Cracking and building movement - Revision history

Designing Buildings at 06:37, 28 October 2022

2022-10-28T06:37:26Z

← Older revision		Revision as of 06:37, 28 October 2022
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	[[File:Parapet_wall_cracking.jpg\|link=File:Parapet_wall_cracking.jpg]]		[[File:Parapet_wall_cracking.jpg\|link=File:Parapet_wall_cracking.jpg]]

−	= How to ~~deal with~~ cracks in buildings =	+	= How to repair cracks in buildings =

−	Designers of new buildings ~~may~~ try to ‘design out’ many of the causes that may lead to cracking by careful design of the foundations and superstructure, introducing movement joints, specifying materials that can tolerate movement, and so on.	+	Designers of new buildings will try to ‘design out’ many of the causes that may lead to cracking by careful design of the foundations and superstructure, introducing movement joints, specifying materials that can tolerate movement, and so on. However, some cracking is still possible, particularly in buildings that are newly complete.

−	~~Existing~~ buildings should be examined for the likely cause of movement, and whether this is due to an external factor (such as subsidence), or is caused by the fabric of the building itself ~~(such as a poor grade of cement)~~. It is important to establish whether the cracking is likely to be progressive and to deteriorate further, and if so, to what extent and over what period of time. Research of archival information, such as previous surveys, can help with this assessment.	+	If cracking occurs in buildings, they should first be examined for the likely cause of movement, and assessed to determine whether this is due to an external factor such as subsidence, or is caused by the fabric of the building itself. It is important to establish whether the cracking static, or whether it is likely to be progressive and to deteriorate further, and if so, to what extent and over what period of time. Research of archival information, such as previous surveys or photos, can help with this assessment.

−	Repair strategies can range from ~~major interventions to~~ limited cosmetic works~~. However~~, unless the underlying cause has been dealt with, it is likely that further ~~maintenance~~ work will be required in the future. Movement caused for example by vibration or by thermal expansion and contraction is likely to persist. In this case, repair materials must be chosen carefully; those with the ability to deform in a plastic manner will be more successful than those that simply increase strain around the crack and so are likely to cause the repair to fail.	+	Repair strategies can range from limited cosmetic works to major interventions, however, unless the underlying cause has been dealt with, it is likely that further remedial work will be required in the future. Movement caused for example by vibration or by thermal expansion and contraction is likely to persist. In this case, repair materials must be chosen carefully; those with the ability to deform in a plastic manner will be more successful than those that simply increase strain around the crack and so are likely to cause the repair to fail. For example, hydraulic or fat limes may provide enough plasticity to accommodate strain. Corrosion-resistant stainless steel reinforcements can be inserted into bed joints to reduce the risk of failure by redistributing strain and stress over a wider area.
−		+
−	For example, hydraulic or fat limes may provide enough plasticity to accommodate strain. Corrosion-resistant stainless steel reinforcements can be inserted into bed joints to reduce the risk of failure by redistributing strain and stress over a wider area.	+

	Instruments such as boroscopes can be used to locate voids that may have opened up as a result of movement. Grouting voids to fill them with cementitious material can provide a solution if the underlying cause has been dealt with.		Instruments such as boroscopes can be used to locate voids that may have opened up as a result of movement. Grouting voids to fill them with cementitious material can provide a solution if the underlying cause has been dealt with.
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	Where underpinning of foundations is required, a number of alternative techniques are available. [[Underpinning\|See underpinning for more information.]]		Where underpinning of foundations is required, a number of alternative techniques are available. [[Underpinning\|See underpinning for more information.]]

−	Rather than simply covering up problems, it is important to understand the reason that cracks have occurred, particularly if they are large, or if they are increasing in size, and it may be wise to seek expert advice.	+	Rather than simply covering up problems, it is important to understand the reason that cracks have occurred, particularly if they are large, or if they are increasing in size, and it may be wise to seek expert advice, particularly if there might be implications for structural integrity or safety.

