laying norfolk pamments.

[robgil]

i need a breathable floor in my kitchen guys , i have decided on norfolk pamments.
now , what are my options?
we are not sure if we will be using underfloor heating so we need a plan for both , so , what are my options?
the area is around 11 square meters and is presently concrete/latex and sopping wet.

so , do i use limecrete? sharp sand? anyone?

 

[Schoolmarm]

You need Jaqy, DWB, on here. She dug up all her floors and put LECA and limecrete down. You can have UFH after laying all that.

There are loads of pics and details somewhere.

 

[robgil]

thanks sm , i shall have a wee search and see what i can dig up.

 

[Schoolmarm]

She might need to link you to her photobucket account.

 

[MdB]

http://www.limecrete.org.uk/ has some useful info in it. Only done a very small area of limecrete myself so can't comment too much on that. I have installed my own underfloor system (on concrete I am afraid) though so can answer some questions on that if you have some.

 

[inwood]

I've done the same, limecrete floors throughout and relaid a mix of quarry tiles and the original pamments back down (although no UFH).

If you're thinking of installing underfloor heating you'll need to dig out a lot of material. Depending on the limecrete specs to meet current building regs for insulation it would be something like this:
Insulation 150mm
Limecrete slab 100mm
Screed with underfloor heating pipes 75mm
Screed to bed pamments into 20-35mm
Pamments 25mm

By my reckoning you'll be taking out up to 385mm depth. That's a hell of a lot of digging and possibility of undermining the foundations if you're not careful. Unfortunately it's the screed needed for the UFH pipework that's your killer. It also needs to be left to fully cure and dry before you can test and run it. It will also need to be left swtiched off until your bedding screed and pamments are installed, cured, dried and sealed (Osmo Polyx is excellent for 'sealing' pamments and remains breathable).

I just bedded the pamments into a wet screed of about 30mm onto the limecrete slab. Some have subsequently loosened and need relaying but probably only about 5%. It tried to get very thin grout lines and partially failed - although they do look good. If you want thin grout lines look up grouting using a lime slurry and sawdust (used to removed the slurry once grouted). It's apparently the best way to do it - I'd love to give it a go but only found out that was the way it was originally done after I'd laid mine.

 

[robgil]

thanks guys , looks like ive got a lot of digging to do. do building regs for new floors differ from property to property? the kitchen where i am laying the new floor is clay lump with little , if any foundations and i dont want to dig down too far if it might damage the building.

 

[Moo]

Or you could do what we (or, rather, our builders) did. They simply put the pamments back on the original hard-packed earth.
A dozen years on they're doing fine - no subsidence, no damp, no overdraft.

 

[robgil]

i have thought about just laying the pamments on whatever is under the cement floor but wouldn't Mr Buildings Inspector wag his finger at me for doing so?
basically i want to stay within current building regs without excavating away half of suffolk.
to replace a cement floor i do need to get a buildings inspector out to sign it off , dont i?

 

[Penners]

Or you could do what we (or, rather, our builders) did. They simply put the pamments back on the original hard-packed earth.
A dozen years on they're doing fine - no subsidence, no damp, no overdraft.

And presumably no underdraught either.

 

[AMc]

i have thought about just laying the pamments on whatever is under the cement floor but wouldn't Mr Buildings Inspector wag his finger at me for doing so?

Yes and with good reason, underfloor heating with no insulation is going to waste massive amounts of energy. If you don't get approval and meet the regs then you risk problems selling your house in future.

I'd broadly concur with inwood's floor construction though it's a bit deeper than we've had approved in order we had...
35mm pamments 'grouted' brushed mix of kiln dried sand and lime (7:1)
20mm lime/sharp sand bed
65mm concrete screed around the underfloor heating pipe*
100mm of isotherm insulation
25mm sharp sand
100mm of concrete over site*
150mm compacted hardcore

The approval was for 90mm insulation but 100mm was all I could get at the time I needed it. You could probably use a bit less and still meet the minimum standard.

It was a lot of digging, but once your down there and filling skips a few more mm isn't that big a deal PROVIDING you have deep enough footings to begin with. A test pit or three to have a look will be required before you start!

*My floor isn't breathable because there is no point in putting a breathable floor into walls and roof that aren't and there was no way to make the rooms work with the required amounts of breathable insulation.