Pattern staining and soiling in stonework - Revision history

Designing Buildings at 06:37, 11 November 2020

2020-11-11T06:37:20Z

← Older revision		Revision as of 06:37, 11 November 2020
Line 94:		Line 94:
	* Wall tie failure.		* Wall tie failure.

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

Gary Yeardley Touyz at 14:58, 30 April 2020

2020-04-30T14:58:53Z

← Older revision		Revision as of 14:58, 30 April 2020
Line 75:		Line 75:
	Prevention measures (such as sealants) are not always ideal and can be more damaging in the long-term. Staining and weathering to masonry can add to the aesthetic appeal of a building but careful consideration should be exercised in assessing whether that appeal is at the expense of structural integrity.		Prevention measures (such as sealants) are not always ideal and can be more damaging in the long-term. Staining and weathering to masonry can add to the aesthetic appeal of a building but careful consideration should be exercised in assessing whether that appeal is at the expense of structural integrity.

−	--[[User:~~Gary_Yeardley~~\|Gary Yeardley]]	+	--[[User:Gary_Yeardley_Touyz\|Gary Yeardley]]

	= Related articles on Designing Buildings Wiki =		= Related articles on Designing Buildings Wiki =
Line 94:		Line 94:
	* Wall tie failure.		* Wall tie failure.

−	[[Category:Client_procedures]] [[Category:Design]] [[Category:Procurement]] [[Category:Products_/_components]]	+	[[Category:Client_procedures]] [[Category:Design]] [[Category:Procurement]] [[Category:Products_/_components]] [[Category:DCN_Product_Knowledge]]

Editor at 14:58, 11 October 2018

2018-10-11T14:58:59Z

← Older revision		Revision as of 14:58, 11 October 2018
Line 61:		Line 61:
	== Organic biological growths ==		== Organic biological growths ==

−	Organic growth, such as the growth of moss, lichen, and algae tend to affect the transpiration rate of materials (they absorb rainwater, preventing drainage). This presence of organic growth offers a moist bed which may promote the growth of damaging creeper plants (such as ivy). Ivy has been known to cause cracks in masonry and mortar. This is especially damaging in cold weather as the cracks filled with moisture may freeze and the expansion during the freezing process can cause further cracking and / or spalling.	+	Organic growth, such as the growth of moss, lichen, and algae tend to affect the transpiration rate of materials (they absorb rainwater, preventing drainage). This presence of organic growth offers a moist bed which may promote the growth of damaging creeper plants (such as ivy). Ivy has been known to cause cracks in masonry and mortar. This is especially damaging in cold weather as the cracks filled with moisture may freeze and the expansion during the freezing process can cause further cracking and/or spalling.

	[[File:2222.jpg\|link=File:2222.jpg]]		[[File:2222.jpg\|link=File:2222.jpg]]
Line 77:		Line 77:
	--[[User:Gary_Yeardley\|Gary Yeardley]]		--[[User:Gary_Yeardley\|Gary Yeardley]]

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

	* Damp.		* Damp.
Line 93:		Line 91:
	* Settlement.		* Settlement.
	* Solid wall insulation.		* Solid wall insulation.
		+	* Stain.
	* Wall tie failure.		* Wall tie failure.

	[[Category:Client_procedures]] [[Category:Design]] [[Category:Procurement]] [[Category:Products_/_components]]		[[Category:Client_procedures]] [[Category:Design]] [[Category:Procurement]] [[Category:Products_/_components]]

Designing Buildings at 06:46, 2 September 2018

2018-09-02T06:46:02Z

← Older revision		Revision as of 06:46, 2 September 2018
Line 75:		Line 75:
	Prevention measures (such as sealants) are not always ideal and can be more damaging in the long-term. Staining and weathering to masonry can add to the aesthetic appeal of a building but careful consideration should be exercised in assessing whether that appeal is at the expense of structural integrity.		Prevention measures (such as sealants) are not always ideal and can be more damaging in the long-term. Staining and weathering to masonry can add to the aesthetic appeal of a building but careful consideration should be exercised in assessing whether that appeal is at the expense of structural integrity.

