MDPE Pipe Insulation Thickness Query

[tododo]

Hi all

Ive laid and insulated new mdpe pipe under my floorboards and now just about to core drill near the inside cavity wall and then put in 100mm ducting in and then place the mdpe in that

As I understand it as we are going out nearer than 750mm to the external wall the mdpe pipe will need to be insulated where is comes up from the outside

I gather this armaflex is the stuff to go for - is that correct???? How thick?? ive seen the 28mm internal diameter stuff with a 25mm or 32mm wall thickness - so Im thinking of getting the 32mm thick stuff for the ducting to the outside

However the other query I have is the MDPE pipe under the timber floor - Ive gone and put the grey pipe insulation on from screwfix at the mo which is 13mm thick - should this be a thicker lagging

I cant seem to find any ideal thickness or specifications anywhere

Thanks for any advice - may as well do it right now

 

[cdbe]

When I did mine it was quite thin walled (I can't remember what it was - from eBay - but it was a continuous length about 6m). I am a bit confused about your ducting/insulation plan. When I did mine, through wall at front of house at 750mm and under suspended floor to kitchen I had to insulate and duct the whole 6m run until it came out in the kitchen (I used 110mm soil pipe) and cap off each end (it's to stop vermin eating it).

 

[tododo]

I dont think you have to duct when its under a suspended wooden floor but you never know - I dont think its clear when Ive looked again here:

https://www.southernwater.co.uk/Media/Default/PDFs/WaterSupplyRegs.pdf

I know it has to go in a duct when your going under the foundations of the house and to the outside but not sure on the ducting when its on a run under the wooden floor??

Getting more and more of a pain this job is and I havent even gone to the outside yet

Ive only been concerned with the thickness of the insulation up too this point - but ducting does make sense I suppose

 

[Mike2007]

You probably have to put in armour and six inch of insulation these days. The country has gone mad.

 

[cdbe]

Those diagrams are a bit ambiguous. My area was united utilities but their guidance sheet seem to have been take offline. I would call your provider and check. The other things that my inspector seemed to like were sand in the bottom of the trench and a proper temporary stop end on "his" end of the pipe rather than that little plastic cap that comes with the coil of pipe. And if you're capping off the old pipe it's good to have this exposed and show him what you're capping it with - usual a philmac or similar.