More air-tightness

As I have already said, as well as high levels of thermal insulation, we are making the house as airtight as possible: so absolutely no drafts.

This has been a major undertaking – very slow and painstaking to make it satisfactory.  We are making the inside of the insulation our principal air-tight layer – to create an entire envelope around the house.

We have taken advice from an air-tightness specialist – and in fact we may have left this rather too late in the day.  His view was that we should build up many layers of air-tightness, as air has such an uncanny way of finding and creeping along any possible gaps and tracking from one area to another. Also, many layers probably provide a more robust solution for the longer term.  He would have started, for example, with sealing the brickwork on the inside –  we did this up to a point in places though not for this reason, and not comprehensively.  He also recommended taping both sides of the insulation joints – but it is hard to know whether this is overkill and where to stop.  We are never going to achieve perfect air-tightness in an old house.

He thought there were lots of good points in what we have done, including:

  • staggered joints in the inner and outer layers of insulation on the external walls,
  • good taping at the edges of each board
  • space between the floor and ceiling well taped around all the joists
  • air-tight membrane in window reveals, taped to window frames and walls.
Under the eaves at the very front of the house in the attic has been left as cold space and outwith the air-tight envelope.  Therefore, there has had to be a major layer of DB+ membrane around this, projecting into the ceiling of bedroom 1.

Under the eaves in the attic is being left as cold space, hence the  floor  behind the studwork,
 and eventually the studwork, will be insulated.

This is the area at the front of bedroom 1 that is under this cold space in the attic, so it too is insulated.

The wall insulation is then continued up to meet the ceiling insulation and everything well taped.

The continuity of air-tightness from above coming through the floor
from the attic above.

The whole area, including all over the joists, is encased in DB+ membrane and taped.

Residual gaps were filled with expanded foam.  Here the tops of the walls in the first floor ensuite
(where they are against the external wall) have foam squirted in.

1 Comment

dipak upadhyay

about 6 years ago

This insulation is covered with a protective mesh and tight delivery that is extremely durable and has a high impact resistance. Wall Insulation is a more expensive way to insulate the walls of your home, but it is highly effective


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