One of the most forgotten details regarding air tightness

We all want to achieve the best values for air tightness for our homes.

Good air tightness is not subjected to the brand of air tight products you use, but definitely how good and accurate they have been installed. It´s as always - the devil is in the detail.


One of the most forgotten or bad treated detail regarding air tightness can be found in every socket. As far as I know, the conduits here in Ireland have to be used to protect the wires against aggressive substances coming out of the blockwork. Unfortunately every conduit creates a small draught which is comparable to a chimney.  The photo underneath shows the amount of air infiltration during an air tight pre-test @50pa pressure difference.


The value of 0.35m/s was measured in almost every socket in the house. This means, every socket is creating an air Infiltration of 1.26 liter per hour in case the conduits will not be sealed with an approriate sealant. We wouldn´t recommend the use of expanding foam, as seen during another test a few months ago.

The most expanding foams here in Ireland are not good enough regarding fire protection. And the air tightness will get definitely weak, as soon as the electrician has to remove the most of the foam to get the 2nd fix of his installation done.


We´ll probably have a suitable sealant solution in stock soon, which creates an air tight sealing without destroying the fire behaviour.




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Comments: 6
  • #1

    Brendan (Sunday, 18 February 2018 17:39)

    Did you manage to source a sealant solution for this ?

  • #2

    prodomo Ireland (Sunday, 18 February 2018 17:46)

    Yes, of course. But to have this detail completely draught free, you need to apply an air tight coat to the chasing before installing the conduit. Sealing the conduit itself is not that difficult, but I highly recommend a fire-rated sealant.

  • #3

    Mick Heffernan (Friday, 16 October 2020 22:53)

    Is sealing chases required on all chases or just those on the walls exposed to outside

  • #4

    prodomo Ireland (Saturday, 17 October 2020 00:31)

    Hi Mick, usually you just need to seal the chases on exterior walls. Some building designs have cavity walls extending to the inside of the building. In this case, chases on such walls have to be sealed as well.

  • #5

    James (Tuesday, 08 December 2020 12:39)

    Any photos of the sealant at the top of the electrical conduit as it enters the in the attic space?
    Is Orcon F Sealant suitable for this

  • #6

    prodomo Ireland (Tuesday, 08 December 2020 12:49)

    My aplologies but I´m not in the position to give you advises about competitors products.