	= Related articles on Designing Buildings =		= Related articles on Designing Buildings =

Designing Buildings at 06:31, 28 October 2022

2022-10-28T06:31:37Z

← Older revision		Revision as of 06:31, 28 October 2022
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	[[File:Cracking.jpg\|link=File:Cracking.jpg]]		[[File:Cracking.jpg\|link=File:Cracking.jpg]]

−	= ~~Introduction~~ =	+	= When should I be concerned about building cracks? =

−	Buildings and other built structures are moving all the time, but usually these movements are so small as to be unnoticeable. ~~Movement~~ can be caused by defects, ~~movement of the~~ ground, foundation ~~failure~~, ~~decay of~~ the building fabric, and so on.	+	Buildings and other built structures are moving all the time, but usually these movements are so small as to be unnoticeable. This movement can be caused by defects, changes in ground conditions, foundation settlement, changes in the building fabric, and so on. However, if the building is unable to accommodate this movement, cracking is likely to occur. The appearance of cracks and other distortions caused by building movement can be visually unattractive and disconcerting for occupants, and if left untreated they can affect the integrity, safety and stability of the structure.

−	~~If a structure is unable to accommodate this movement,~~ cracking ~~is likely to occur~~. ~~The appearance of distortions and cracks~~ can be ~~visually unattractive and disconcerting~~ for ~~occupants, and if left untreated they can affect the integrity, safety and stability of~~ the ~~structure~~.	+	Effective treatment requires first that the causes of the cracking are understood. Only then can a strategy be developed for repairing the problem.

−	~~Effective treatment requires first that~~ the causes of ~~cracking are understood. Only then can a strategy for repair be implemented.~~	+	= What are the most common causes of cracks in buildings? =

−	~~= Causes~~ of cracks =	+	The most common causes of cracks in buildings are:

−	~~The most common causes of cracking are:~~	+	* Ground movement caused by clay shrinkage, land slip, vibration, subsidence, settlement, heave, sway, and so on.
−		+
−	* Ground movement ~~(beneath foundations)~~ caused by clay shrinkage, land slip, vibration, subsidence, settlement, heave, sway, and so on.	+
	* Foundation failure due to the decay of soft clay brick, concrete erosion due to chemical contaminants, and so on.		* Foundation failure due to the decay of soft clay brick, concrete erosion due to chemical contaminants, and so on.
−	* Decay of the building fabric, due to woodworm, rust, and so on.	+	* Decay of the building fabric, due to woodworm, rust, wet rot, dry rot and so on.
−	* Moisture movement that causes materials to expand or contract, ~~perhaps due to~~ the presence of vegetation or faulty or damaged drains.	+	* Moisture movement that causes materials to expand or contract. Excess water, and water penetration can be caused by the presence of vegetation, faulty or damaged drains, flooding, damage to the building fabric, condensation and so on.
	* Thermal movement that causes materials to expand or contract as temperature increases or decreases.		* Thermal movement that causes materials to expand or contract as temperature increases or decreases.
	* Inherent defects, particularly in historic structures.		* Inherent defects, particularly in historic structures.
−	* ~~Faulty or damaged drains.~~	+	* Deformation under excess load.
−	* Suspended structures such as floors that deform under load.	+
	* Tree root growth.		* Tree root growth.
−	* ~~Absence~~ of foundations in older buildings.	+	* The absence of foundations in older buildings.
		+	* Alteration works to the building or neighbouring properties (Note, occupants may see cracks that have been there for some time, but are only noticed when works are taking place).

−	= ~~Size~~ of cracks =	+	= What size of cracks in buildings are significant? =

	BRE assessed a number of properties as part of a study that was published as BRE Digest 251 Assessment of damage in low-rise buildings. This identified six categories of cracks together with the typical damage caused and the remedy required:		BRE assessed a number of properties as part of a study that was published as BRE Digest 251 Assessment of damage in low-rise buildings. This identified six categories of cracks together with the typical damage caused and the remedy required:
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	* 5 – Structural damage: Widths greater than 25 mm. Beams lose their bearing, walls require shoring, and the structure is generally unstable. May require major repair works.		* 5 – Structural damage: Widths greater than 25 mm. Beams lose their bearing, walls require shoring, and the structure is generally unstable. May require major repair works.

