How feasable.. Floor Job.

[zoothorn]

18 minutes ago, saveasteading said:

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.

 

Hi SAS, no the opposite: I was considering digging down an extra bit to -add- some room height. The ceiling's very low only 1.85m high, it reminds me of HMS Victory with the ceiling beams & wonky walls! Although my kitchen/ WC it leads into would be a step up then, plus front door which leads directly into this main room, would then be a step down from. No, I think keep at same level.

 

The staircase is at one corner of the room though. It's got a bit of charm, but essentially only 'decent-amateur' standard & "agricultural" with 4mm cheap unsightly ply covering the back. It could be an opportunity to renovate it.. but adds a big extra workload, for me. But underneath the 600x600 base step 'square' footprint on the room corner, is inaccessible to excavate without removing staircase.

 

Yup I thought the 1st step might be drilling a hole/ see what's going on. If the basic idea of laying PIR & a caberfloor top is do-able for me (did just this in my new extention last year) the unknown part is the excavation work & especially the depth relative to the shallow foundations. Shallow is known, as they were exposed at the extention build: & one foundation corner 'coin' stone permanently & alarmingly visible outside, due to the extention 1 foot-too-low fiasco (the results of which continue to plague me, in countless ways).

 

 

 

[Onoff]

Slight thread drift but in my kitchen I've considered leaving the wall units in place and digging a big rectangle out of the middle of the floor. Then insulating bottom and sides of the excavated hole, adding UFH pipes and topping off with concrete back to the original level. In effect a big heat store. 

[TonyT]

You don’t say what the floor construction make up is at the moment?

[Onoff]

1 hour ago, TonyT said:

You don’t say what the floor construction make up is at the moment?

 

@zoothorn's floor? I don't think he knows. Like me. 

 

Out of 8 rooms downstairs I have 7 different floor constructions. 

[Roger440]

9 hours ago, zoothorn said:

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

 

 

 

Mine had a DPM too. Straight on the mud. Given what you have told us and posted pics of, id bet there no PIR or anything else to be seen.

 

Just drill a hole through it and find out. 10 mins work and you will have the answer. Im going to do the same on my welsh house soon, just as soon as ive sorted out some more pressing issues. That too has a recentish floor with DPC. Again, i bet it doesnt have insulation. The infra red thermometer says floor temp is 8 degrees.

 

If you have evidence of damp in the walls, you seriously need to reconsider using a DPM. I used foamed glass for this reason. If you have gypsum plaster, that needs to go too. It will stay wet forver otherwise.

 

Though some are a bit hardcore, id take a look at the period property forum. Lots of experience there. Not to suggest there isnt here, but this is more focussed on newer stuff.

 

Im a few miles east of Llandovery.

[Onoff]

11.6 degC in the lounge here when I got up. Sat with a fleece jacket and bobble hat on. When this black coffee I currently have my hands around has done it's thing, I'll need to brave the bathroom 😉

[zoothorn]

17 hours ago, Onoff said:

Slight thread drift but in my kitchen I've considered leaving the wall units in place and digging a big rectangle out of the middle of the floor. Then insulating bottom and sides of the excavated hole, adding UFH pipes and topping off with concrete back to the original level. In effect a big heat store. 

Aha. Good thinking. I ruled out feasably attacking my kitchen (WC is just too tiny to consider this).. but this is the only way then. Interesting. I could only consider PIR tho, as UFH is too costly now to run/ me one person.

 

----

 

Temp readings yesterday: during day ( no heat at all) temp on central low table = 6.2*C.

 

Stove on for 2.5 hours almost flat out from 7pm, room at 10.30pm, on floor middle of room = 13.2*C (only 2m from stove). Top of ceiling middle of room = 20*C (very low ceiling though).

 

Actually this was a much better evening, I had a whole film 10 to 11.30 lying on sofa & reasonably warm, albeit a hottie on my back & hat on. So if I take a mean of the two = 16*C or so, on my sofa (only 1.5m away from stove).
 

But you have to "run the gauntlet" (& a big stove effort) between 7pm - 10.30pm until room bearable.
So in comparison, if I can get the cabin to 20*C in 45 mins, using 1/4 fuel... it almost seems daft using the house in the evening now at all.

Edited December 11, 2022 by zoothorn

[zoothorn]

17 hours ago, TonyT said:

You don’t say what the floor construction make up is at the moment?

As Onoff says TT, I just don't know. My builder picked at a bit of blue placcy once @ at one floor edge, said something about a dpm. 
 

So is the test hole something I can do myself? What size are we talking if so.

