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Do ceiling batts deteriorate over time?

Filed under Ceiling Insulation, Insulation.

May 12th, 2009

Is there a life expectancy of Pink Batts? I have an ceiling that was batted I’d say at least 20 years ago and they are looking flat and thin. should they be replaced?


  • Tasman Insulation - manufacturers of Pink Batts, May 13th, 2009 on 9:06 pm

    Hi there…

    Pink Batts meets the requirements of NZBC B2.3.1a) 50 years. In the past the insulation requirements were lower than they are now, so the product looks much thinner than todays products. It will still be performing, so don’t throw it out, simply install another layer of Pink Batts over the top of your existing insulation.

    Thanks Alison Roberts
    Tasman Insulation

  • glen, January 31st, 2010 on 7:24 am

    How thick (mm) are the 2.9 rated pink batts?

  • editor, February 10th, 2010 on 10:52 pm

    Hi there, According to the product guide on the Pink Batts website the nominal stabilised thickness is:

    Ceiling batts R 2.6 = 140 mm, R 3.2 = 170 mm
    Wall Batts R 2.8 = 90 mm

    Note The wall batts have to be thinner (and more rigid) for a given R value so that they will fit in the wall cavity. This is achieved by adding plastic fibres to the batts, and is also a reason why wall batts cost so much more than ceiling batts .

    Sarah Free, energy advisor Wellington region

  • mike, December 12th, 2010 on 10:36 pm

    Although Fibre glass batts have the 50 year rating, the glues that hold them togther are constantly breaking down and if the batts are squashed from trades people or storage they will not bounce back and work at the original claimed performance.

  • Don, May 13th, 2012 on 12:08 pm

    Old Pink Batts definately thin over time, and slump, in which case wont perform like when they were first installed. Polyester performs better in regards to shrinkage and has much better resilience.

  • Mrs Wendy McNaughton, July 9th, 2012 on 8:03 pm

    Can you please tell me how long pink batts last in a ceiling, my parents in Oamaru put pink batts in 9 years ago, and have been told today that they need to top them up. We find this hard to
    believe. Thanks

  • melinda hawkes, May 8th, 2013 on 2:10 pm

    We are putting insulation in our 125 year old house, only to find that the extension on the back of the house ( probably done in the 70s) already had fibreglass insulation in the skillion ceiling.should we leave it there or would we be best to replace it with a more efficient polyester batt. There is not really room to put new batts on the top of old.

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