−	~~Author~~: Gary Yeardley ~~MRICS [2015~~]	+	--[[User:Gary_Yeardley\|Gary Yeardley]]

	= Find out more =		= Find out more =

Gary Yeardley at 13:37, 31 August 2018

2018-08-31T13:37:54Z

← Older revision		Revision as of 13:37, 31 August 2018
Line 67:		Line 67:
	The presence of moss may be especially damaging to tiled roofs where moss facilitates moisture ingress into timber batons causing premature decay. Moss may also fall, or spread into gutters which can lead to them overflowing. Mosses are known to secrete acids, which can etch into some stones causing decay.		The presence of moss may be especially damaging to tiled roofs where moss facilitates moisture ingress into timber batons causing premature decay. Moss may also fall, or spread into gutters which can lead to them overflowing. Mosses are known to secrete acids, which can etch into some stones causing decay.

−	Maintenance will limit and prevent further organic growth. Using sealants on clay tiled, or any tiles roofs should be discouraged. If biological growth is present, then it should first be determined ~~whetherit~~ actually presents a risk to the building’s integrity prior to treatment as the rectification process may prove more damaging than the original growth.	+	Maintenance will limit and prevent further organic growth. Using sealants on clay tiled, or any tiles roofs should be discouraged. If biological growth is present, then it should first be determined whether it actually presents a risk to the building’s integrity prior to treatment as the rectification process may prove more damaging than the original growth.

	= Conclusion =		= Conclusion =
Line 74:		Line 74:

	Prevention measures (such as sealants) are not always ideal and can be more damaging in the long-term. Staining and weathering to masonry can add to the aesthetic appeal of a building but careful consideration should be exercised in assessing whether that appeal is at the expense of structural integrity.		Prevention measures (such as sealants) are not always ideal and can be more damaging in the long-term. Staining and weathering to masonry can add to the aesthetic appeal of a building but careful consideration should be exercised in assessing whether that appeal is at the expense of structural integrity.
		+
		+	Author: Gary Yeardley MRICS [2015]

	= Find out more =		= Find out more =

Editor at 15:05, 17 April 2018

2018-04-17T15:05:56Z

← Older revision		Revision as of 15:05, 17 April 2018
Line 25:		Line 25:
	== Pollution and acid rain ==		== Pollution and acid rain ==

−	Soot and dirt in the atmosphere from chimneys, motor vehicles etc, can settle on masonry. Certain pollutants (such as bird droppings, mineral, or vegetable deposits) can contain acidic components or soluble salts, which can deposit directly on stone causing staining and /or erosion.	+	Soot and dirt in the atmosphere from chimneys, motor vehicles etc, can settle on masonry. Certain pollutants (such as bird droppings, mineral, or vegetable deposits) can contain acidic components or soluble salts, which can deposit directly on stone causing staining and/or erosion.

	Pollution may mix with rainwater in the atmosphere creating acid rain. Acid rain coming into contact with the a stone surface tends to produce gypsum by a chemical reaction. This allows dirt and soot to bond to stone surfaces, causing staining. In open areas, normal rainwater may wash away the staining; however, in sheltered areas with limited access to fresh water, an impermeable skin can form from the acid rain and result in cavitation of stone material.		Pollution may mix with rainwater in the atmosphere creating acid rain. Acid rain coming into contact with the a stone surface tends to produce gypsum by a chemical reaction. This allows dirt and soot to bond to stone surfaces, causing staining. In open areas, normal rainwater may wash away the staining; however, in sheltered areas with limited access to fresh water, an impermeable skin can form from the acid rain and result in cavitation of stone material.
Line 85:		Line 85:
	* How to clean masonry.		* How to clean masonry.
	* Interstitial condensation.		* Interstitial condensation.
		+	* Lime run-off.
	* Mould growth.		* Mould growth.
	* Penetrating damp.		* Penetrating damp.

Editor at 15:00, 6 September 2017

2017-09-06T15:00:13Z

← Older revision		Revision as of 15:00, 6 September 2017
Line 17:		Line 17:
	== Rainwater ==		== Rainwater ==

