Thermal expansion - Revision history

Richard Anthony Johnson at 16:27, 4 April 2024

2024-04-04T16:27:09Z

← Older revision		Revision as of 16:27, 4 April 2024
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	In the UK, the typical seasonal variations in temperature – i.e between a hot summer’s day and a cold winter’s night – can be as much as 30°C. This can induce strain and damage a building. When materials are restrained excessively and cannot expand, the release of built-up internal stresses can result in cracking, bowing, buckling and other forms of deformation. For example, in brickwork, thermal expansion can cause cracking of both mortar and bricks, allowing rainwater to penetrate through the external leaf.		In the UK, the typical seasonal variations in temperature – i.e between a hot summer’s day and a cold winter’s night – can be as much as 30°C. This can induce strain and damage a building. When materials are restrained excessively and cannot expand, the release of built-up internal stresses can result in cracking, bowing, buckling and other forms of deformation. For example, in brickwork, thermal expansion can cause cracking of both mortar and bricks, allowing rainwater to penetrate through the external leaf.
		+
		+	Long wall panels to low rise buildings such as Bungalows/ single storey masonry structures will "slide" along the DPC. Predominant in structures formed during the 1940's and 1950's, brickwork either end of the wall panel may "overhang" masonry below the DPC.

	Expansion joints usually prevent this happening.		Expansion joints usually prevent this happening.

	In brickwork, 10mm-wide vertical expansion joints filled with a suitable filler material can allow for thermal expansion and are typically installed every 10m-12m for main walling runs. But in freestanding walls and parapets, this is usually reduced to 6m-8m because these constructions are typically more exposed to the elements and have less weight above them (and therefore less restraint).		In brickwork, 10mm-wide vertical expansion joints filled with a suitable filler material can allow for thermal expansion and are typically installed every 10m-12m for main walling runs. But in freestanding walls and parapets, this is usually reduced to 6m-8m because these constructions are typically more exposed to the elements and have less weight above them (and therefore less restraint).
		+
		+	Thermal expansion in masonry wall panels with large openings or openings that result in a reduced wall panel size locally may exhibit cracks forming as a result of a "stress concentration", particaularly if the elevaiton is south facing.

	Movement in the vertical plane should also be considered and accommodated with a horizontal movement joint (sometimes referred to as a ‘soft joint’) at the appropriate spacing.		Movement in the vertical plane should also be considered and accommodated with a horizontal movement joint (sometimes referred to as a ‘soft joint’) at the appropriate spacing.

Designing Buildings at 07:54, 30 August 2022

2022-08-30T07:54:09Z

← Older revision		Revision as of 07:54, 30 August 2022
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	Expansion joints are typically filled with a material capable of being compressed by up to around 50% of its original thickness and which can recover after the thermal movement is reversed.		Expansion joints are typically filled with a material capable of being compressed by up to around 50% of its original thickness and which can recover after the thermal movement is reversed.

−	NB [https://www.ipcc.ch/report/ar5/wg2/ AR5 Climate Change 2014: Impacts, Adaptation, and Vulnerability, Glossary], published by the Intergovernmental Panel on Climate Change (IPCC) ~~state~~ in relation to thermal expansion: ‘In connection with sea level, this refers to the increase in volume (and decrease in density) that results from warming water. A warming of the ocean leads to an expansion of the ocean volume and hence an increase in sea level.’	+	NB [https://www.ipcc.ch/report/ar5/wg2/ AR5 Climate Change 2014: Impacts, Adaptation, and Vulnerability, Glossary], published by the Intergovernmental Panel on Climate Change (IPCC) states in relation to thermal expansion: ‘In connection with sea level, this refers to the increase in volume (and decrease in density) that results from warming water. A warming of the ocean leads to an expansion of the ocean volume and hence an increase in sea level.’

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

Designing Buildings at 07:53, 30 August 2022

2022-08-30T07:53:32Z

← Older revision		Revision as of 07:53, 30 August 2022
Line 19:		Line 19:
	Expansion joints are typically filled with a material capable of being compressed by up to around 50% of its original thickness and which can recover after the thermal movement is reversed.		Expansion joints are typically filled with a material capable of being compressed by up to around 50% of its original thickness and which can recover after the thermal movement is reversed.

