Vapour barrier - Revision history

Designing Buildings at 07:14, 5 February 2025

2025-02-05T07:14:59Z

← Older revision		Revision as of 07:14, 5 February 2025
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	Some types of rigid foam insulation have a foil bonded to their surface which will act as a vapour barrier, however, care must still be taken to ensure that joints and edges are properly sealed.		Some types of rigid foam insulation have a foil bonded to their surface which will act as a vapour barrier, however, care must still be taken to ensure that joints and edges are properly sealed.

−	= Related articles on Designing Buildings ~~Wiki~~ =	+	NB Approved document C: Site preparation and resistance to contaminants and moisture, 2004 edition incorporating 2010 and 2013 amendments defines a vapour control layer as: ‘Material of construction, usually a membrane, that substantially reduces the water vapour transfer through any building in which it is incorporated.’
		+
		+	= Related articles on Designing Buildings =

	* Barrier wall system.		* Barrier wall system.

Editor: Reverted edits by 102.118.22.216 (talk) to last revision by Designing Buildings

2021-11-05T10:12:09Z

Reverted edits by 102.118.22.216 (talk) to last revision by Designing Buildings

← Older revision		Revision as of 10:12, 5 November 2021
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−	As warm, moist internal air permeates through the external envelope of a building towards the outside, it will tend to cool. it reaches its ‘dew point’ temperature, the moisture it holds will begin to condense as water. If this happens within the structure of the building itself, this is known as interstitial condensation.	+	As warm, moist internal air permeates through the external envelope of a building towards the outside, it will tend to cool. When it reaches its ‘dew point’ temperature, the moisture it holds will begin to condense as water. If this happens within the structure of the building itself, this is known as interstitial condensation.

	If interstitial condensation occurs within the inner skin of the building envelope, it can cause problems such as:		If interstitial condensation occurs within the inner skin of the building envelope, it can cause problems such as:

102.118.22.216 at 10:10, 5 November 2021

2021-11-05T10:10:34Z

← Older revision		Revision as of 10:10, 5 November 2021
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−	As warm, moist internal air permeates through the external envelope of a building towards the outside, it will tend to cool. ~~When~~ it reaches its ‘dew point’ temperature, the moisture it holds will begin to condense as water. If this happens within the structure of the building itself, this is known as interstitial condensation.	+	As warm, moist internal air permeates through the external envelope of a building towards the outside, it will tend to cool. it reaches its ‘dew point’ temperature, the moisture it holds will begin to condense as water. If this happens within the structure of the building itself, this is known as interstitial condensation.

	If interstitial condensation occurs within the inner skin of the building envelope, it can cause problems such as:		If interstitial condensation occurs within the inner skin of the building envelope, it can cause problems such as:

Designing Buildings at 08:28, 21 September 2020

2020-09-21T08:28:52Z

← Older revision		Revision as of 08:28, 21 September 2020
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	* Vapour permeability.		* Vapour permeability.

−	[[Category:~~Products_/_components~~]] [[Category:DCN_Product_Knowledge]]	+	[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:DCN_Product_Knowledge]] [[Category:Products_/_components]]

185.47.105.44 at 14:30, 3 October 2019

2019-10-03T14:30:21Z

← Older revision		Revision as of 14:30, 3 October 2019
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	Care must be taken to ensure that vapour barriers are installed properly, so that they are continuous, and that joints, edges, junctions, cuts and penetrations are sealed. Particular care must be taken around openings such as ceiling hatches, and service penetrations such as cables, ducts, sockets, light fittings, and so on.		Care must be taken to ensure that vapour barriers are installed properly, so that they are continuous, and that joints, edges, junctions, cuts and penetrations are sealed. Particular care must be taken around openings such as ceiling hatches, and service penetrations such as cables, ducts, sockets, light fittings, and so on.

−	As well as preventing interstitial condensation, vapour barriers can ~~improving~~ the airtightness of the buildings. However, typically vapour barriers have a very low permeability, but are not completely airtight. Where they are airtight, they may be described as air and vapour control layers (AVCLs). Preventing the passage of air through the structure, can improve its thermal performance. In addition, some vapour barriers may include a low-e (low emissivity) metalised foil in their construction to improve thermal efficiency.	+	As well as preventing interstitial condensation, vapour barriers can improve the airtightness of the buildings. However, typically vapour barriers have a very low permeability, but are not completely airtight. Where they are airtight, they may be described as air and vapour control layers (AVCLs). Preventing the passage of air through the structure, can improve its thermal performance. In addition, some vapour barriers may include a low-e (low emissivity) metalised foil in their construction to improve thermal efficiency.

	Vapour barriers may include an adhesive face, or adhesive laps and may have some ‘elastomric’ properties, giving a limited self-sealing capability if penetrated.		Vapour barriers may include an adhesive face, or adhesive laps and may have some ‘elastomric’ properties, giving a limited self-sealing capability if penetrated.
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	* Vapour permeability.		* Vapour permeability.