−	Typical materials used in the construction of period buildings, such as; limestone, flint, timber, lead, cast iron, and clay are able to withstand rainfall by either being impermeable or having a natural absorption / expulsion process. These processes depend on adequate exposure to the sun and good ventilation. However, too much rainwater,such as from overflowing gutters or down pipes,can exhaust the material’s adaptive processes. Accordingly, masonry areas that are poorly ventilated, lack sunlight, or become oversaturated from rainwater can darken and stain. Stains develop deeper in materials the longer they remain oversaturated becoming more difficult to eradicate. Surrounding mortar will begin to lose strength and be more easily washed away, thus compromising structural integrity.	+	Typical materials used in the construction of period buildings, such as; limestone, flint, timber, lead, cast iron, and clay are able to withstand rainfall by either being impermeable or having a natural absorption / expulsion process. These processes depend on adequate exposure to the sun and good ventilation. However, too much rainwater,such as from overflowing gutters or down pipes,can exhaust the material’s adaptive processes.
		+
		+	Accordingly, masonry areas that are poorly ventilated, lack sunlight, or become oversaturated from rainwater can darken and stain. Stains develop deeper in materials the longer they remain oversaturated becoming more difficult to eradicate. Surrounding mortar will begin to lose strength and be more easily washed away, thus compromising structural integrity.

	Clay tiles are a common foundation for the growth of moss. Moss can be cleaned away from the surface but it would advisable to avoid using sealants that many tradesmen will promote. The types of sealants typically used may trap in moisture and seal in unwanted foreign particles that have not been adequately cleaned away. Building materials should be able to breathe,allowing moisture absorption and subsequent evaporation.		Clay tiles are a common foundation for the growth of moss. Moss can be cleaned away from the surface but it would advisable to avoid using sealants that many tradesmen will promote. The types of sealants typically used may trap in moisture and seal in unwanted foreign particles that have not been adequately cleaned away. Building materials should be able to breathe,allowing moisture absorption and subsequent evaporation.
Line 23:		Line 25:
	== Pollution and acid rain ==		== Pollution and acid rain ==

−	Soot and dirt in the atmosphere from chimneys, motor vehicles etc, can settle on masonry. Certain pollutants (such as bird droppings, mineral, or vegetable deposits) can contain acidic components or soluble salts, which can deposit directly on stone causing staining and /or erosion. Pollution may mix with rainwater in the atmosphere creating acid rain. Acid rain coming into contact with the a stone surface tends to produce gypsum by a chemical reaction. This allows dirt and soot to bond to stone surfaces, causing staining. In open areas, normal rainwater may wash away the staining; however, in sheltered areas with limited access to fresh water, an impermeable skin can form from the acid rain and result in cavitation of stone material.	+	Soot and dirt in the atmosphere from chimneys, motor vehicles etc, can settle on masonry. Certain pollutants (such as bird droppings, mineral, or vegetable deposits) can contain acidic components or soluble salts, which can deposit directly on stone causing staining and /or erosion.
		+
		+	Pollution may mix with rainwater in the atmosphere creating acid rain. Acid rain coming into contact with the a stone surface tends to produce gypsum by a chemical reaction. This allows dirt and soot to bond to stone surfaces, causing staining. In open areas, normal rainwater may wash away the staining; however, in sheltered areas with limited access to fresh water, an impermeable skin can form from the acid rain and result in cavitation of stone material.

	Acid rain can cause corrosion staining to run off lead. Lead materials such as flashing, may well be joining a stone wall and the run off can stain the stone.		Acid rain can cause corrosion staining to run off lead. Lead materials such as flashing, may well be joining a stone wall and the run off can stain the stone.
Line 79:		Line 83:
	* Defects in dot and dab.		* Defects in dot and dab.
	* Defects in stonework.		* Defects in stonework.
		+	* How to clean masonry.
	* Interstitial condensation.		* Interstitial condensation.
	* Mould growth.		* Mould growth.

Designing Buildings at 11:23, 4 December 2015

2015-12-04T11:23:26Z

Designing Buildings at 11:21, 4 December 2015

2015-12-04T11:21:29Z

Designing Buildings at 11:15, 4 December 2015

2015-12-04T11:15:51Z

← Older revision		Revision as of 11:15, 4 December 2015
Line 1:		Line 1:
		+	= Introduction =

−	~~= '''Introduction''' =~~	+	Stone is a tremendous material used in the construction of many period properties. With time, stonework weathers which arguably contributes to the overall character and appeal. Although naturally resistant, stone and other materials typically used in construction must be adequately maintained.