−	= Related articles on Designing Buildings ~~Wiki~~ =	+	NB [https://www.ipcc.ch/report/ar5/wg2/ AR5 Climate Change 2014: Impacts, Adaptation, and Vulnerability, Glossary], published by the Intergovernmental Panel on Climate Change (IPCC) state in relation to thermal expansion: ‘In connection with sea level, this refers to the increase in volume (and decrease in density) that results from warming water. A warming of the ocean leads to an expansion of the ocean volume and hence an increase in sea level.’
		+
		+	= Related articles on Designing Buildings =

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

−	[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:Construction_techniques]] [[Category:Products_/_components]]	+	[[Category:DCN_Definition]] [[Category:DCN_Guidance]] [[Category:Construction_techniques]] [[Category:Products_/_components]] [[Category:Disambiguation]]

Designing Buildings at 06:51, 14 January 2021

2021-01-14T06:51:14Z

← Older revision		Revision as of 06:51, 14 January 2021
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	* Why do buildings crack? (DG 361).		* Why do buildings crack? (DG 361).

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

Editor: Reverted edits by 193.133.28.125 (talk) to last revision by Designing Buildings

2020-01-28T10:50:05Z

Reverted edits by 193.133.28.125 (talk) to last revision by Designing Buildings

← Older revision		Revision as of 10:50, 28 January 2020
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	Knowing the coefficients of expansion allows designers to calculate how much thermal movement to accommodate (particularly on a hot summer’s day when there are solar heat gains will be higher) by allowing for expansion joints.		Knowing the coefficients of expansion allows designers to calculate how much thermal movement to accommodate (particularly on a hot summer’s day when there are solar heat gains will be higher) by allowing for expansion joints.

−	Thermal movements tend to be reversible, i.e for every millimetre of expansion, there will usually be the same ~~amou~~	+	Thermal movements tend to be reversible, i.e for every millimetre of expansion, there will usually be the same amount of contraction as the temperature drops.
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−	nt of contraction as the temperature drops.	+

	In the UK, the typical seasonal variations in temperature – i.e between a hot summer’s day and a cold winter’s night – can be as much as 30°C. This can induce strain and damage a building. When materials are restrained excessively and cannot expand, the release of built-up internal stresses can result in cracking, bowing, buckling and other forms of deformation. For example, in brickwork, thermal expansion can cause cracking of both mortar and bricks, allowing rainwater to penetrate through the external leaf.		In the UK, the typical seasonal variations in temperature – i.e between a hot summer’s day and a cold winter’s night – can be as much as 30°C. This can induce strain and damage a building. When materials are restrained excessively and cannot expand, the release of built-up internal stresses can result in cracking, bowing, buckling and other forms of deformation. For example, in brickwork, thermal expansion can cause cracking of both mortar and bricks, allowing rainwater to penetrate through the external leaf.
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	* Why do buildings crack? (DG 361).		* Why do buildings crack? (DG 361).

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

193.133.28.125 at 10:16, 28 January 2020

2020-01-28T10:16:25Z

← Older revision		Revision as of 10:16, 28 January 2020
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	Knowing the coefficients of expansion allows designers to calculate how much thermal movement to accommodate (particularly on a hot summer’s day when there are solar heat gains will be higher) by allowing for expansion joints.		Knowing the coefficients of expansion allows designers to calculate how much thermal movement to accommodate (particularly on a hot summer’s day when there are solar heat gains will be higher) by allowing for expansion joints.

−	Thermal movements tend to be reversible, i.e for every millimetre of expansion, there will usually be the same ~~amount~~ of contraction as the temperature drops.	+	Thermal movements tend to be reversible, i.e for every millimetre of expansion, there will usually be the same amou
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		+	nt of contraction as the temperature drops.

	In the UK, the typical seasonal variations in temperature – i.e between a hot summer’s day and a cold winter’s night – can be as much as 30°C. This can induce strain and damage a building. When materials are restrained excessively and cannot expand, the release of built-up internal stresses can result in cracking, bowing, buckling and other forms of deformation. For example, in brickwork, thermal expansion can cause cracking of both mortar and bricks, allowing rainwater to penetrate through the external leaf.		In the UK, the typical seasonal variations in temperature – i.e between a hot summer’s day and a cold winter’s night – can be as much as 30°C. This can induce strain and damage a building. When materials are restrained excessively and cannot expand, the release of built-up internal stresses can result in cracking, bowing, buckling and other forms of deformation. For example, in brickwork, thermal expansion can cause cracking of both mortar and bricks, allowing rainwater to penetrate through the external leaf.

Designing Buildings at 14:39, 18 December 2019

2019-12-18T14:39:51Z

← Older revision		Revision as of 14:39, 18 December 2019
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−	~~= Introduction =~~	+	Variations in the temperature of a structure can result in thermal movements of its constituent parts. Most building materials will expand with rises in temperature caused (in most cases) by solar heat gains. In many solid materials (i.e not liquids), the expansion will usually be greater along the long dimension of the material as opposed to the short. Liquids tend to expand in all directions when heated.

