference, my mother in law’s house was cold and the kitchen was horrendous, always felt damp and musty. Drilled a couple of test holes in the floor and found concrete on top of clay and ash. She wanted a new kitchen so timing was great, dug out, added DPM and 100mm insulation with a 100mm concrete top (corbelled foundation prevented going deeper). Topped off with a slate floor and the kitchen is now the main room for anyone, no changes to heating or anything, just made a massive difference

Morning markc, thanks for this.

 

So did you do the work? Interesting results indeed. I bet she didn't have 2ft stone walls though & loft cold filtering down, past the beds above ( via the horrendous 6" cavities behind all/ both bedrooms' pB), & down hitting the edges of her kitchen ceiling tho! 
 

Can you tell me what her kitchen walls construction is like? I mean the point being, if you knew beforehand that she had 100mm PIR in the walls, & say a reasonably ok room above too, then you knew almost certainly after your test drill hole & finding concrete floor upon clay, that THIS was definitively the obvious weak link.

 

With mine you see, like a boat taking on water ( but without being able to do a bubble test to determine where the hole, or holes are) I cannot determine --where-- the cold is primarily leeching in via. If I knew the answer to this, & knew confidently it --was-- to a decent degree the floor.. I'd prolly have cracked on by now.

 

A very useful reply though, adding to my sense of confidence I am perhaps, ploughing the correct furrow with this idea. In retrospect, underfloor heating is out as an idea, not material costwise but simply due to running costs.

 

Thanks, Zoot

 

 

[zoothorn]

11 hours ago, Roger440 said:

 

Is the floor currently concrete?

Hi Roger, I dont think I've had a post from yourself before:- so thanks for reading my spiel, & your input.

 

This is the nub question. Alas I don't know at this stage. But.. it just sure -feels- like there's simply no insulation under the concrete floor.

 

BUT a fly in the ointment ((maybe) thus: my builder found tiny evidence of flecks of a blue membrane, at edges of  this floor, suggesting it's -not- the original 1830 floor (which would have been just sat upon clay).

So, when this dpm was put down is unknown, as is whether any PIR was put down during this job too. Thx Z

[saveasteading]

Draughts first, yes agreed. pull the furniture away from the walls and get down close where you can feel the cold air coming in. (you won't feel warmer air going out, which might still be happening).

I have never use smoke sticks but that seems worthwhile.

 

Floors lose most heat near to outside walls, when built solid on the ground, as the earth has quite a bit of thermal resistance. In your house though, probably most of the floor is within 3m of the outside.

 

Insulating the floor is the most efficient, as you get the immediate benefit of warmer feet.

 

That house probably had a loose brick floor, if anything, originally. It may still be there, built over, in which case removal might not be too bad. 

BUT beware that digging out internally will expose the foundations, which are likely very shallow....but can be overcome with care.

[zoothorn]

@Onoff Hi there, autumn greetings ( stunning day here, & -2 or so last night around midnight, & had cabin at 21*C at 11.30pm, albeit with a fair bit of effort, but passed the tricky sub-zero test pretty well).

 

Well we're in a similar boat re cold. That alone helps my thinking tbh, as you understand the frustration.

 

I too know -some- of the places cold is ingressing my main room, & such a big job curtails fixing:

So as said, loft air 'cocoons' the bedrooms above, in the big cavities behind plasterboards on 3 sides each room ( divider wall between no issue), so like "one big rectangle of cold" air sat down -upon- the outside edges of the ceiling below. Then I'm so constrained to fill it, that all I've been able to do, is expandy foam in two places only (where you could see up almost to the loft standing in the main sittingroom). But the majority of this "cold rectangle" is just above the 1st floor, where the chipboard floor meets the edges of the lower walls ok... preventing any access to stuffing with anything. So cold just lies in a perimeter rectangular ring, just above my head.. apart from two 2m gaps Ive foamed 'closed'.

 

So no cold loft air anymore -directly- leeches down & into main room (when I moved in you could feel cold air coming into sittingroom edges via the 2x 2m gaps!).. but.. just does just sit menacingly around edges. The dividing floor is thankfully thin enough to not think full of the same cold air really. Nothing I can do here.
 