−	Stone is a tremendous material used in the construction of many period properties. With time, stonework weathers which arguably contributes to the overall character and appeal. Although naturally resistant, stone and other materials typically used in construction must be adequately maintained. Worryingly, the likes of sandblasting, chemical treatments, sealants and repointing with inappropriate materials are becoming increasingly common. Many are inappropriately sold by inexperienced tradesmen and the long-term effects ~~could be~~ damaging. Caution should be exercised and a professional opinion ought to be sought by anyone looking at cleaning stone or associated materials.	+	Worryingly, the likes of sandblasting, chemical treatments, sealants and repointing with inappropriate materials are becoming increasingly common. Many are inappropriately sold by inexperienced tradesmen and the long-term effects canbe damaging. Caution should be exercised and a professional opinion ought to be sought by anyone looking at cleaning stone or associated materials.

−	= ~~'''~~An overview of pattern staining and soiling ~~'''~~ =	+	= An overview of pattern staining and soiling =

−	Pattern staining ~~is when~~ foreign composite settles or emerges on the (internal or ~~external) surface~~ of a material. There are various causes of pattern staining, such as pollution deposition, salt expulsion, staining from other materials, etc. Algae soiling is a random growth on buildings that is caused by organic biological deposition on surfaces, such as moss and lichens. Staining and soiling can sometimes be seen as adding character to buildings; however, others argue that they are unsightly. Usually, these cause detriment to building surfaces, and ought to be rectified.	+	Pattern staining occurswhen a foreign composite settles or emerges on the internal or externalsurface of a material.

−	~~= '''The most likely~~ causes ~~''' =~~	+	There are various causes of pattern staining, such as pollution deposition, salt expulsion, staining from other materials, and so on. Algae soiling is a random growth on buildings that is caused by organic biological deposition on surfaces, such as moss and lichens.
−	~~'''Rainwater ''' ==~~	+

−	~~Typical materials used in the construction of period~~ buildings~~, such as~~; ~~limestone~~, ~~flint, timber, lead, cast iron, and clay~~ are ~~able to withstand rainfall by either being impermeable or having a natural absorption/expulsion process~~. ~~These processes depend on adequate sun exposure and ventilation. Further~~, ~~too much rainwater (eg overflowing gutters/downpipes) can exhaust the material’s adaptive processes. Accordingly~~, ~~masonry areas that are poorly ventilated, lack sunlight, or become oversaturated from rainwater can darken~~ and ~~stain. Stains develop deeper in materials the longer they remain oversaturated becoming more difficult~~ to ~~eradicate. Surrounding mortar will begin to lose strength and~~ be ~~more easily washed away, thus compromising structural integrity~~.	+	Staining and soiling can sometimes be seen as adding character to buildings; however, others argue that they are unsightly. Usually, these cause detriment to building surfaces, and ought to be rectified.

−	~~Clay tiles are a common foundation for the growth of moss. Moss can be cleaned away from the surface but it would advisable to avoid sealant that many tradesmen will promote.~~ The types of sealants typically used may trap in moisture and seal in unwanted foreign particles that have not been adequately cleaned away. Building materials should be able to breathe allowing moisture absorption and subsequent evaporation.	+	= The most likely causes =

−	== ~~'''Pollution and acid rain'''~~ ==	+	== Rainwater ==

−	Soot and dirt in the atmosphere from chimneys, motor vehicles etc, can settle on masonry. Certain pollutions (such as bird droppings, mineral, or vegetable deposits) can contain acidic components or soluble salts, which can deposit directly on stone causing staining and/or erosion. Pollution may mix with rainwater in the atmosphere creating acid rain. Acid rain coming into contact with the a stone surface tends to produce gypsum by a chemical reaction. This allows dirt and soot to bond to stone surfaces, causing staining. In open areas, normal rainwater may wash away the staining; however, in sheltered areas with limited access to fresh water, an impermeable skin can form from the acid rain and result in cavitation of stone material.	+	Typical materials used in the construction of period buildings, such as; limestone, flint, timber, lead, cast iron, and clay are able to withstand rainfall by either being impermeable or having a natural absorption / expulsion process. These processes depend on adequate exposure to the sun and good ventilation. However, too much rainwater,such as fromoverflowing guttersordownpipes,can exhaust the material’s adaptive processes. Accordingly, masonry areas that are poorly ventilated, lack sunlight, or become oversaturated from rainwater can darken and stain. Stains develop deeper in materials the longer they remain oversaturated becoming more difficult to eradicate. Surrounding mortar will begin to lose strength and be more easily washed away, thus compromising structural integrity.
		+
		+	Clay tiles are a common foundation for the growth of moss. Moss can be cleaned away from the surface but it would advisable to avoid using sealants that many tradesmen will promote. The types of sealants typically used may trap in moisture and seal in unwanted foreign particles that have not been adequately cleaned away. Building materials should be able to breathe,allowing moisture absorption and subsequent evaporation.
		+
		+	== Pollution and acid rain ==
		+
		+	Soot and dirt in the atmosphere from chimneys, motor vehicles etc, can settle on masonry. Certain pollutions (such as bird droppings, mineral, or vegetable deposits) can contain acidic components or soluble salts, which can deposit directly on stone causing staining and /or erosion. Pollution may mix with rainwater in the atmosphere creating acid rain. Acid rain coming into contact with the a stone surface tends to produce gypsum by a chemical reaction. This allows dirt and soot to bond to stone surfaces, causing staining. In open areas, normal rainwater may wash away the staining; however, in sheltered areas with limited access to fresh water, an impermeable skin can form from the acid rain and result in cavitation of stone material.

