1930s Floor issue. Seems very soft. How to make it stronger and lasting

[Jonny Vee]

Hi,

Just removed my old T&G plank and at the beginning I though that below I had a very strong Concrete flooring but this is not the case.

I made few trial hole and the drill bits goes in like a soft cream and what come out is a black soil.

the all flooring does not sound very strong and my question is how I deal with that and if this is normal on old houses.

 

[Why Not Indeed]

the all flooring does not sound very strong and my question is how I deal with that and if this is normal on old houses.

I think you're going to have to do a bit more investigation and come up with some more specific questions about your floor if you want some help. Even then, it's worth searching as there are thousands of threads on here and there is bound to be something relevant.

 

[KenGMac]

Gio I, good evening.

What you describe is somewhat "un conventional"

No Joists, flooring laid direct on to a sub base?

The "black earth" you describe? how thick is it? it may ??? be a form of bitumen that material is very black.

I have seen on very, very odd occasions timber floor boards laid direct on to a solid base with no joists or air gaps, the one I recall vividly was flooring laid on to a painted on bituminous emulsion this bitumen had been laid on to an ash base.

From what I could see, it appears that historically the floor had suffered a severe wood rot infestation, and all flooring and joistsw were removed, the Ash imported and flooring laid, on the outer walls there were still to be seen cast iron air vents at very regulat spacing in a masonry [stone] wall.

Are any od the floor boards you are lifting showing sigme of wood rot?

Ken

 

[bobasd]

lift a few more boards and post a pic or two on here - one pic close up & one pic from a context distance.

 

[Jonny Vee]

Gio I, good evening.

What you describe is somewhat "un conventional"

No Joists, flooring laid direct on to a sub base?

The "black earth" you describe? how thick is it? it may ??? be a form of bitumen that material is very black.

I have seen on very, very odd occasions timber floor boards laid direct on to a solid base with no joists or air gaps, the one I recall vividly was flooring laid on to a painted on bituminous emulsion this bitumen had been laid on to an ash base.

From what I could see, it appears that historically the floor had suffered a severe wood rot infestation, and all flooring and joistsw were removed, the Ash imported and flooring laid, on the outer walls there were still to be seen cast iron air vents at very regulat spacing in a masonry [stone] wall.

Are any od the floor boards you are lifting showing sigme of wood rot?

Ken

Tomorrow will post some photos. How thick is I have no idea yet. I drilled with a 10mm drill bits for 120mm and was the same thing as something like black powder. I have attached photos I have at moment on the phone but will make more as I will be removing all flooring.

 

[Jonny Vee]

Here you go more photos

 

[bobasd]

Thanks for the pics.

The latest pics show, so it seems, a different composition of floor material?
Maybe its the light or something but the first pics showed a say "bitumen" mix and the latest pics seem to show a weak cementitious mix?

Were the boards in the first pics damp - were there any white salts on the back of the boards?
Except for pic 6, the floors in the latest pics look to be dry, & so do the walls. Is pic 6 a spill?

What kind of finish flooring do you want?

 

[Jonny Vee]

Hi, Phone battery died and could not make another photo where I removed a brick between the extension side and you can see a thick granulate solid in black colour.

I will upload it tomorrow.

Most of the photos are a little bit lighter and there is a lot of dust that covers or made the black to become lighter.

I will clean up with some water and upload more photos.

On the first photos there was a 18mm stone paving. No white salt on the back of the boards

Pic 6 is wet because I'm removing the wallpaper and this is a spill of water.

I'm thinking to install 18mm engineering wooden floor on 80% of this substrate and the rest (Kitchen) will install some tiles.

I was thinking to extend my hole pit to a 200/300mm to see what below. Just awaiting delivery of drill bits as all shops are currently closed. Is it worth it? I have also dug a trance for a drainage pipe on this flooring.

Walls and flooring seem to be dry and doesn't see any humidity at the moment. Do I have to check with some electronic tool?

On another note. In a few areas, the substrate seems to be a little bit weaker and sounds empty. My idea was to poor 3/4mm of latex or something stronger self-levelling room by room to make it sturdy but I'm here to get advice from you guys that have more experience.

Many Thanks

 

[bobasd]

The least amount of disturbance is probably for the best - no more digging or trenching if thats possible? Why trench a waste pipe(?) into the floor?
That includes interfering with "hollow" areas - leave them alone they've lasted this far.
No need to use any elec meters etc.

You could remove lengths of skirting here and there, and examine the wall behind & the back of the boards?
Wall plaster or render should stop short of any FFL by about 40mm to 50mm higher.

As a test you could seal a small square of poly over any area of the rough floor and wait & see ref any moisture rising up?

The conundrum is whether to seal the surface as a damp precaution before installing finish flooring or no sealing but allowing the floor to breathe more or less as it is? I'm not on site so i couldn't make that call.
Others more experienced and confident than me might say different?

Old neighbour's often have knowledge of previous works in their street etc - heads up calls to local RICS Surveyors or Estate Agents might also yield info about your kind of floor?

 

[Jonny Vee]

I'm going to have a downstair bathroom and have 2 options. Saniflo which I don't really like and dig a trench to bring pipe outside. Could make a straight cut eityh angle grinder without increasing vibration on the substrate.

I'm removing the skirting to fit a new one.

The conudrum is whether to add some sort of screed like latex or something stronger on top of this substrate before installing the finish floor.

I don't know anyone in the area as we are new and I understand most people have recently moved there or are renting.

 

[bobasd]

Will your bathroom have a WC?

 

[Jonny Vee]

Will your bathroom have a WC?

Yes full bathroom

 

[Jonny Vee]

Here you go more photos

 

[Jonny Vee]

Cleaned up the dust with bit of water

 

[catlad]

It looks like an ashfelt floor to me, but not easy to tell as I can't see the whole area. I would leave it alone unless absolutely necessary.