 

 

[zoothorn]

3 hours ago, Onoff said:

11.6 degC in the lounge here when I got up. Sat with a fleece jacket and bobble hat on. When this black coffee I currently have my hands around has done it's thing, I'll need to brave the bathroom 😉

You must have some insulative aspect then overnight, to have retained some of the evenings heat. 
 

6.5*C in my mainroon, @ tum height, this morning. I must say it's reassuring to know you can understand my situation Onoff. My old folks, just can't understand. Well just put the heating on then they say, then 

i try explaining that unless this is a jet-powered-level of -constant- heat the idea here, won't work. Let alone a meagre-heat-output ASHP (that I knew couldn't possibly work here, but had installed knowing this full well so can't complain about it's heating ineffectiveness; I will shriek in complaint about infuriating overnight mechanical noise ruining my sleep tho).

 

Zoot

[TonyT]

Can’t believe an 8.5kW stove isn’t heating that room!

 

 

[zoothorn]

On 11/12/2022 at 14:06, TonyT said:

Can’t believe an 8.5kW stove isn’t heating that room!

 

 

But surely you can, after describing no mainroom insulation, it's 2ft 'cold radiator' slate walls, cold pouring in up from floor (Im hoping a large portion of it is, or my job prospect here won't reap great results), the trapped loft air cocooning upstairs big pB cavities & sitting on the perimeter of the mainroom ceiling, & cold leeching in through timber door from uninsulated (bar 1" of wall PIR) kitchen. So much cold must pour down stairwell from upstairs too, also impossible to combat.

 

That I find it a wonder I -can- get an hour of 'reasonable warmth' 10-11pm in the mainroom at all.

 

You can only not understand how my 8.5kW stove isn't heating it ( so much that inside sections have warped with heat- I've no choice but run it flat out).. because you can't have experienced such an uninsulated stone house.
 

The cold was the very reason my predecessor sold it, & why I therefore could afford it ( she snapped my hand off at my first offer you see, a very low figure). I just need to do some careful evaluation, as to how much benefit I might get, from doing the floor.. being the only feasable avenue available to me.

[zoothorn]

Anyway I need to get back on track. I can't know how much effect this proposed floor idea will achieve, so alas I have to simply make a big gamble, if I proceed.
 

Ideally I'd have PeterW or Joe90 for eg, come see my house & all it's cold flaws (clever pun) & tell me in their experienced estimation.. would they go ahead with the gamble floor idea? Not some builder who'd just say "oh yes FAR warmer afterwards" because he has only have himself in mind, ie a straightforward job prospect.
 

So I understand this is a huge gamble, but it's SO uncomfortable & as Im now past 50, the prospect of the cold status quo situation is becoming untennable to live like this.
 

-- So I need to consider how feasable the excavation "lions share" part of the job might be, for me alone.
Or is it maybe more sensible to get a builder to do the excavation I wonder. --

 

Thanks for reading, zoot 

 

 

[TonyT]

You need to get some heat loss calculations done

 

calculation is used for any type of heating system and will take the guess work out of it.

 

 

[TonyT]

A 6.5x5 x2.4m box, with 6 m2of glazing. 3 outside walls , uninsulated floor and roof, solid walls, with outside air temp of minus 3 and internal temp of 21 deg would take approx 11kw of heating, using rough dimplex room calculator, so 8kW stove in a room used properly would lift temps a fair bit.

Edited December 14, 2022 by TonyT

[zoothorn]

7 hours ago, TonyT said:

A 6.5x5 x2.4m box, with 6 m2of glazing. 3 outside walls , uninsulated floor and roof, solid walls, with outside air temp of minus 3 and internal temp of 21 deg would take approx 11kw of heating, using rough dimplex room calculator, so 8kW stove in a room used properly would lift temps a fair bit.

Hi TT, when you say "in a room used properly" I'm not really understanding the suggestion. Are you suggesting here a different solution, not to excavate, but just to get a bigger stove-?

 

I was really needing opinions on the feasibility of the actual work involved in the floor redo idea. I have no idea you see, what an excavation process might be in this case. Whether it's feasable one person could do it. If I could do it. I do know that once this lion's-share portion of the job done.. adding the PIR & even the floor ontop, is acheivable, as I've done it before.

 

I need help on the details, of an excavation of the floor. Has anyone done any kind of floor excavation?

 

Thanks, zoot

 

 

[saveasteading]

27 minutes ago, zoothorn said:

anyone done any kind of floor excavation

Yes.

In the steading we are converting.

We have the advantage of not living in it, and also that the ground is dense sand.

The main concern was exposing the very shallow footings. There are tales of buildings falling down, and this is a real concern.

