Treating brickwork with sealant or water repellent - Revision history

Editor at 16:00, 25 January 2021

2021-01-25T16:00:15Z

← Older revision		Revision as of 16:00, 25 January 2021
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	Traditionally, the external brick walls of buildings were generally constructed without a cavity between the inner and outer leaves, however, they were thick enough to prevent moisture penetrating from the outside to the inside under most normal circumstances.		Traditionally, the external brick walls of buildings were generally constructed without a cavity between the inner and outer leaves, however, they were thick enough to prevent moisture penetrating from the outside to the inside under most normal circumstances.

−	Since the early part of the 20th century, most external brick walls have included a cavity between the inner and outer leaves, meaning that any moisture that penetrates through the outer ~~leave~~ runs down the outer face of the cavity and is drained to the outside.	+	Since the early part of the 20th century, most external brick walls have included a cavity between the inner and outer leaves, meaning that any moisture that penetrates through the outer leaf runs down the outer face of the cavity and is drained to the outside.

	In both these cases, if moisture does penetrate from the outside to the inside, it is generally because there is a defect in the wall construction. It could be that the wall has cracked, or there is a fault in the pointing, or gaps within the mortar, or the coping at the top of the wall is defective, there is a problem with a drain or rainwater downpipe, or the cavity has been breached or poorly filled. There could also be problems with condensation or rising damp that might give the appearance of penetrating damp.		In both these cases, if moisture does penetrate from the outside to the inside, it is generally because there is a defect in the wall construction. It could be that the wall has cracked, or there is a fault in the pointing, or gaps within the mortar, or the coping at the top of the wall is defective, there is a problem with a drain or rainwater downpipe, or the cavity has been breached or poorly filled. There could also be problems with condensation or rising damp that might give the appearance of penetrating damp.

Designing Buildings at 09:50, 21 September 2020

2020-09-21T09:50:22Z

← Older revision		Revision as of 09:50, 21 September 2020
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	* Tanking.		* Tanking.

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

Designing Buildings at 07:48, 30 August 2020

2020-08-30T07:48:22Z

← Older revision		Revision as of 07:48, 30 August 2020
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	= Conclusion =		= Conclusion =

−	Brick walls are intended to ~~‘breath’~~. They are permeable to moisture and water vapour, and this allows them to dry out if moisture penetrates them from the inside or outside. Any action taken to prevent this can have unforeseen consequences and should not be undertaken without careful consideration. It is always best to try and identify defects and correct them, rather than leaving the defects and trying to cover them up. Applying a sealant, repellent or tanking will not correct the underlying problem.	+	Brick walls are intended to ‘breathe’. They are permeable to moisture and water vapour, and this allows them to dry out if moisture penetrates them from the inside or outside. Any action taken to prevent this can have unforeseen consequences and should not be undertaken without careful consideration. It is always best to try and identify defects and correct them, rather than leaving the defects and trying to cover them up. Applying a sealant, repellent or tanking will not correct the underlying problem.

	The [http://www.brick.org.uk/about-the-brick-development-association/ask-the-expert/ Brick Development Association] states, 'We believe the use of sealants and water repellent treatments on brickwork is totally unnecessary and take the view that properly specified and built work performs perfectly satisfactorily in resisting water penetration by wind driven rain, without their need. Brickwork inevitably gets wet in rainy weather and dries out later. This is the way it works and has done so for thousands of years.'		The [http://www.brick.org.uk/about-the-brick-development-association/ask-the-expert/ Brick Development Association] states, 'We believe the use of sealants and water repellent treatments on brickwork is totally unnecessary and take the view that properly specified and built work performs perfectly satisfactorily in resisting water penetration by wind driven rain, without their need. Brickwork inevitably gets wet in rainy weather and dries out later. This is the way it works and has done so for thousands of years.'
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	* Tanking.		* Tanking.

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

Editor at 17:40, 5 February 2019

2019-02-05T17:40:55Z

← Older revision		Revision as of 17:40, 5 February 2019
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	* Condensation.		* Condensation.
	* Defects in brickwork.		* Defects in brickwork.
		+	* Parapet.
	* Penetrating damp.		* Penetrating damp.
	* Rising damp.		* Rising damp.
Line 68:		Line 69:
	* Tanking.		* Tanking.

