Energy Efficient Through-holes

The sole responsibility for the content of this publication lies with the authors. It does not necessarily reflect the opinion of the European Union. Neither the EASME nor the European Commission are responsible for any use that may be made of the information contained therein.

Repository: Aho Hanna, Korpi Minna (edit)REALISATION OF AIR PROOF STRUCTURES AND CONNECTIONS IN RESIDENTAL BUILDING Techical university of Tampere Research report 141, 100 p.

Through-holes

Badly sealed AC through-holes have caused decay and mould in boarding.

When there is a vacuum inside the building, the mould spores move along to indoor air.

1

2

2 1

3

1. Plastic board is installed above the vapour barrier using separate battens. The vapour barrier of the roof is installed up against it.

Holes for pipe through-holes can be made before or after the board installation. The hole should be cut 30 - 40 mm wider than the diameter of the pipe.

2. Cellular plastic insulation is foamed under the vapour barrier and between the battens. The holes are made as before.

3. The hole-through pipe is foamed tight to the board collars in 1-2 layers.

Pipe through-holes with plastic heat insulation

1

2

3

1

2

3

3

2

1

Sealing through-holes for pipes in the roof of a log building

1. The vapour barrier foil is taped to the through-hole for the pipe approx. 5 cm under the vapour barrier of the roof.

2. The foil is pressed or pleated loosely.

3. The vapour barrier foil is tightened to the other vapour barrier of the roof by battens or separate tightening battens.

1

23

2

3

1

1001. A sheet metal collar is

fastened to the brick flue. The gap between the flue and the collar is sealed with a fire resistant joint compound before tightening.

2. The vapour barrier foil of the roof and the sheet metal collar are overlapped and the connecting joint is pressed to the bearer.

In-situ masonry flue through-holein a timber roof

1

2

1

20

Through-hole for stainless steel insulated chimney pipe in a timber roof

1. The vapour-proofing of the roof is turned up at the edges of the battens.

2. The gap between the flue and the roof batten is filled with fire-resistant mineral wool.

3. The joint is sealed with fire-resistant elastic jointing compound.

Check out also the instructions from the flue manufacturer!

1

2

3

2

3

1

100

Of in-situ masonry flue in the roof of a log building

1. The vapour barrier foil of the roof is left long around the chimney flue and it is folded up loosely between the battens and the fire protection.

2. The sheet metal collar is fastened around the brick flue. Between the flue and the collar is non-flammable elastic jointing.

3. The end of the vapour barrier foil is overlapped between the sheet metal collar and the fire protection and the joint is taped.

4. The gap between fire protection and battens should allow the structure to settle.

4

1

2

3

Electrical installation and electrical through-holes

1. Installations are made usually between the battens. They should not go through waterproofing.

2. Cables that go through the vapour barrier foil or pipe sleeves are installed using through-hole flashing.

3. Through-holes in plastic thermal insulation can be sealed by foaming.

4. The gap between the cable and the pipe sleeve is sealed with elastic jointing compound.

1

2 3

4

Industrial through-holes!

• Industrial manufactured through-hole flashings save installation time and simplify the making of airtight structures.

• NB Read the instruction manual before installation.

Exercise:

Search the internet for pictures of ”vapour barrier” and ”through-hole flashing”.

Remember• Make sure that the connection between through-holes and vapour

barrier foils will stay unbroken even with movements of the frame.

• Favour industrial manufactured through-holes used with a vapour barrier.

• If taping is used in the connections, choose a vapour barrier tape that is fit for the purpose.

• Structures should stay airtight for decades.

• The principles of through-holes on a roof can be applied to through-holes on walls and floors.

• Interior walls of apartments and intermediate floors should also be made air proof, so air pressures in the apartments can be controlled.

The good practices and principles required for the energy efficient building have been included in the teaching material. The writers are not responsible for their suitability to individual building projects as such. The individual building projects have to be made according to the building design of the targets in question.