Improving airtightness

ATC110

Hello all,

Having had problems with heatloss since moving in to a new house six years ago, I recently used a blower door to identify air ingress, it showed up the following areas:

1) Ground floor skirting boards - where the finished floor has shrunk slightly & left a narrow gap
2)Around the window boards and window frames - where the frame meets the wall
3)First floor skirting boards - possibly poor pointing where the joists enter the wall and the fact that the concrete blocks in the first floor cavity are air permeable
4)There is also a significant problem with heat retention in a room above an integral garage. It has three external walls , an internal cavity party wall between it and the rest of the house, a 225mm thick floor with 200mm of insulation in it & a dormer roof
5) There appears to be heatloss through the corner pieces of a 2.4m x 1.2m bay window

The course of action recommended is as follows:

1)Seal gap between finished floor and wall around perimeter of house
2)As above with window boards & frames
3)Cut a track in the ground floor ceiling around the perimeter of the building and insulate the block wall between each joist and around the joists
4) Internally insulate the party wall - on both sides - as this is only partially filled with cavity insulation.
Internally insulate the ceiling.
Cut track in perimeter of garage ceiling below, fill the 25mm gap in the ceiling / floor cavity by bunching up insulation, hold it in place with pieces of rigid insulation board, then fill the remainder.
Also seal the block wall/joists as mentioned above.
5) Coat corner pieces in Aerogel or similar and cover with uPVC moulding.


I would appreciate any comments on the above-mentioned course of action.
This would be to improve the air tightness and hopefully negate the need for external or internal insulation and/or new windows.

I also have the following questions:

What type of sealant should be used for the finished floor gap & window boards/frames? Would ordinary caulk/ mastic be suitable?

What would be the best way to insulate between/around the joists? It was suggested to use spray foam and/or rigid insulation sheets cut to size but I'm concerned about off-gassing of these products Hello all,

Having had problems with heatloss since moving in to a new house six years ago, I recently used a blower door to identify air ingress, it showed up the following areas:

1) Ground floor skirting boards - where the finished floor has shrunk slightly & left a narrow gap
2)Around the window boards and window frames - where the frame meets the wall
3)First floor skirting boards - possibly poor pointing where the joists enter the wall and the fact that the concrete blocks in the first floor cavity are air permeable
4)There is also a significant problem with heat retention in a room above an integral garage. It has three external walls , an internal cavity party wall between it and the rest of the house, a 225mm thick floor with 200mm of insulation in it & a dormer roof
5) There appears to be heatloss through the corner pieces of a 2.4m x 1.2m bay window

The course of action recommended is as follows:

1)Seal gap between finished floor and wall around perimeter of house
2)As above with window boards & frames
3)Cut a track in the ground floor ceiling around the perimeter of the building and insulate the block wall between each joist and around the joists
4) Internally insulate the party wall - on both sides - as this is only partially filled with cavity insulation.
Internally insulate the ceiling.
Cut track in perimeter of garage ceiling below, fill the 25mm gap in the ceiling / floor cavity by bunching up insulation, hold it in place with pieces of rigid insulation board, then fill the remainder.
Also seal the block wall/joists as mentioned above.
5) Coat corner pieces in Aerogel or similar and cover with uPVC moulding.


I would appreciate any comments on the above-mentioned course of action.
This would be to improve the air tightness and hopefully negate the need for external or internal insulation and/or new windows.

I also have the following questions:

What type of sealant should be used for the finished floor gap & window boards/frames? Would ordinary caulk/ mastic be suitable?

What would be the best way to insulate between/around the joists? It was suggested to use spray foam and/or rigid insulation sheets cut to size but I'm concerned about off-gassing of these products and the likes of aerogel.

I came across this product online http://www.greensteps.co.uk/tmp/assets/1210866730018.pdf - Would it be suitable?
Also, is there a non-toxic spray foam available?