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

Editor at 13:47, 15 March 2018

2018-03-15T13:47:37Z

← Older revision		Revision as of 13:47, 15 March 2018
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	= Introduction =		= Introduction =

−	Traditionally, the external brick walls of buildings were generally constructed without a cavity between the inner and outer leaves, however they were thick enough to prevent moisture penetrating from the outside to the inside under most normal circumstances.	+	Traditionally, the external brick walls of buildings were generally constructed without a cavity between the inner and outer leaves, however, they were thick enough to prevent moisture penetrating from the outside to the inside under most normal circumstances.

	Since the early part of the 20th century, most external brick walls have included a cavity between the inner and outer leaves, meaning that any moisture that penetrates through the outer leave runs down the outer face of the cavity and is drained to the outside.		Since the early part of the 20th century, most external brick walls have included a cavity between the inner and outer leaves, meaning that any moisture that penetrates through the outer leave runs down the outer face of the cavity and is drained to the outside.
Line 24:		Line 24:
	= Non-breathable sealants =		= Non-breathable sealants =

−	Non-breathable sealants can be applied to the external face of a wall where they form a film making it impermeable to moisture. These sealants are typically manufactured from materials such as; acrylics, stearates, urethanes, silicone resins and so on. However, these sealants will generally also make the wall impermeable to air movement, meaning that any moisture that does get into the fabric of the wall (such as water vapour from the inside, or interstitial condensation) will not be able to evaporate to the outside. This can result in a wall that is sealed, but nonetheless damp, and at risk from mould growth, frost damage and so on.	+	Non-breathable sealants can be applied to the external face of a wall where they form a film making it impermeable to moisture. These sealants are typically manufactured from materials such as; acrylics, stearates, urethanes, silicone resins and so on. However, these sealants will generally also make the wall impermeable to air movement, meaning that any moisture that does get into the fabric of the wall (such as water vapour from the inside, or interstitial condensation) will not be able to evaporate to the outside. This can result in a wall that is sealed, but nonetheless damp, and at risk from mould growth, frost damage, and so on.

	Non-breathable sealants are not permanent treatments, and have to be reapplied.		Non-breathable sealants are not permanent treatments, and have to be reapplied.
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	= Water repellents =		= Water repellents =

−	Water repellents can also be applied to the external face of a wall. They then penetrate through the fabric of the wall, making it repel moisture. However, the wall remains permeable to air movement, and so water vapour is still able to pass through the wall, reducing the likelihood of a build up of damp from the inside. Water repellent treatments include materials such as; siloxanes, silanes, silicates, methyl siliconates and so on.	+	Water repellents can also be applied to the external face of a wall. They then penetrate through the fabric of the wall, making it repel moisture. However, the wall remains permeable to air movement, and so water vapour is still able to pass through the wall, reducing the likelihood of a build up of damp from the inside. Water repellent treatments include materials such as; siloxanes, silanes, silicates, methyl siliconates, and so on.

	As with sealants, they are not permanent treatments, and have to be reapplied. However, as they penetrate into the brickwork, they are less prone to damage, or UV degradation.		As with sealants, they are not permanent treatments, and have to be reapplied. However, as they penetrate into the brickwork, they are less prone to damage, or UV degradation.
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	Additionally, tanking the inside of the wall means it will not absorb moisture that accumulates inside the building and so the likelihood of internal surface condensation will increase.		Additionally, tanking the inside of the wall means it will not absorb moisture that accumulates inside the building and so the likelihood of internal surface condensation will increase.
		+
		+	For more information, see Tanking.

	= Conclusion =		= Conclusion =
Line 46:		Line 48:
	Brick walls are intended to ‘breath’. They are permeable to moisture and water vapour, and this allows them to dry out if moisture penetrates them from the inside or outside. Any action taken to prevent this can have unforeseen consequences and should not be undertaken without careful consideration. It is always best to try and identify defects and correct them, rather than leaving the defects and trying to cover them up. Applying a sealant, repellent or tanking will not correct the underlying problem.		Brick walls are intended to ‘breath’. They are permeable to moisture and water vapour, and this allows them to dry out if moisture penetrates them from the inside or outside. Any action taken to prevent this can have unforeseen consequences and should not be undertaken without careful consideration. It is always best to try and identify defects and correct them, rather than leaving the defects and trying to cover them up. Applying a sealant, repellent or tanking will not correct the underlying problem.