	Acid rain can cause corrosion staining to run off lead. Lead materials such as flashing, may well be joining a stone wall and the run off can stain the stone.		Acid rain can cause corrosion staining to run off lead. Lead materials such as flashing, may well be joining a stone wall and the run off can stain the stone.

−	Limestone sills are typically vulnerable to acid rain. Acid rain chemically reacts with the calcium carbonate present in limestone, causing run-off white staining from lime salts. Crystallisation of the lime salts may contribute to further decay. Lime run-off stains can be cleaned immediately with water and brushing. However, if left to carbonate, ~~then~~ rectification becomes more difficult and a more abrasive tactic using chemical agents may be required.	+	Limestone sills are typically vulnerable to acid rain. Acid rain chemically reacts with the calcium carbonate present in limestone, causing run-off white staining from lime salts. Crystallisation of the lime salts may contribute to further decay. Lime run-off stains can be cleaned immediately with water and brushing. However, if left to carbonate,rectification becomes more difficult and a more abrasive tactic using chemical agents may be required.

	Air abrasive techniques are a common physical method along with wet techniques such as washing, steaming and brushing. In addition to physical methods, it might be wise to consider whether chemical techniques would be worthwhile.		Air abrasive techniques are a common physical method along with wet techniques such as washing, steaming and brushing. In addition to physical methods, it might be wise to consider whether chemical techniques would be worthwhile.

−	If the soiling is non-water soluble, then air abrasive techniques can be adopted which include techniques using a variety of machines~~, nozzles may be appropriate~~.	+	If the soiling is non-water soluble, then air abrasive techniques can be adopted which include techniques using a variety of machines.

−	[[File:1111.JPG\|~~RTENOTITLE~~]]~~<br/>~~	+	[[File:1111.JPG\|link=File:1111.JPG]]

−	== ~~'''~~Iron staining to stone~~'''~~ ==	+	== Iron staining to stone ==

	Cast iron typically requires treating every 3-5 years to prevent rusting/decay. Failure to do so will compromise the functionality via corrosion. Not only will rust stain adjoining stone, but the functionality of the original iron material will be compromised. In coastal areas with higher atmospheric salt content, corrosion will be accelerated. Precautions for additional maintenance would be appropriate.		Cast iron typically requires treating every 3-5 years to prevent rusting/decay. Failure to do so will compromise the functionality via corrosion. Not only will rust stain adjoining stone, but the functionality of the original iron material will be compromised. In coastal areas with higher atmospheric salt content, corrosion will be accelerated. Precautions for additional maintenance would be appropriate.
Line 37:		Line 43:
	Metal embedded in structure derived from masonry or mortar can also produce iron staining. It can usually be cleaned mechanically unless the staining is well bedded and the material is particularly strong.		Metal embedded in structure derived from masonry or mortar can also produce iron staining. It can usually be cleaned mechanically unless the staining is well bedded and the material is particularly strong.