 

In your case I would work in small areas, perhaps 1m or 1 .5m wide across the room so as to minimise the exposed area of wall. Then you can dig out to the chosen depth, smooth and compact, lay dpm, lay pir, and screed over.

Then move on, taping the dpm at laps.

I wouldn't dig below the footing level. However you could jncreaze the depth away from the wall. Loads spreading at 45 degrees is a decent assumption.

I would also place pir vertically over the edge of the screed. Even 10mm is worth it, but I would suggest 20mm if a skirting or quadrant can cover it.

 

Meanwhile in my own house with solid concrete floors....I have not done this because of the work and disruption involved. I do have 100mm pir in most of the walls though so am not in your position.

 

How thick are your walls?

[Onoff]

18 minutes ago, zoothorn said:

I need help on the details, of an excavation of the floor. Has anyone done any kind of floor excavation?

 

 

As others have said, multiple times it'd be an idea to do a test dig. Yes btw I've done similar in a single room. First clear the room! 

 

 

-Kango the floor:

 

 

-Remove the floor to separate pile outside. Think I shifted about 70 or 80 rubble bags then the soil on top: 

 

 

-Dig down. The depth will vary according to your floor build up/design:

 

 

-Distribute the soil where you can outside. It grows btw. 

 

-Grade the removed floor / break up to reuse as a sub base. I used max 40mm.

 

-Level this off. The paint splodges are where I had stakes banged into the dirt to ensure a constant hardcore thickness:

 

 

-Compact:

 

 

-Blind with sharp sand:

 

 

 

-Lay a layer of 25mm EPS:

 

 

-Lay a DPM. Note there's a 2" thick upstand of EPS around the perimeter. This is to help take up the expansion of the slab when it heats up. (I did too add extra expansion strip).

 

 

 

-Lay PIR min 150mm. Did mine in 2 layers, 50+100, staggered the joints and foil taped:

 

 

 

-Lay UFH pipes, cheap even if you don't use them. I used Polypipe panels but you can staple to the PIR if you put another plastic membrane over the foil face:

 

 

-Lay A142 mesh:

 

 

 

-Lay concrete 100mm deep. I had various areas shuttered off for the part sunken bath and wet room corner. I used "wet" mixed concrete. I forgot to add strengthening fibres to the mix for this! The mesh should negate the need.....I hope. The concrete comes to the height of the expansion/perimeter strip. 

 

 

 

-Tile:

 

 

Ask multiple stupid questions along the way and take years off forum member's lives in the process! 😂

[Marvin]

Damn proper job there @Onoff!  

[Onoff]

1 minute ago, Marvin said:

Damn proper job there @Onoff!  

 

It was alright until the tiling!

 

Tbh, now I've done the one room I'm completely confident to do the rest of the house. Just wish SWMBO would get onboard. 

[Marvin]

Good time to start diggin... in the middle of winter keep you warm. Sure SWMBO can find some buckets....

 

 

[Marvin]

I have deep retro insulated floors in 5 properties ( all with suspended floors) and every one expresses surprise as too how much warmer the floor and rooms feel.  

[Onoff]

23 minutes ago, Marvin said:

I have deep retro insulated floors in 5 properties ( all with suspended floors) and every one expresses surprise as too how much warmer the floor and rooms feel.  

 

Tbh the bathroom did feel nice and warm, even without heating until I punched multiple holes in the ceiling for the body dryer, speakers and down lights. Might be my Christmas mission to make good those areas.

[Onoff]

30 minutes ago, Marvin said:

Good time to start diggin... in the middle of winter keep you warm. Sure SWMBO can find some buckets....

 

 

 

I suggested this. Even that my jobless 23 year old could do the digging etc whilst I'm at work. SWMBO thinks we should wait until Spring.

 

???

[Onoff]

Here you go @zoothorn, my lounge. Suspended timber floor, clay air bricks open to the elements. I've hung a thermometer from the light fitting with the probe midway between floor and ceiling. Just in front of the second "P" in HAPPY. Temperature is reading 20.5degC.

 

 

Then there's another on the pouffe with the probe on the floor. That is reading 13.4degC.

 

So one probe directly below the other.

 

No wonder our feet are freezing!

Edited December 14, 2022 by Onoff

[ash_scotland88]

Been wondering the same for our house. 1930s built.

One quarter(ish) of the ground floor is concrete, even has an air brick and pipe allowing through air to the hallway. This would be done when the great dinning room and kitchen knock downs, through and glazing project happens.

The concrete area is currently kitchen, back hall, pantry, coal store and laundry room. We'd only do the back hall and kitchen areas. But keeping an eye on this thread.

 

As to keep on track, only way to know is a test hole.