−	The [http://www.brick.org.uk/about-the-brick-development-association/ask-the-expert/ Brick Development Association] states, ~~“We~~ believe the use of sealants and water repellent treatments on brickwork is totally unnecessary and take the view that properly specified and built work performs perfectly satisfactorily in resisting water penetration by wind driven rain, without their need. Brickwork inevitably gets wet in rainy weather and dries out later. This is the way it works and has done so for thousands of years.”	+	The [http://www.brick.org.uk/about-the-brick-development-association/ask-the-expert/ Brick Development Association] states, 'We believe the use of sealants and water repellent treatments on brickwork is totally unnecessary and take the view that properly specified and built work performs perfectly satisfactorily in resisting water penetration by wind driven rain, without their need. Brickwork inevitably gets wet in rainy weather and dries out later. This is the way it works and has done so for thousands of years.'

−	The Brick Institute of America however, suggest that the use of water repellant treatments may be appropriate under certain circumstances, if properly considered and applied.	+	The Brick Institute of America, however, suggest that the use of water repellant treatments may be appropriate under certain circumstances, if properly considered and applied.

−	Whatever solution is adopted, it is likely that action will also be necessary to treat problems inside the building which have been caused by the damp, such as mould, rot, defective plaster and so on.	+	Whatever solution is adopted, it is likely that action will also be necessary to treat problems inside the building which have been caused by the damp, such as mould, rot, defective plaster, and so on.

	= Find out more =		= Find out more =
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	* Rising damp in walls - diagnosis and treatment (DG 245).		* Rising damp in walls - diagnosis and treatment (DG 245).
	* Sealant.		* Sealant.
		+	* Tanking.

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

Editor at 12:12, 3 July 2017

2017-07-03T12:12:24Z

← Older revision		Revision as of 12:12, 3 July 2017
Line 63:		Line 63:
	* Rising damp.		* Rising damp.
	* Rising damp in walls - diagnosis and treatment (DG 245).		* Rising damp in walls - diagnosis and treatment (DG 245).
		+	* Sealant.

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

Designing Buildings at 06:27, 1 May 2017

2017-05-01T06:27:20Z

← Older revision		Revision as of 06:27, 1 May 2017
Line 62:		Line 62:
	* Penetrating damp.		* Penetrating damp.
	* Rising damp.		* Rising damp.
		+	* Rising damp in walls - diagnosis and treatment (DG 245).

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

Designing Buildings at 09:54, 2 February 2017

2017-02-02T09:54:11Z

← Older revision		Revision as of 09:54, 2 February 2017
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−	[[File:~~Damp inside a building~~.jpg]]	+	[[File:Damp_inside_a_building.jpg\|link=File:Damp_inside_a_building.jpg]]

	= Introduction =		= Introduction =
Line 24:		Line 24:
	= Non-breathable sealants =		= Non-breathable sealants =

−	Non-breathable sealants can be applied to the external face of a wall where they form a film making it impermeable to moisture. These sealants are typically manufactured from materials such as; acrylics, stearates, urethanes, silicone resins and so on. However, these sealants will generally also make the wall impermeable to air movement, ~~and will mean~~ that any moisture that does get into the fabric of the wall (such as water vapour from the inside, or interstitial condensation) will not be able to evaporate to the outside. This can ~~leave~~ a wall that is sealed, but nonetheless damp, and at risk from mould growth, frost damage and so on.	+	Non-breathable sealants can be applied to the external face of a wall where they form a film making it impermeable to moisture. These sealants are typically manufactured from materials such as; acrylics, stearates, urethanes, silicone resins and so on. However, these sealants will generally also make the wall impermeable to air movement, meaning that any moisture that does get into the fabric of the wall (such as water vapour from the inside, or interstitial condensation) will not be able to evaporate to the outside. This can result in a wall that is sealed, but nonetheless damp, and at risk from mould growth, frost damage and so on.

	Non-breathable sealants are not permanent treatments, and have to be reapplied.		Non-breathable sealants are not permanent treatments, and have to be reapplied.
Line 44:		Line 44:
	= Conclusion =		= Conclusion =

−	Brick walls are intended to ‘breath’. They are permeable to moisture and water vapour, and this allows them to dry out if moisture penetrates them from the inside or outside. Any action taken to prevent this can have unforeseen consequences and should not be undertaken without careful consideration. It always best to try and identify defects and correct them, rather than leaving the defects and trying to cover them up. Applying a sealant, repellent or tanking will not correct the underlying problem.	+	Brick walls are intended to ‘breath’. They are permeable to moisture and water vapour, and this allows them to dry out if moisture penetrates them from the inside or outside. Any action taken to prevent this can have unforeseen consequences and should not be undertaken without careful consideration. It is always best to try and identify defects and correct them, rather than leaving the defects and trying to cover them up. Applying a sealant, repellent or tanking will not correct the underlying problem.

