Minimum Thickness Of Insulation

[adammid]

Any plumbers out there that can provide a bit of info. Have 22mm plastic pipe serving a garage. The garage is timber frame and insulated with insulated plaster board. The pipe will be run in a cavity approx 47mm in depth. What is the min size of insulation required? many thanks

 

[binky]

Cold water? think the minimumyou can get is about 10mm thick, but if going down that route, thicker the better.

 

[ProDave]

What sort of pipe?

mdpe will pretty much stand freezing without damage. Other types of "plastic" pipe may split if frozen.

Is your goal just to prevent damage, or to have a working tap all year?

If so you want the pipe INSIDE the insulated envelope of the building, even then some insulation would be advisable.

By the way I don't regard "insulated plasterboard" as being much in the way of insulation. That's just a thin backing of insulation behind the plasterboard sheet. As a minimum fill the whole 47mm cavity with kingspan or Celotex, then your insulated plasterboard.  Then fit as much insulation on the pipe as you can fit or afford.

 

[binky]

sounds like a plan to me PD, based on living in the frozen North :^O

 

[OnOff]

I think this subject comes under Byelaw 49. For copper but might assist:

http://www.ukcopperboard.co.uk/literature/pdfs/Installation-Tips/Insulation-and-Bylaw-requirements.pdf

 

[adammid]

It MDPE pipe. Its for a garden studio/ garage that someone will be living in so requires running water year round.

 

[ProDave]

If it's habitable accommodation, it will require planning permission and building regulations, so your insulation requirements will be dictated by that. :coat

(unless you are in Slough where such things seem to happen in every garden)

 

[Technician]

Insulation Matters: Water in an exposed situation ... - Groundbreaker

Just had a look at this;

In their view the best answer is an insulated duct, closed

at each end for a length of 38mm minimum, which gives

0.025 W/mK insulation at 0deg Cel.

It can give freezing protection for 48 hours at -13 deg Cel.

The problem is static water in the pipework for long periods

if the building is not continuously occupied.

HTH.