What do you think of this for internal insulation spec

[3CC]

In spite of some very strong opposition from a minority that I have spoken to, we have decided to go for internal insulation on our 1970's hollow block house. External insulation is just not practical albeit that it is a good technical solution.

The risk of of internal insulation as far as I can glean is interstitial condensation leading to mold.

So we have decided to mount the insulation on vertical battens which will allow an airflow up/down in the cavity between the insulation and the wall. At the top this cavity will be open to the attic and at the bottom it will be open to the void below the suspended floor. The airflow across the attic should cause a stack effect which will draw air up through the cavity.

In addition to this, great care will be taken to ensure the integrity of vapour barrier on the inner (warm) face of the insulation.

I intend to provide an intumescent strip horizontally at the intermediate floor level to address any risk of fire spread behind the insulation.

As far as I can see, this addresses the only real risk associated with internal insulation. Any comments?

 

[Lak]

I have yet to hear any negative feedback from any dry lining I have done over many years, dot and dab or direct fixing to walls, indeed would be interested to hear of any one that has had a problem arise from insulating this way, theoretically it could be problematic but in reality I have never experienced any thing other than delight after dry lining a house.

 

[Simeon]

As legs has said, theory and practice differ. With almost 40 years experience in plastering/dry-lining/insulation, I have yet to see a problem with this type of insulation. I'd imagine that any organisms need oxygen to thrive. Insulation boards mushroomed to the wall, taped and plastered make the wall airtight ........ go figure. Insulation fixed on battens may not be as good insulation wise .......... but in taking down old insulated walls have not seen any of the problems so loved by the theory experts. If you've got rising damp or lateral penetration that's another story.