	The [http://www.brick.org.uk/about-the-brick-development-association/ask-the-expert/ Brick Development Association] states, “We believe the use of sealants and water repellent treatments on brickwork is totally unnecessary and take the view that properly specified and built work performs perfectly satisfactorily in resisting water penetration by wind driven rain, without their need. Brickwork inevitably gets wet in rainy weather and dries out later. This is the way it works and has done so for thousands of years.”		The [http://www.brick.org.uk/about-the-brick-development-association/ask-the-expert/ Brick Development Association] states, “We believe the use of sealants and water repellent treatments on brickwork is totally unnecessary and take the view that properly specified and built work performs perfectly satisfactorily in resisting water penetration by wind driven rain, without their need. Brickwork inevitably gets wet in rainy weather and dries out later. This is the way it works and has done so for thousands of years.”

Designing Buildings at 09:47, 2 February 2017

2017-02-02T09:47:57Z

← Older revision		Revision as of 09:47, 2 February 2017
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		+	[[File:Damp inside a building.jpg]]
		+
	= Introduction =		= Introduction =

Designing Buildings at 09:45, 2 February 2017

2017-02-02T09:45:34Z

← Older revision		Revision as of 09:45, 2 February 2017
Line 1:		Line 1:
	= Introduction =		= Introduction =

−	Traditionally, the external brick walls of buildings were generally constructed without a cavity between the inner and outer leaves, however they were thick enough to prevent moisture penetrating from the outside to the inside.	+	Traditionally, the external brick walls of buildings were generally constructed without a cavity between the inner and outer leaves, however they were thick enough to prevent moisture penetrating from the outside to the inside under most normal circumstances.

	Since the early part of the 20th century, most external brick walls have included a cavity between the inner and outer leaves, meaning that any moisture that penetrates through the outer leave runs down the outer face of the cavity and is drained to the outside.		Since the early part of the 20th century, most external brick walls have included a cavity between the inner and outer leaves, meaning that any moisture that penetrates through the outer leave runs down the outer face of the cavity and is drained to the outside.

−	In both these cases, if moisture ~~penetrates~~ from the outside to the inside, it is generally because there is a defect in the wall construction. It could be that the wall has cracked, or there is a fault in the pointing, or gaps within the mortar, or the coping at the top of the wall is defective, there is a problem with a drain or rainwater downpipe, or the cavity has been breached or poorly filled. There could also be problems with condensation or rising damp that might give the appearance of penetrating damp.	+	In both these cases, if moisture does penetrate from the outside to the inside, it is generally because there is a defect in the wall construction. It could be that the wall has cracked, or there is a fault in the pointing, or gaps within the mortar, or the coping at the top of the wall is defective, there is a problem with a drain or rainwater downpipe, or the cavity has been breached or poorly filled. There could also be problems with condensation or rising damp that might give the appearance of penetrating damp.

	In these situations, the defect should be identified and remedial action taken to correct it.		In these situations, the defect should be identified and remedial action taken to correct it.
Line 15:		Line 15:
	There are two basic approaches for this:		There are two basic approaches for this:

−	* Sealing the brickwork with a non-breathable.	+	* Sealing the brickwork with a non-breathable sealant.
	* Treating the brickwork with a breathable water repellent.		* Treating the brickwork with a breathable water repellent.
−	* Tanking the inside of the brickwork.	+
		+	It is also possible to 'tank' the inside of the brickwork.