−	= ~~Shapes~~ of cracks =	+	= What do the shapes of cracks in buildings mean? =
		+
		+	The shape and orientation of cracks can be an indicator of the cause and seriousness of the problem:

−	* Hairline cracks are common in many buildings, particularly in plaster, which is prone to shrink and is very sensitive to movement.	+	* Hairline cracks are common in many buildings, particularly in plaster, which is prone to shrink and is very sensitive to movement, particularly if the supporting structure is old, or timber frame. The timber frame will move over time, but the plaster will not - and so it cracks.
	* Stepped cracks tend to follow the lines of horizontal and vertical joints in buildings, such as beds of mortar between bricks or blocks and may indicate structural movement.		* Stepped cracks tend to follow the lines of horizontal and vertical joints in buildings, such as beds of mortar between bricks or blocks and may indicate structural movement.
	* Vertical cracks may indicate that structural components such as bricks or blocks have failed and so can be a sign of significant stresses within the building structure.		* Vertical cracks may indicate that structural components such as bricks or blocks have failed and so can be a sign of significant stresses within the building structure.
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	[[File:Parapet_wall_cracking.jpg\|link=File:Parapet_wall_cracking.jpg]]		[[File:Parapet_wall_cracking.jpg\|link=File:Parapet_wall_cracking.jpg]]

−	= ~~Dealing~~ with cracks =	+	= How to deal with cracks in buildings =

	Designers of new buildings may try to ‘design out’ many of the causes that may lead to cracking by careful design of the foundations and superstructure, introducing movement joints, specifying materials that can tolerate movement, and so on.		Designers of new buildings may try to ‘design out’ many of the causes that may lead to cracking by careful design of the foundations and superstructure, introducing movement joints, specifying materials that can tolerate movement, and so on.

Designing Buildings at 06:23, 29 July 2022

2022-07-29T06:23:09Z

← Older revision		Revision as of 06:23, 29 July 2022
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	Rather than simply covering up problems, it is important to understand the reason that cracks have occurred, particularly if they are large, or if they are increasing in size, and it may be wise to seek expert advice.		Rather than simply covering up problems, it is important to understand the reason that cracks have occurred, particularly if they are large, or if they are increasing in size, and it may be wise to seek expert advice.

−	= Related articles on Designing Buildings ~~Wiki:~~ =	+	= Related articles on Designing Buildings =

	* Burland scale.		* Burland scale.
	* Cracking in buildings.		* Cracking in buildings.
		+	* Cyclic stress.
	* Defects in brickwork.		* Defects in brickwork.
	* Defects in construction.		* Defects in construction.

Designing Buildings: Reverted edits by 119.93.119.1 (talk) to last revision by Editor

2022-03-18T09:32:17Z

Reverted edits by 119.93.119.1 (talk) to last revision by Editor

← Older revision		Revision as of 09:32, 18 March 2022
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	* Building Conservation - [http://www.buildingconservation.com/articles/movement/movement.htm Movement]		* Building Conservation - [http://www.buildingconservation.com/articles/movement/movement.htm Movement]
	* Building Conservation - [http://www.buildingconservation.com/articles/cracking/cracking.htm Cracking]		* Building Conservation - [http://www.buildingconservation.com/articles/cracking/cracking.htm Cracking]
−	* ~~BRB~~ - [https://www.bre.co.uk/page.jsp?id=3356 Size of cracks]	+	* BRE - [https://www.bre.co.uk/page.jsp?id=3356 Size of cracks]

−	~~[[Category:Articles_needing_more_work]]~~ [[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:DCN_Project_Knowledge]] [[Category:Health_and_safety_/_CDM]] [[Category:Construction_techniques]]	+	[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:DCN_Project_Knowledge]] [[Category:Health_and_safety_/_CDM]] [[Category:Construction_techniques]]

119.93.119.1 at 09:23, 18 March 2022

2022-03-18T09:23:45Z

← Older revision		Revision as of 09:23, 18 March 2022
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	* Building Conservation - [http://www.buildingconservation.com/articles/movement/movement.htm Movement]		* Building Conservation - [http://www.buildingconservation.com/articles/movement/movement.htm Movement]
	* Building Conservation - [http://www.buildingconservation.com/articles/cracking/cracking.htm Cracking]		* Building Conservation - [http://www.buildingconservation.com/articles/cracking/cracking.htm Cracking]
−	* ~~BRE~~ - [https://www.bre.co.uk/page.jsp?id=3356 Size of cracks]	+	* BRB - [https://www.bre.co.uk/page.jsp?id=3356 Size of cracks]