−	[[File:3333.jpg\|~~RTENOTITLE~~]]~~<br/>~~	+	[[File:3333.jpg\|link=File:3333.jpg]]

−	== ~~'''~~Salt crystallisation ~~'''~~ ==	+	== Salt crystallisation ==

	Salts are found naturally in the atmosphere and within chemical compositions of materials. External salts can accumulate or deposit on surface materials, while internal salts can leech out via efflorescence.		Salts are found naturally in the atmosphere and within chemical compositions of materials. External salts can accumulate or deposit on surface materials, while internal salts can leech out via efflorescence.
Line 49:		Line 55:
	Salt is water soluble and can generally be cleaned using abrasive water techniques. Many try and rectify salt crystallization by painting masonry which is not advisable as moisture and salt locked in could cause an increase in internal pressure, resulting in spalling.		Salt is water soluble and can generally be cleaned using abrasive water techniques. Many try and rectify salt crystallization by painting masonry which is not advisable as moisture and salt locked in could cause an increase in internal pressure, resulting in spalling.

−	== ~~'''~~Organic biological growths~~'''~~ ==	+	== Organic biological growths ==

	Organic growth, such as the growth of moss, lichen, and algae tend to affect the transpiration rate of materials (they absorb rainwater, preventing drainage). This presence of organic growth offers a moist bed which may promote the growth of damaging creeper plants (such as ivy). Ivy has been known to cause cracks in masonry and mortar. This is especially damaging in cold weather as the cracks filled with moisture may freeze and the expansion during the freezing process can cause further cracking and/or spalling of masonry.		Organic growth, such as the growth of moss, lichen, and algae tend to affect the transpiration rate of materials (they absorb rainwater, preventing drainage). This presence of organic growth offers a moist bed which may promote the growth of damaging creeper plants (such as ivy). Ivy has been known to cause cracks in masonry and mortar. This is especially damaging in cold weather as the cracks filled with moisture may freeze and the expansion during the freezing process can cause further cracking and/or spalling of masonry.

−	[[File:2222.jpg\|~~RTENOTITLE~~]]~~<br/>~~	+	[[File:2222.jpg\|link=File:2222.jpg]]

	The presence of moss may be especially damaging to tiled roofs where moss facilitates moisture ingress into the timber batons causing premature decay. Moss may also fall, or spread into gutters which can lead to them overflowing. Mosses are known to secrete acids, which can etch into some stones causing decay.		The presence of moss may be especially damaging to tiled roofs where moss facilitates moisture ingress into the timber batons causing premature decay. Moss may also fall, or spread into gutters which can lead to them overflowing. Mosses are known to secrete acids, which can etch into some stones causing decay.
Line 59:		Line 65:
	Maintenance will limit and prevent further organic growths. Using sealants on clay tiled, or any tiles roofs for that matter would be discouraged. If biological growth is present, then it should first be determined whether the it actually presents risk to the building’s integrity prior to treatment as the rectification process may prove more damaging than the original growth.		Maintenance will limit and prevent further organic growths. Using sealants on clay tiled, or any tiles roofs for that matter would be discouraged. If biological growth is present, then it should first be determined whether the it actually presents risk to the building’s integrity prior to treatment as the rectification process may prove more damaging than the original growth.

−	= ~~'''~~Conclusion ~~'''~~ =	+	= Conclusion =

	Before remedial works are to be considered, the opinion of a professional surveyor or masonry specialist ought to be sought. It should be ascertained whether the presence of the staining etc. is damaging enough to warrant remedy as invasive remedial work can itself be damaging.		Before remedial works are to be considered, the opinion of a professional surveyor or masonry specialist ought to be sought. It should be ascertained whether the presence of the staining etc. is damaging enough to warrant remedy as invasive remedial work can itself be damaging.
Line 68:		Line 74:

	=== Related articles on Designing Buildings Wiki ===		=== Related articles on Designing Buildings Wiki ===
−	*Damp.
−	*Defects in brickwork.
−	*Defects in dot and dab.
−	*Defects in stonework.
−	*Interstitial condensation.
−	*Mould growth.
−	*Penetrating damp.
−	*Rising damp.
−	*Settlement.
−	*Solid wall insulation.
−	*Wall tie failure.

−	[[Category:Client_procedures]]	+	* Damp.
−	[[Category:Design]]	+	* Defects in brickwork.
−	[[Category:Procurement]]	+	* Defects in dot and dab.
−	[[Category:Products_/_components]]	+	* Defects in stonework.
		+	* Interstitial condensation.
		+	* Mould growth.
		+	* Penetrating damp.
		+	* Rising damp.
		+	* Settlement.
		+	* Solid wall insulation.
		+	* Wall tie failure.
		+
		+	[[Category:Client_procedures]] [[Category:Design]] [[Category:Procurement]] [[Category:Products_/_components]]

← Older revision		Revision as of 11:23, 4 December 2015
Line 3:		Line 3:
	Stone is a tremendous material used in the construction of many period properties. With time, stonework weathers which arguably contributes to the overall character and appeal. Although naturally resistant, stone and other materials typically used in construction must be adequately maintained.		Stone is a tremendous material used in the construction of many period properties. With time, stonework weathers which arguably contributes to the overall character and appeal. Although naturally resistant, stone and other materials typically used in construction must be adequately maintained.