	= Non-breathable sealants =		= Non-breathable sealants =

−	~~Sealants~~ can be applied to the external face of ~~the~~ wall ~~were~~ they form a film making it impermeable to moisture. These ~~include~~ acrylics, stearates, urethanes, silicone resins and so on. However, these sealants will generally also make it impermeable to air movement, and will mean that any moisture that does get into the fabric of the wall (such as water vapour from the inside, or interstitial condensation) will not be able to evaporate to the outside. This can leave a wall that is sealed, but nonetheless damp, and at risk from mould growth, frost damage and so on.	+	Non-breathable sealants can be applied to the external face of a wall where they form a film making it impermeable to moisture. These sealants are typically manufactured from materials such as; acrylics, stearates, urethanes, silicone resins and so on. However, these sealants will generally also make the wall impermeable to air movement, and will mean that any moisture that does get into the fabric of the wall (such as water vapour from the inside, or interstitial condensation) will not be able to evaporate to the outside. This can leave a wall that is sealed, but nonetheless damp, and at risk from mould growth, frost damage and so on.

−	~~They~~ are not permanent treatments, and have to be reapplied.	+	Non-breathable sealants are not permanent treatments, and have to be reapplied.

−	~~Note~~, some products described as sealants are actually breathable.	+	Because of the problems they can cause, they are generally not recommended. However, it should be noted that some products described as sealants are actually breathable, or partially breathable, see water repellents below.

	= Water repellents =		= Water repellents =

−	Water repellents can be applied to the external face of ~~the~~ wall~~, which will~~ penetrate through the fabric of the wall, making it repel moisture~~. These include siloxanes, silanes, silicates, methyl siliconates and so on~~. However, the wall remains permeable to air movement, and so water vapour is still able to pass through the wall, reducing the likelihood of a build up of damp from the inside.	+	Water repellents can also be applied to the external face of a wall. They then penetrate through the fabric of the wall, making it repel moisture. However, the wall remains permeable to air movement, and so water vapour is still able to pass through the wall, reducing the likelihood of a build up of damp from the inside. Water repellent treatments include materials such as; siloxanes, silanes, silicates, methyl siliconates and so on.

	As with sealants, they are not permanent treatments, and have to be reapplied. However, as they penetrate into the brickwork, they are less prone to damage, or UV degradation.		As with sealants, they are not permanent treatments, and have to be reapplied. However, as they penetrate into the brickwork, they are less prone to damage, or UV degradation.
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	= Tanking =		= Tanking =

−	The internal face of ~~the wall~~ can be tanked with a waterproof plaster, preventing moisture that penetrates the wall from reaching the inside. However, this may leave the fabric of the wall damp and elements such as joists within the construction may be at risk of deterioration. It can also be difficult to achieve complete tanking, for example where there is a junction between the wall and a floor, or ceiling, and subsequent movement, or works undertaken to the building can breach the tanking.	+	The internal face of walls can be tanked with waterproof plaster, preventing moisture that penetrates the outside of the wall from reaching the inside. However, this may leave the fabric of the wall damp and elements such as joists within the construction may be at risk of deterioration. It can also be difficult to achieve complete tanking, for example where there is a junction between the wall and a floor, or ceiling, and subsequent movement, or works undertaken to the building can breach the tanking.

	Additionally, tanking the inside of the wall means it will not absorb moisture that accumulates inside the building and so the likelihood of internal surface condensation will increase.		Additionally, tanking the inside of the wall means it will not absorb moisture that accumulates inside the building and so the likelihood of internal surface condensation will increase.
Line 44:		Line 45:

	The [http://www.brick.org.uk/about-the-brick-development-association/ask-the-expert/ Brick Development Association] states, “We believe the use of sealants and water repellent treatments on brickwork is totally unnecessary and take the view that properly specified and built work performs perfectly satisfactorily in resisting water penetration by wind driven rain, without their need. Brickwork inevitably gets wet in rainy weather and dries out later. This is the way it works and has done so for thousands of years.”		The [http://www.brick.org.uk/about-the-brick-development-association/ask-the-expert/ Brick Development Association] states, “We believe the use of sealants and water repellent treatments on brickwork is totally unnecessary and take the view that properly specified and built work performs perfectly satisfactorily in resisting water penetration by wind driven rain, without their need. Brickwork inevitably gets wet in rainy weather and dries out later. This is the way it works and has done so for thousands of years.”
		+
		+	The Brick Institute of America however, suggest that the use of water repellant treatments may be appropriate under certain circumstances, if properly considered and applied.

	Whatever solution is adopted, it is likely that action will also be necessary to treat problems inside the building which have been caused by the damp, such as mould, rot, defective plaster and so on.		Whatever solution is adopted, it is likely that action will also be necessary to treat problems inside the building which have been caused by the damp, such as mould, rot, defective plaster and so on.