Hot water pipe insulation - application advice

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darrenw

5 posts

Wannabe Geek

#288731 19-Jul-2021 16:20

Wanting to insulate our hot water pipes which run underfloor (accessible) and are currently bare, apart from a short length that was installed with a new mains pressure HWC. It's a 1950s house with mix of galv and plastic pipework for hot water, ranging from 16-28mm OD, around 13m total length.

Bunnings have got a range of 13mm thickness elastomeric tube. The price is reasonable but I wonder if it's worth tracking down a thicker option?

Is a self-adhesive option worthwhile (I don't think the Bunnings stuff is)? Who best to supply in the small quantities I'll need? (I'm in Christchurch)

If it's not self-adhesive, is tape/cable tie around each end sufficient, or should the whole length be taped to eliminate any gaps?

Anyone have an opinion on the linear wool products from the likes of Terra Lana? The linear pipe wrapping is versatile but seems pretty inconvenient compared to just slipping on a formed tube...

Thanks for your thoughts/tips!

Kickinbac

427 posts

Ultimate Geek

#2747333 20-Jul-2021 20:43

Any insulation will help, most of the time you are just slowing the standing losses. 13mm elastomeric should be fine. If you can get 19mm do that. If you can get the self adhesive pre cut that will be easier to install otherwise you need to cut along the length then either glue it back together with contact adhesive or you can tape it with 50mm wide pvc duct tape, like wide insulation tape. Tape around it to hold it in place then along the join to hold it closed. No gaps. Don’t use cable ties as this crushes the insulation.
You can get insulation from plumbing merchants or try refrigeration wholesalers like Pattons, Real Cold or Actrol.

neb

11294 posts

Uber Geek

Trusted

Lifetime subscriber

#2747770 21-Jul-2021 16:25

Is a self-adhesive option worthwhile (I don't think the Bunnings stuff is)?

It's useful, but probably not sufficient, eventually it'll start losing its adhesiveness and start to peel off, so your best option is to use self-adhesive and then reinforce with tape. Problem is that the universal go-to duct tape doesn't adhere well to the foam insulation and will eventually start to peel off, your best bet is black PVC tape with some overlap, so PVC-on-PVC rather than PVC-on-foam.

gzt

17111 posts

Uber Geek

Lifetime subscriber

#2747816 21-Jul-2021 19:32

neb: eventually it'll start losing its adhesiveness and start to peel off,

I don't know the brand I bought. I'm fairly sure this does not happen. I seem to recall it ripped the insulation on attempted removal and not the self adhesive part.

darrenw

5 posts

Wannabe Geek

#2747909 21-Jul-2021 23:56

Great, thanks all. I found some reasonable self-adhesive tubing at Placemakers, much cheaper than the walk-in price at the plumbing supply store next door, so I've gone with that. Pity installing it isn't quite as easy as buying it!!