−	~~Variations in the temperature~~ of ~~a structure and its parts can result in~~ thermal ~~movements of its constituent parts~~. ~~Most building materials will expand with rises in temperature caused (in most cases) by solar heat gains. In many solid materials (i.e not liquids)~~, ~~the expansion will usually be greater along the long dimension~~ of the material ~~as opposed to the short, thus this is usually accommodated in the design detailing. Liquids tend to expand in all directions when heated~~. The degree to which solid materials expand is ~~given~~ by ~~the~~ coefficient of linear thermal expansion (CLTE).	+	Different materials are likely to have different rates of thermal expansion. Indeed, it is possible for variations to exist even among samples of the same material. The degree to which solid materials expand as a result of temperature change is expressed by their coefficient of linear thermal expansion (CLTE). The expansion of a material can be calculated from the percentage change in its length per degree of temperature change, its length, and the change in temperature.

−	When considering the coefficient of thermal linear expansion, it is important to know the percentage change in the length of the material per degree of temperature change. Multiplied together they will give the total expansion. Thus, the degree of movement will depend on:	+	Knowing the coefficients of expansion allows designers to calculate how much thermal movement to accommodate (particularly on a hot summer’s day when there are solar heat gains will be higher) by allowing for expansion joints.
−		+
−	* The coefficient of thermal expansion of the affected materials	+
−	* The temperature increase or variation in a given period.	+
−		+
−	~~These factors give an idea of how materials will change in shape with changing temperatures.~~ Knowing the coefficients of expansion allows designers to calculate how much thermal movement ~~will take place~~ (particularly on a hot summer’s day when there are solar heat gains will be higher)~~. This allows design~~ for ~~worst-case scenarios and can determine the maximum width of~~ expansion joints.	+
−		+
−	In the UK, the typical seasonal variations in temperature – i.e between a hot summer’s day and a cold winter’s night – can be as much as 30°C. materials must therefore be able to accommodate a wide range of temperatures. Even daily diurnal temperatures can induce strain and damage a building: in brickwork, thermal expansion can cause cracking of both mortar and bricks, allowing rainwater to penetrate through the external leaf. When materials are restrained excessively and cannot expand, the release of built-up internal stresses can result in cracking, bowing, buckling and other forms of deformation. Expansion joints usually prevent this happening.	+

	Thermal movements tend to be reversible, i.e for every millimetre of expansion, there will usually be the same amount of contraction as the temperature drops.		Thermal movements tend to be reversible, i.e for every millimetre of expansion, there will usually be the same amount of contraction as the temperature drops.

−	~~Different~~ materials are ~~likely to have different rates~~ of thermal expansion~~. Indeed~~, ~~it is possible for variations~~ to ~~exist even among samples of~~ the ~~same material~~.	+	In the UK, the typical seasonal variations in temperature – i.e between a hot summer’s day and a cold winter’s night – can be as much as 30°C. This can induce strain and damage a building. When materials are restrained excessively and cannot expand, the release of built-up internal stresses can result in cracking, bowing, buckling and other forms of deformation. For example, in brickwork, thermal expansion can cause cracking of both mortar and bricks, allowing rainwater to penetrate through the external leaf.

−	~~=== Brickwork ===~~	+	Expansion joints usually prevent this happening.

−	In brickwork, 10mm-wide vertical expansion joints filled with a suitable filler material can ~~form the joint~~ for thermal expansion and are typically installed every 10m-12m for main walling runs. But in freestanding walls and parapets, this is usually reduced to 6m-8m because these constructions are typically:	+	In brickwork, 10mm-wide vertical expansion joints filled with a suitable filler material can allow for thermal expansion and are typically installed every 10m-12m for main walling runs. But in freestanding walls and parapets, this is usually reduced to 6m-8m because these constructions are typically more exposed to the elements and have less weight above them (and therefore less restraint).
−		+
−	* More exposed to the elements	+
−	* Usually have less weight above them (and therefore less restraint) ~~than main walling runs~~.	+

	Movement in the vertical plane should also be considered and accommodated with a horizontal movement joint (sometimes referred to as a ‘soft joint’) at the appropriate spacing.		Movement in the vertical plane should also be considered and accommodated with a horizontal movement joint (sometimes referred to as a ‘soft joint’) at the appropriate spacing.

−	~~=== Roofs ===~~	+	Lead, zinc and copper can be formed (in roof applications) with traditional ‘drips’ which are steps that break up the length and accommodate thermal expansion. Alternatively, a rubber (neoprene) expansion joint can be used.
−		+
−	In cold roofs, where insulation is directly above the ceiling making the roof structure more exposed to solar heat gain, the construction may suffer from excessive thermal movement and cause cracking to ceiling finishes if not detailed properly.	+
−		+
−	~~=== Metals ===~~	+
−		+
−	Lead, zinc and copper can be formed (in roof applications) with traditional ‘drips’ which are steps that break up the length ~~if runs~~ and accommodate thermal expansion. Alternatively, a rubber (neoprene) expansion joint can be used.	+
−		+
−	~~= Materials for expansion joints =~~	+

−	Expansion joints are typically filled with a ~~compressible~~ material capable of being compressed up to around 50% of its original thickness and which can recover after the thermal movement is reversed.	+	Expansion joints are typically filled with a material capable of being compressed by up to around 50% of its original thickness and which can recover after the thermal movement is reversed.