−	Worryingly, the likes of sandblasting, chemical treatments, sealants and repointing with inappropriate materials are becoming increasingly common. Many are inappropriately sold by inexperienced tradesmen and the long-term effects ~~canbe~~ damaging. Caution should be exercised and a professional opinion ought to be sought by anyone looking at cleaning stone or associated materials.	+	Worryingly, the likes of sandblasting, chemical treatments, sealants and repointing with inappropriate materials are becoming increasingly common. Many are inappropriately sold by inexperienced tradesmen and the long-term effects can be damaging. Caution should be exercised and a professional opinion ought to be sought by anyone looking at cleaning stone or associated materials.

	= An overview of pattern staining and soiling =		= An overview of pattern staining and soiling =

−	Pattern staining ~~occurswhen~~ a foreign composite settles or emerges on the internal or ~~externalsurface~~ of a material.	+	Pattern staining occurs when a foreign composite settles or emerges on the internal or external surface of a material.

	There are various causes of pattern staining, such as pollution deposition, salt expulsion, staining from other materials, and so on. Algae soiling is a random growth on buildings that is caused by organic biological deposition on surfaces, such as moss and lichens.		There are various causes of pattern staining, such as pollution deposition, salt expulsion, staining from other materials, and so on. Algae soiling is a random growth on buildings that is caused by organic biological deposition on surfaces, such as moss and lichens.
Line 17:		Line 17:
	== Rainwater ==		== Rainwater ==

−	Typical materials used in the construction of period buildings, such as; limestone, flint, timber, lead, cast iron, and clay are able to withstand rainfall by either being impermeable or having a natural absorption / expulsion process. These processes depend on adequate exposure to the sun and good ventilation. However, too much rainwater,such as ~~fromoverflowing guttersor downpipes~~,can exhaust the material’s adaptive processes. Accordingly, masonry areas that are poorly ventilated, lack sunlight, or become oversaturated from rainwater can darken and stain. Stains develop deeper in materials the longer they remain oversaturated becoming more difficult to eradicate. Surrounding mortar will begin to lose strength and be more easily washed away, thus compromising structural integrity.	+	Typical materials used in the construction of period buildings, such as; limestone, flint, timber, lead, cast iron, and clay are able to withstand rainfall by either being impermeable or having a natural absorption / expulsion process. These processes depend on adequate exposure to the sun and good ventilation. However, too much rainwater,such as from overflowing gutters or down pipes,can exhaust the material’s adaptive processes. Accordingly, masonry areas that are poorly ventilated, lack sunlight, or become oversaturated from rainwater can darken and stain. Stains develop deeper in materials the longer they remain oversaturated becoming more difficult to eradicate. Surrounding mortar will begin to lose strength and be more easily washed away, thus compromising structural integrity.

	Clay tiles are a common foundation for the growth of moss. Moss can be cleaned away from the surface but it would advisable to avoid using sealants that many tradesmen will promote. The types of sealants typically used may trap in moisture and seal in unwanted foreign particles that have not been adequately cleaned away. Building materials should be able to breathe,allowing moisture absorption and subsequent evaporation.		Clay tiles are a common foundation for the growth of moss. Moss can be cleaned away from the surface but it would advisable to avoid using sealants that many tradesmen will promote. The types of sealants typically used may trap in moisture and seal in unwanted foreign particles that have not been adequately cleaned away. Building materials should be able to breathe,allowing moisture absorption and subsequent evaporation.
Line 23:		Line 23:
	== Pollution and acid rain ==		== Pollution and acid rain ==