−	[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:DCN_Project_Knowledge]] [[Category:Health_and_safety_/_CDM]] [[Category:Construction_techniques]]	+	[[Category:Articles_needing_more_work]] [[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:DCN_Project_Knowledge]] [[Category:Health_and_safety_/_CDM]] [[Category:Construction_techniques]]

Editor at 10:43, 2 July 2021

2021-07-02T10:43:02Z

← Older revision		Revision as of 10:43, 2 July 2021
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	* Movement joint.		* Movement joint.
	* Preventing wall collapse.		* Preventing wall collapse.
		+	* Pyrite and mica redress issues in Dail Eireann.
	* Settlement.		* Settlement.
	* Sinkholes.		* Sinkholes.

Designing Buildings at 06:56, 30 August 2020

2020-08-30T06:56:59Z

← Older revision		Revision as of 06:56, 30 August 2020
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	* BRE - [https://www.bre.co.uk/page.jsp?id=3356 Size of cracks]		* BRE - [https://www.bre.co.uk/page.jsp?id=3356 Size of cracks]

−	[[Category:Health_and_safety_/_CDM]] [[Category:Construction_techniques]]	+	[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:DCN_Project_Knowledge]] [[Category:Health_and_safety_/_CDM]] [[Category:Construction_techniques]]

Designing Buildings at 09:40, 7 December 2018

2018-12-07T09:40:52Z

← Older revision		Revision as of 09:40, 7 December 2018
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	Rather than simply covering up problems, it is important to understand the reason that cracks have occurred, particularly if they are large, or if they are increasing in size, and it may be wise to seek expert advice.		Rather than simply covering up problems, it is important to understand the reason that cracks have occurred, particularly if they are large, or if they are increasing in size, and it may be wise to seek expert advice.

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

	* Burland scale.		* Burland scale.
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	* Why do buildings crack? (DG 361).		* Why do buildings crack? (DG 361).

−	=== External references ===	+	= External references =

	* Building Conservation - [http://www.buildingconservation.com/articles/movement/movement.htm Movement]		* Building Conservation - [http://www.buildingconservation.com/articles/movement/movement.htm Movement]

Designing Buildings at 09:40, 7 December 2018

2018-12-07T09:40:33Z

← Older revision		Revision as of 09:40, 7 December 2018
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	Related articles on Designing Buildings Wiki:		Related articles on Designing Buildings Wiki:

−	* ~~Alkali-silica reaction (ASR)~~.	+	* Burland scale.
	* Cracking in buildings.		* Cracking in buildings.
	* Defects in brickwork.		* Defects in brickwork.
	* Defects in construction.		* Defects in construction.
−	* Defects in dot and dab.
	* Defects in stonework.		* Defects in stonework.
−	* Efflorescence.
−	* Foundations.
	* Ground heave.		* Ground heave.
−	* Grouting in civil engineering.
	* Latent defects.		* Latent defects.
	* Leaning Tower of Pisa.		* Leaning Tower of Pisa.
−	* Mould growth in buildings.
	* Movement joint.		* Movement joint.
−	* Pointing.
	* Preventing wall collapse.		* Preventing wall collapse.
−	* Remedial works.
−	* Repointing.
−	* Roofing defects.
	* Settlement.		* Settlement.
	* Sinkholes.		* Sinkholes.
−	* Spalling.
	* Subsidence.		* Subsidence.
−	* Temporary works.
	* Underpinning.		* Underpinning.
	* Why do buildings crack? (DG 361).		* Why do buildings crack? (DG 361).

Editor at 14:50, 22 June 2018

2018-06-22T14:50:24Z

← Older revision		Revision as of 14:50, 22 June 2018
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	Related articles on Designing Buildings Wiki:		Related articles on Designing Buildings Wiki:

		+	* Alkali-silica reaction (ASR).
	* Cracking in buildings.		* Cracking in buildings.
	* Defects in brickwork.		* Defects in brickwork.