	= Related articles on Designing Buildings Wiki =		= Related articles on Designing Buildings Wiki =
Line 46:		Line 28:
	* Ground heave.		* Ground heave.
	* Latent defects.		* Latent defects.
−	* Leaning Tower of Pisa.
	* Movement joint.		* Movement joint.
	* Preventing wall collapse.		* Preventing wall collapse.
−	* ~~Settlement.~~	+	* Solar radiation.
−	* Sinkholes.	+
−	* Subsidence.	+
−	* Underpinning.	+
	* Why do buildings crack? (DG 361).		* Why do buildings crack? (DG 361).

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

Editor: Created page with "= Introduction = Variations in the temperature of a structure and its parts can result in thermal movements of its constituent parts. Most building materials will expand with ri..."

2019-12-12T18:29:42Z

Created page with "= Introduction = Variations in the temperature of a structure and its parts can result in thermal movements of its constituent parts. Most building materials will expand with ri..."

New page

= Introduction =

Variations in the temperature of a structure and its parts can result in thermal movements of its constituent parts. Most building materials will expand with rises in temperature caused (in most cases) by solar heat gains. In many solid materials (i.e not liquids), the expansion will usually be greater along the long dimension of the material as opposed to the short, thus this is usually accommodated in the design detailing. Liquids tend to expand in all directions when heated. The degree to which solid materials expand is given by the coefficient of linear thermal expansion (CLTE).

When considering the coefficient of thermal linear expansion, it is important to know the percentage change in the length of the material per degree of temperature change. Multiplied together they will give the total expansion. Thus, the degree of movement will depend on:

* The coefficient of thermal expansion of the affected materials
* The temperature increase or variation in a given period.

These factors give an idea of how materials will change in shape with changing temperatures. Knowing the coefficients of expansion allows designers to calculate how much thermal movement will take place (particularly on a hot summer’s day when there are solar heat gains will be higher). This allows design for worst-case scenarios and can determine the maximum width of expansion joints.

In the UK, the typical seasonal variations in temperature – i.e between a hot summer’s day and a cold winter’s night – can be as much as 30°C. materials must therefore be able to accommodate a wide range of temperatures. Even daily diurnal temperatures can induce strain and damage a building: in brickwork, thermal expansion can cause cracking of both mortar and bricks, allowing rainwater to penetrate through the external leaf. When materials are restrained excessively and cannot expand, the release of built-up internal stresses can result in cracking, bowing, buckling and other forms of deformation. Expansion joints usually prevent this happening.

Thermal movements tend to be reversible, i.e for every millimetre of expansion, there will usually be the same amount of contraction as the temperature drops.

Different materials are likely to have different rates of thermal expansion. Indeed, it is possible for variations to exist even among samples of the same material.

=== Brickwork ===

In brickwork, 10mm-wide vertical expansion joints filled with a suitable filler material can form the joint for thermal expansion and are typically installed every 10m-12m for main walling runs. But in freestanding walls and parapets, this is usually reduced to 6m-8m because these constructions are typically:

* More exposed to the elements
* Usually have less weight above them (and therefore less restraint) than main walling runs.

Movement in the vertical plane should also be considered and accommodated with a horizontal movement joint (sometimes referred to as a ‘soft joint’) at the appropriate spacing.

=== Roofs ===

In cold roofs, where insulation is directly above the ceiling making the roof structure more exposed to solar heat gain, the construction may suffer from excessive thermal movement and cause cracking to ceiling finishes if not detailed properly.

=== Metals ===

Lead, zinc and copper can be formed (in roof applications) with traditional ‘drips’ which are steps that break up the length if runs and accommodate thermal expansion. Alternatively, a rubber (neoprene) expansion joint can be used.

= Materials for expansion joints =

Expansion joints are typically filled with a compressible material capable of being compressed up to around 50% of its original thickness and which can recover after the thermal movement is reversed.

= Related articles on Designing Buildings Wiki =

* Burland scale.
* Cracking in buildings.
* Defects in brickwork.
* Defects in construction.
* Defects in stonework.
* Ground heave.
* Latent defects.
* Leaning Tower of Pisa.
* Movement joint.
* Preventing wall collapse.
* Settlement.
* Sinkholes.
* Subsidence.
* Underpinning.
* Why do buildings crack? (DG 361).

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