Zoot

[zoothorn]

@Big Jimbo & @saveasteading morning chaps,

 

thanks for these suggestions: yes, I have done everything I can on this front, before coming to this last resort 'floor big job' idea. Really thoughrally sealed everything I can. It's leeching in though so hugely, from well I hope mostly the floor should I proceed with the grand plan, that addressing these minor ingresses you hint at.. is akin to a drop in the ocean. Its made no discernable difference. 
 

Even sealing the tangible cold air ingress gaps (you could even hear it whistling!) at the edges of the main room ceiling gaps-right-up-to-loft... made no discernable difference.

 

So there's such such a HUGE ammount of cold entering the room, that the stove hasn't a chance of winning the battle ( or rather it could IF its run at super-hot 400*C for 3 hours using two huge baskets of logs, & warping parts of the stove in the process) running it 'normally', nor has stuffing edge gaps, doors, etc etc.

 

Thing is first up, in an ideal world, is determining -where- the cold is entering via. But unlike a boat where you can bubble-test & find the ingress holes... with air you can't, as far as I know, do such a test to determine where the cold air is mainly leeching in from.

 

[Roger440]

2 hours ago, zoothorn said:

Hi Roger, I dont think I've had a post from yourself before:- so thanks for reading my spiel, & your input.

 

This is the nub question. Alas I don't know at this stage. But.. it just sure -feels- like there's simply no insulation under the concrete floor.

 

BUT a fly in the ointment ((maybe) thus: my builder found tiny evidence of flecks of a blue membrane, at edges of  this floor, suggesting it's -not- the original 1830 floor (which would have been just sat upon clay).

So, when this dpm was put down is unknown, as is whether any PIR was put down during this job too. Thx Z

 

Id guess theres almost certainly no insulation under it. Just like mine was.

 

Do you not have any damp issues with the wall? Given the age and lack of a dpc, id expect them to be a bit damp., especially if its got a DPM under the concrete.  Damp walls are cold walls. Though a lot of stone used in welsh houses is completely impervious to water.

 

We broke ours out, used foamed glass as the sub base and insulation layer, so minimal excavation depth abd also to resolve the issue of moisture going sideways to the walls. Our walls are brick and like sponges. Damp doest start to cover it! 

 

And fitted underfloor heating while we were at it. transformed it. The walls remain uninsulated, but are completely dry now. Sits at 21.5 c all the time and a humidity of 55-60%. Obviously we got rid of all the sources of incoming air too.

 

If you are going to do anything, do it properly, do it once. We did everything ourselves except the actual slab. But knowing the humidity will tell you a lot about whats going on. My guess is that it will be quite high. Prior to the work, ours was always over 90%. At that level its always going to feel cold.

 

Having just bought a welsh stone cottage with a concrete floor, it looks like i get to do it all again

 

 

 

 

 

 

 

[PeterW]

@zoothornhow much insulation in the main house loft space ..??

[Jenki]

If you do the floor, why not consider a floating timber floor, more insulation no concrete so a little cleaner. You will need to ensure the base is flat. But 150mm of PIR (OR 200MM EPS) would have a great impact. You could still add UFH.

[zoothorn]

22 hours ago, Roger440 said:

 

Id guess theres almost certainly no insulation under it. Just like mine was.

 

Do you not have any damp issues with the wall? Given the age and lack of a dpc, id expect them to be a bit damp., especially if its got a DPM under the concrete.  Damp walls are cold walls. Though a lot of stone used in welsh houses is completely impervious to water.

 

We broke ours out, used foamed glass as the sub base and insulation layer, so minimal excavation depth abd also to resolve the issue of moisture going sideways to the walls. Our walls are brick and like sponges. Damp doest start to cover it! 

 

And fitted underfloor heating while we were at it. transformed it. The walls remain uninsulated, but are completely dry now. Sits at 21.5 c all the time and a humidity of 55-60%. Obviously we got rid of all the sources of incoming air too.

 

If you are going to do anything, do it properly, do it once. We did everything ourselves except the actual slab. But knowing the humidity will tell you a lot about whats going on. My guess is that it will be quite high. Prior to the work, ours was always over 90%. At that level its always going to feel cold.