−	[[Category:Products_/_components]]	+	[[Category:Products_/_components]] [[Category:DCN_Product_Knowledge]]

Designing Buildings at 07:08, 24 May 2019

2019-05-24T07:08:34Z

← Older revision		Revision as of 07:08, 24 May 2019
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	* Damp proof course.		* Damp proof course.
	* Damp.		* Damp.
−	* Defects in brickwork.
−	* Defects in stonework.
	* Dew point.		* Dew point.
−	* Emissivity.
	* Flashing.		* Flashing.
−	* Floor insulation.
−	* Heat loss.
	* Humidity.		* Humidity.
−	* Insulation.
	* Interstitial condensation.		* Interstitial condensation.
	* Penetrating damp.		* Penetrating damp.
	* Rising damp.		* Rising damp.
−	* ~~Roof insulation.~~	+	* Vapour permeability.
−	* Sarking.	+

	[[Category:Products_/_components]]		[[Category:Products_/_components]]

Editor at 15:15, 21 November 2018

2018-11-21T15:15:51Z

← Older revision		Revision as of 15:15, 21 November 2018
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	Some types of rigid foam insulation have a foil bonded to their surface which will act as a vapour barrier, however, care must still be taken to ensure that joints and edges are properly sealed.		Some types of rigid foam insulation have a foil bonded to their surface which will act as a vapour barrier, however, care must still be taken to ensure that joints and edges are properly sealed.

−	~~= Find out more =~~	+	= Related articles on Designing Buildings Wiki =
−		+
−	=== Related articles on Designing Buildings Wiki ===	+

	* Barrier wall system.		* Barrier wall system.
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	* Flashing.		* Flashing.
	* Floor insulation.		* Floor insulation.
		+	* Heat loss.
	* Humidity.		* Humidity.
	* Insulation.		* Insulation.

Editor at 16:18, 19 April 2018

2018-04-19T16:18:15Z

← Older revision		Revision as of 16:18, 19 April 2018
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	Vapour barriers might also be used in timber frame constructions, roof and floor constructions as well as in high humidity buildings such as swimming pools and factories.		Vapour barriers might also be used in timber frame constructions, roof and floor constructions as well as in high humidity buildings such as swimming pools and factories.

−	Care must be taken to ensure that vapour barriers are installed properly, so that they are continuous, and that joints, edges, junctions, cuts and penetrations are sealed. Particular care must be taken around openings such as ceiling hatches, and service penetrations such as cables, ducts, sockets, light fittings and so on.	+	Care must be taken to ensure that vapour barriers are installed properly, so that they are continuous, and that joints, edges, junctions, cuts and penetrations are sealed. Particular care must be taken around openings such as ceiling hatches, and service penetrations such as cables, ducts, sockets, light fittings, and so on.

	As well as preventing interstitial condensation, vapour barriers can improving the airtightness of the buildings. However, typically vapour barriers have a very low permeability, but are not completely airtight. Where they are airtight, they may be described as air and vapour control layers (AVCLs). Preventing the passage of air through the structure, can improve its thermal performance. In addition, some vapour barriers may include a low-e (low emissivity) metalised foil in their construction to improve thermal efficiency.		As well as preventing interstitial condensation, vapour barriers can improving the airtightness of the buildings. However, typically vapour barriers have a very low permeability, but are not completely airtight. Where they are airtight, they may be described as air and vapour control layers (AVCLs). Preventing the passage of air through the structure, can improve its thermal performance. In addition, some vapour barriers may include a low-e (low emissivity) metalised foil in their construction to improve thermal efficiency.
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	* Rising damp.		* Rising damp.
	* Roof insulation.		* Roof insulation.
		+	* Sarking.

	[[Category:Products_/_components]]		[[Category:Products_/_components]]

Editor at 14:55, 6 December 2017

2017-12-06T14:55:45Z

← Older revision		Revision as of 14:55, 6 December 2017
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	* Cavity wall insulation.		* Cavity wall insulation.
	* Cavity wall.		* Cavity wall.
		+	* Chemical injected DPC.
	* Cold bridge.		* Cold bridge.
	* Damp proof course.		* Damp proof course.

Editor at 16:46, 16 November 2017

2017-11-16T16:46:00Z

← Older revision		Revision as of 16:46, 16 November 2017
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−	As warm, moist internal air permeates through the external envelope of a building towards the outside, it will tend to cool. When it reaches its ‘dew point’ temperature, the moisture it holds will begin to condense as water. If this happens within the structure of the building itself, this is known as interstitial condensation. If interstitial condensation occurs within the inner skin of the building envelope, it can cause problems such as:	+	As warm, moist internal air permeates through the external envelope of a building towards the outside, it will tend to cool. When it reaches its ‘dew point’ temperature, the moisture it holds will begin to condense as water. If this happens within the structure of the building itself, this is known as interstitial condensation.
		+
		+	If interstitial condensation occurs within the inner skin of the building envelope, it can cause problems such as:

	* Mould growth, migration of salts, mildew and staining.		* Mould growth, migration of salts, mildew and staining.
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	=== Related articles on Designing Buildings Wiki ===		=== Related articles on Designing Buildings Wiki ===

		+	* Barrier wall system.
	* Breathable membranes market.		* Breathable membranes market.
	* Breather membrane.		* Breather membrane.