Edwardian house, flooring surprise - not a good one !!!

[bobasd]

Thats great - whatever sweat equity means - well you've got it in spades. A tremendous job of hard work.

Whats the plan now? No air brick pockets from previous vents to be seen but do you now intend to have a suspended floor?
Whatever your plans - come back on here, and just ask if you want suggestions?

 

[ianleon]

Thanks for your kind words.
Its nice to see the condition of the bricks under floor in such good condition.
No signs that i can see that it was ever suspended whilst digging it up.

Am I best to repoint the brick work that was previously under the floor where the mortar has come out ?
If so should I use the lime stuff the rest of the house is in or is there a different one I need as its inside and under the floor ?
I'm weighing up having underfloor heating fitted as it's highly likely i'm going to have to do the same to every room downstairs, so need to research what stuff i'll need to put down for that.

 

[oldbutnotdead]

That's a fair old shift you've put in there. Floor wise if you want to keep floor level where it was (which would be sensible) you look a bit short on depth for suspended timber which is a shame, yes its more time consuming than chucking concrete in but it is easier for running services around. Looking at the walls you're probably about as low as you want to dig in that clay so solid may be your best way forward, if you're serious about UFH then start looking at it now (before you do anything more about the floor).

 

[ianleon]

After much thought I am going to install UFH, its highly likely the rest of the house will need all the floors doing so it makes sense.

Just trying to work out what I can get done before I get the professionals.

Could someone advise me on what my next steps would be, as I understand I'm going to need a concrete slab, celetex and then screed.

Do I need to put some hardcore down first ?
What height should my concrete be ?
Is there a min and max for hight of the screed ?
At what level do I put my DPM in and to what height ?
Is there anything that go between the DPM and the new levels of surfaces ?

Thanks in advance for any help/advice.

 

[Deleted member 174758]

The sequence, bottom to top is something like:

HYard core (compacted)

Sand blinding (compacted - needed to ensure that you don't pierce the DPM with the hard core)

DPM (1000 or 1200g polythene aka Visqueen)

Cellotex or similar insulation

Dry mix screed (fills in around insulation - there will be gaps)

UFH

Second build of screed (in commercials this is 50 to 70mm, don't know about domestic, though)

SLC

Finish flooring including any underlay, etc.

 

[ianleon]

Thanks for the reply.

I have about 300mm to fill give or take 50mm in areas !
The flooring the boss wants down will be around 20mm
What sort of rough depths am I best to do the above to ?

 

[oldbutnotdead]

Have a look at UFH systems, select the one that will do the job, is affordable and will work with whatever your ultimate floor surface will be.
Then look at their specs for thickness of screed above/below and see how much depth you've got to play with once you've added 20mm for your floor plus any depth for fixings
You must get at least 100mm of insulation in and a DPM. If that clay is as firm as it looks you could probably skip hardcore so go sand, dpm, insulation, concrete, ufh, screed.
Usual thicknesses (in the Approved Docs, well worth a read) are hardcore 100mm, sand 50mm, insulation at least 100mm.

You may/may not be aware but this is notifiable work (renewing thermal elements, structure), if you're planning on DIYing it (and the rest of the floors) then download, read and comprehend the approved docs then put a Building Notice in. Building Control are not there to tell you how to do the job, they are there to ensure its done right. BUT if you do your homework & go to them with your scheme (along the lines of 'here's what the ADs suggest but I don't have the depth. Can I do this instead') then you may get lucky