ThermaWrap Spiral Pipe Wrap -- how does it compare with foam insulation?

Ed_Jogg

Has anyone used ThermaWrap Spiral Pipe Wrap for insulating cold/hot water pipes?

It is a strip of foil-coated bubble-wrap which you wind round and round a pipe in a long spiral (hence the name), as an alternative to the split foam tubes that just slip over the pipes.

In our loft I want to improve the insulation on about 20m of piping -- mostly central heating pipes to the radiator in the loft conversion -- which is currently covered in a sort of loose sacking material.

The Thermawrap stuff should work out at about half the cost of the thick-walled split foam tubing, and is supposed to be the equivalent of 30mm of polystyrene (and therefore better rated than the split foam?)

I can't decide which installation is likely to take longer. The CH pipes run as a pair for much of their length, but spaced too wide to allow both to be covered in one strip of Thermawrap, so I'll have to keep feeding the insulation betwen the pipes. On the other hand, the foam tubes need mitring at bends and joints, and to be fully effective, really need cut-outs made for the many pipe clips.

Also, should I remove the 'sacking' before applying the ThermaWrap, or will they work effectively in combination, with the foil over the top?

Any reviews or advice gratefully received?

27col

If you have time to waste then the spiral wrap is the way to waste it. Split insulation has to be much easier to fit. It is the work of minutes to notch round clips and a darn site easier to remove if you ever have to. I would think that the spiral wrap would take at least as long to fit as the old sacking type . I know from experience that fitting that is pretty tedious.

Ed_Jogg

Thank you for your thoughts. I've used the foam stuff before.The extra time is only going to be worthwhile if the insulating properties are substantially better; however, there is a cost difference too, which cannot be ignored, since I need to cover about 20m of pipe.

The 'sacking' type used here is actually a tube form that was threaded on when the plumbers installed the pipes (as far as I can make out) -- it's certainly not a spiral fit, although I'm sure I've seen that (unravelling) in older properties. This stuff looks rather thin, so I don't know how effective it is, except that none of the pipes have frozen thus far!

Unhelpfully, Thermawrap specify their stuff with a thermal resistance of 0.79M2K/W, whereas the B&Q site gives thermal conductivity of 0.034 W/mK for 13mm thick insulation (52p/m) and for 25mm thick, doesn't specify a rating (bl**dy helpful, eh?) (£1.80/m, "Compliant with Part L (April 2006) Building Regulations").

More research needed...

Ed_Jogg

Thought this deserved a separate post. A search for Climaflex, the most readily available brand, produced a comprehensive technical information sheet on the manufacturer's website:
Climaflex product literature.pdf

This explains what the regulations mean, and what thickness insulation you need to meet them...

Water Regulation W35 would seem to cover protection against freezing, and for 15mm pipe you'd need to use 25mm insulation for 'normal' conditions (that's inside the house) or 32mm for 'extreme' conditions (that's above the loft insulation, for example).

Building Regulation Part L covers heat loss from heating pipes. Here, 19mm thickness is adequate for 15mm pipes.

The PDF covers pipes ranging from 8mm to 76mm diameter!


So, going back to my earlier questions, it would seem that anything less than 25mm thick (equivalent) isn't worth considering. For 20m that's about £40 for foam, against £15 for the Thermawrap. But does the extra £25 for foam outweigh the 'cost' of the increased installation time of a spiral type...?

brig001

0.79M2K/W is the R value, 0.034 W/mK is the K value. R = thickness / K, so B&Q foam R value is 0.013 / 0.034 = 0.38

I think that is right anyway. Personally, I covered my pipes in foam, then wrapped the bubblewrap stuff round that, but I bought a wide roll from Wickes http://www.wickes.co.uk/Thermal-Insulation-Foil-Roll/invt/210022 used some for behind the radiators, then cut the rest into strips to wrap round the pipes.
HTH,
Bri.

Ed_Jogg

Hmm. Interesting.

So the 25mm stuff will have an R value of 0.025 / 0.034 = 0.74

And what I could do is fit the thin foam insulation, which is stupidly cheap by comparison, and cover that with foil as you did, to save time...

Ed_Jogg

The 'sacking' is actually (hair-) felt pipe insulation, such as this sold by Wickes. Looks very economical...except that there is no thermal rating given. I suspect it's not very good.

I found this thread 'elsewhere' that cast doubt about its effectiveness, and also questioned its fire safety (so I'll certainly be removing it when I put the other stuff on).

sheerdelight

I have just spent an hour accessing heatingpipes to cover them with insulation. Some pillock of a plumberyears ago left them unisulated under the floorboards. I had a roll or two of Supawrap spiral pipe insuation. Spent ages putting it on. Alas little room for anything due to thickness of cuts in joists. Anyway switched boiler on and pipes heated up quickly. Alas so did the outer surface of the insulation. I think this stuff is abysmal. Cost of it is irrelevant. Am toying with idea of putting foam insulation on albeit not the optimum thickness. I have some foam stuff elsewhere on same pipes and it keeps heat back much better than the pipe wrap. Spiral wrap says it is equivalent to 30mm of polystyrene.- must be non expanded polystyrene.