 

Having just bought a welsh stone cottage with a concrete floor, it looks like i get to do it all again

 

 

 

 

 

 

 

Hi Roger- just noticed your mid wales too.. & another stone cottage-? Well well, this is very useful to know. I wonder where you are.
 

Anyway, what I thought as my builder years ago -did- seem to find evidence of a blue bit of placcy @ edge of floor.. was & this was his opinion, that there -was- evidence of a dpm. This surely implies that the floor therefore-isn't- the original. And if so, then the implication further, is that there -might- be some PIR underfoot. I'd suggest it depends if it was a pro or amateur job (if pro PIR is surely more likely, even if a " 1" token gesture" like I know my ground floor walls are graced with before the 2" cavity). 
 

Damp. Even with this slim evidence of a dpm, yes I do get a bit of damp evident at edges: a dry black powdery residue I have to wipe away ( lowest 1ft on one wall) not bad at all really this/ not 'damp odour bad' here. But, I do get more in this room, upon a cupboard wall: open this tiny cupboard & there -is- wall moisture, plus a mild damp odour too. And another lesser floor edge area. So some thankfully " liveable-with " evidence of damp within the WALLS, moreso than the floor. Perhaps also suggesting a dpm -is- in place even if a bit shoddy.

 

SO. One benefit I would hope to gain from my floor redo-masterplan.. is to clear up some, if not the majority if in the walls, of this damp. A bonus. But not the priority reason for the idea. Cold cold cold, is.
 

Thanks, Zooter

 

 

Edited December 10, 2022 by zoothorn

[zoothorn]

21 hours ago, PeterW said:

@zoothornhow much insulation in the main house loft space ..??

Hi Peter, I have a "normal dose" of so-so 80's orange fluff, plus, 2 years ago a grant for another layer: a good 250mm extra added ontop, & perp to the joists: by a welsh "loft-monkey" in 1 hr whilst his monkey-mate smoked a fag outside. 
 

So I think 'adequate' to answer your question, to rule out I think this being one of the main factors. Its's more the loft air getting down & filling behind all 4 plasterboard sides below the loft. IE imagine one big bedroom, just with a thin divider between making it two.

[zoothorn]

17 hours ago, Jenki said:

If you do the floor, why not consider a floating timber floor, more insulation no concrete so a little cleaner. You will need to ensure the base is flat. But 150mm of PIR (OR 200MM EPS) would have a great impact. You could still add UFH.

Hi Jenki, thanks for your very good suggestion, & I did this in my extension so know the process/ caber floor. 

 

The only fly in the soup: I'm a boring audiophile & need the mass of concrete below my 2 speakers.

 

But, I wonder if I could incorporate two 400x400 gaps ( my spkr positions ) afterwards.. & fill up with concrete? Hmm interesting. Cheaper surely.. no need to spend on a Pro Co to pipe in concrete, as I'd imagine the top layer part of the job would need. 

 

 

 

 

 

 

 

 

[zoothorn]

@Onoff I'll take a temp reading at different points in my mainroom tonight, like yours. The floor lowest 2ft defo feels like a pool of cold. 12.5*C for you though? Jeepers I thought only my bad luck encountered such temps.

 

At the moment.. 6.8*C in my mainroom typing this, hottie on my back. Freezing nose & hands. No heating on. Im just about happy enough, spinning a few records even so: I'm so used to the cold it's just 'normal' after 6 yrs.

 

[My cabin in comparison last ev.. 28*C ! Super toasty, t shirt & shorts, real luxury: & 0*C outside, at the most].

[saveasteading]

Do you have any spare headroom at the doors, so you could build on top without bumping your head?  probably not.

 

Any extra insulation, even 10mm will make a difference.

 

My hunch is that the previous custodian has poured a simple concrete slab over the previous brick, including a dpm.

 

How to find out? you could cut or bore a hole and see what you find. Infill with sand /cement back to level, but paint the inside and base of the hole with bitumen to maintain a dampness barrier.

If you do, you it would be worth going through the underlayer until you hit earth, to see what is there, and how deep.

 

[Onoff]

My kitchen floor is about 4 or 5 inches higher than the rest of the house. The previous owner had a damp issue so laid a plastic sheet down and poured a slab.

 

When I cored out the "new" slab for the breakfast bar leg it had the old floor lino under the slab.