📨 Have you signed up to the Forum's new Email Digest yet? Get a selection of trending threads sent straight to your inbox daily, weekly or monthly!

Waterproof pipe lagging

Bought a house earlier this year and the last owner mentioned that the condensate pipe on the boiler occasionally freezes up in winter.

Being the proactive type that I am, I want to try and prevent this this coming winter. The boiler is downstairs, with the 21.5mm condensate pipe exiting the wall, then straight down at a 90 degree bend vertically into a drain. Just past the 90 degree bend, the existing 21.5mm pipe goes into a 32mm pipe, where british gas tried (halfheartedly) to solve the problem. Whilst it helped, he advised that it sometimes still freezes up. I'm guessing the 21.5mm 90 degre bend is the weak point.

I know the correct way is to re-route the pipe internally but I'd rather look at lagging the pipe outside. Does anyone know where to buy waterproof pipe lagging - not having much luck on plumb center website or anywhere else.

Comments

  • cajef
    cajef Posts: 6,283 Forumite
    Part of the Furniture 1,000 Posts Name Dropper Photogenic
    I used a water resistant foam pipe similar to this a couple of years ago, they also do a white one that is suitable for underground so would imagine that must be waterproof.

    http://www.insulationandlagging.co.uk/Pipe-Insulation/Class-0-Armaflex-Self-Seal-Pipe-Insulation-Lagging-Self-Adhesive


    http://www.insulationandlagging.co.uk/Pipe-Insulation/Underground-Pipe-Insulation
  • zzzLazyDaisy
    zzzLazyDaisy Posts: 12,497 Forumite
    Part of the Furniture Combo Breaker
    The 90 degree bend is the problem.

    My condensate pipe ran down the wall then a 90 degree bend to the drainage pipe. The last bit ran along the ground and didn't have much/any slope. In very cold weather, the water collected and froze around the joint and then backed up until it flooded the boiler.

    Lagging on its own didn't help, so I had the pipe re-routed so the joint was higher up the pipe and the second part ran diagonally down across the wall to the drainage pipe.

    This seems to have cured the problem although last winter was not as cold, so who knows.
    I'm a retired employment solicitor. Hopefully some of my comments might be useful, but they are only my opinion and not intended as legal advice.
  • keystone
    keystone Posts: 10,916 Forumite
    It should have been done in 32mm waste pipe in the first place rather than overflow pipe. Anyway your best solution would be to box it in and line the inside of the box with some insulation.

    Cheers
    The difference between genius and stupidity is that genius has it's limits. - Einstein
  • ROY47
    ROY47 Posts: 555 Forumite
    Part of the Furniture 500 Posts Combo Breaker Car Insurance Carver!
    I cut mine off at the 90 bend where I had the same freezing problem 2 years ago

    Mine now drains into a kiddies "sand castle bucket" and I empty the bucket into the drain when it's nearly full

    problem solved , it's never frozen up since
  • Horizon81
    Horizon81 Posts: 1,594 Forumite
    Part of the Furniture 1,000 Posts Combo Breaker
    Thanks for the replies. The run is almost completely vertical, obviously it exits the wall then hits a 90 degree bend and points downwards on a slight diagonal to the drain.

    I'll try and get some 25mm wall x 22mm bore armaflex for it.
    Cajef - how come the price on the website you mention is £5.96 for a 2 metre piece whereas its over £40 in plumbcenter for teh same length!?
  • T_T_2
    T_T_2 Posts: 880 Forumite
    Horizon81 wrote: »
    how come the price on the website you mention is £5.96 for a 2 metre piece whereas its over £40 in plumbcenter for teh same length!?

    Because the list price for Tubalit and Armaflex is notoriously high. Decent discount for trade customers can be anywhere from 65-85% off list. All plumbers' merchants will have what they call a 'trade cash backdrop account' This is cash account that they book goods to when a non-account holding customer comes in. It automatically applies the kind of terms you would expect to get as a one off trade customer rather than a retail customer. Next time ask them what the trade cash price is.
  • Horizon81
    Horizon81 Posts: 1,594 Forumite
    Part of the Furniture 1,000 Posts Combo Breaker
    So it doesn't matter if you're a non trade customer?

    Or what about a standard foam lagging, but coated with duct tape? That should waterproof it shouldn't it? We're not talking about a very long run so wouldn't take long.
  • T_T_2
    T_T_2 Posts: 880 Forumite
    edited 6 November 2012 at 1:41PM
    Horizon81 wrote: »
    So it doesn't matter if you're a non trade customer?

    Or what about a standard foam lagging, but coated with duct tape? That should waterproof it shouldn't it? We're not talking about a very long run so wouldn't take long.

    Waterproofing isn't the main problem, exposure to UV is the real problem. Foam lagging (I assume you mean tubolit/climaflex type of pipe insulation - the grey stuff) will start to deteriorate over time as it is exposed to the sun. I'm not sure how much this will be mitigated by duct tape. The Armaflex (black stuff, also known as donkey d*ck) is UV stablised and will not deteriorate in the sun.

    Edited to add: I should have specified that only Armaflex HT is UV stabilised. I've just been told that they also do a product called Armaflex HT S that is specifically made for use outside.
  • ListysDad
    ListysDad Posts: 312 Forumite
    Part of the Furniture 100 Posts Combo Breaker
    A bit of advice if I may as this is my specialism...

    Firstly, only nitrile based insulation is suitable for retrofitting for frost protection. The reason for this is because the polyethylene stuff (climaflex and its ilk) starts to physically shrink at 4 degrees centigrade not MINUS 4 but 4. In addition, one cannot glue polyethylene insulation effectively so you cannot make a vapour barrier.

    Secondly, freezing occurs when the heat in the water is lost. Obviously this occurs literally in a second with the small drips of condensate into the pipe. Oddly enough, despite the advice to increase discharge pipe size, that makes matters worse. Air currents, that circulate in a larger diameter pipe, cause faster cooling so I NEVER increase the condensate pipe size. If I have to run it outside, I set it off the wall and install 32mm wall armaflex. I also never run 90 deg bends but instead have 2 x 45's. Lastly, if it must be outside then run trace heating (again on the smaller pipe) and instead of 32mm insulation us just 13mm wall as any thicker can cause the trace heating to overheat and burn out.

    Regardless of the insulation, make sure it's installed properly. That means gluing all joints and fitting it under approx 10% compression to accommodate its shrinkage when it begins to get really cold.

    If I can help any further just ask.
    :whistle: All together now, "Always look on the bright side of life..." :whistle:
This discussion has been closed.
Meet your Ambassadors

🚀 Getting Started

Hi new member!

Our Getting Started Guide will help you get the most out of the Forum

Categories

  • All Categories
  • 350.4K Banking & Borrowing
  • 252.9K Reduce Debt & Boost Income
  • 453.3K Spending & Discounts
  • 243.4K Work, Benefits & Business
  • 598K Mortgages, Homes & Bills
  • 176.6K Life & Family
  • 256.4K Travel & Transport
  • 1.5M Hobbies & Leisure
  • 16.1K Discuss & Feedback
  • 37.6K Read-Only Boards

Is this how you want to be seen?

We see you are using a default avatar. It takes only a few seconds to pick a picture.