−	Soot and dirt in the atmosphere from chimneys, motor vehicles etc, can settle on masonry. Certain ~~pollutions~~ (such as bird droppings, mineral, or vegetable deposits) can contain acidic components or soluble salts, which can deposit directly on stone causing staining and /or erosion. Pollution may mix with rainwater in the atmosphere creating acid rain. Acid rain coming into contact with the a stone surface tends to produce gypsum by a chemical reaction. This allows dirt and soot to bond to stone surfaces, causing staining. In open areas, normal rainwater may wash away the staining; however, in sheltered areas with limited access to fresh water, an impermeable skin can form from the acid rain and result in cavitation of stone material.	+	Soot and dirt in the atmosphere from chimneys, motor vehicles etc, can settle on masonry. Certain pollutants (such as bird droppings, mineral, or vegetable deposits) can contain acidic components or soluble salts, which can deposit directly on stone causing staining and /or erosion. Pollution may mix with rainwater in the atmosphere creating acid rain. Acid rain coming into contact with the a stone surface tends to produce gypsum by a chemical reaction. This allows dirt and soot to bond to stone surfaces, causing staining. In open areas, normal rainwater may wash away the staining; however, in sheltered areas with limited access to fresh water, an impermeable skin can form from the acid rain and result in cavitation of stone material.

	Acid rain can cause corrosion staining to run off lead. Lead materials such as flashing, may well be joining a stone wall and the run off can stain the stone.		Acid rain can cause corrosion staining to run off lead. Lead materials such as flashing, may well be joining a stone wall and the run off can stain the stone.
Line 37:		Line 37:
	== Iron staining to stone ==		== Iron staining to stone ==

−	Cast iron typically requires treating every 3-5 years to prevent rusting ~~anddecay~~. Failure to do so will compromise ~~itsfunctionality~~ via corrosion. Not only will rust stain adjoining stone, but the functionality of the original iron material will be compromised. In coastal areas with higher atmospheric salt content, corrosion will be accelerated. Precautions for additional maintenance would be appropriate.	+	Cast iron typically requires treating every 3-5 years to prevent rusting and decay. Failure to do so will compromise its functionality via corrosion. Not only will rust stain adjoining stone, but the functionality of the original iron material will be compromised. In coastal areas with higher atmospheric salt content, corrosion will be accelerated. Precautions for additional maintenance would be appropriate.

−	Routine weather proofing and maintenance should avoid failure. Filters could be added to the top of drainpipes to minimise build-up of debris in the gutters and prevent subsequent water stagnation and rusting of pipes. Where pipes have broken or there ~~isextensive~~ decay, replacement might be required.	+	Routine weather proofing and maintenance should avoid failure. Filters could be added to the top of drainpipes to minimise build-up of debris in the gutters and prevent subsequent water stagnation and rusting of pipes. Where pipes have broken or there is extensive decay, replacement might be required.

−	Metal embedded in structure derived from masonry or mortar can also produce iron staining. ~~Thiscan~~ usually be cleaned mechanically unless the staining is well bedded and the material is particularly strong.	+	Metal embedded in structure derived from masonry or mortar can also produce iron staining. This can usually be cleaned mechanically unless the staining is well bedded and the material is particularly strong.

	[[File:3333.jpg\|link=File:3333.jpg]]		[[File:3333.jpg\|link=File:3333.jpg]]
Line 47:		Line 47:
	== Salt crystallisation ==		== Salt crystallisation ==

−	Salts are found naturally in the atmosphere and within the chemical ~~compositionof~~ materials. External salts can accumulate or deposit on surface materials, while internal salts can leech out via efflorescence.	+	Salts are found naturally in the atmosphere and within the chemical composition of materials. External salts can accumulate or deposit on surface materials, while internal salts can leech out via efflorescence.

	Efflorescence takes place when salts escape a porous material when drying gradually. Typically the appearance will be a powdery residue on the surface. Rates of evaporation can influence the appearance and distribution of salt in materials, often noticeable by white curves. It is important to note that excessive salt crystallisation within pores exerts internal pressures on materials. This could result in subsequent damage such as cryptofluorescence.		Efflorescence takes place when salts escape a porous material when drying gradually. Typically the appearance will be a powdery residue on the surface. Rates of evaporation can influence the appearance and distribution of salt in materials, often noticeable by white curves. It is important to note that excessive salt crystallisation within pores exerts internal pressures on materials. This could result in subsequent damage such as cryptofluorescence.
Line 53:		Line 53:
	Salts could be absorbed into the porous material from the atmosphere, or from another material used in the fabric of the building such as the mortar. If the stained wall is close to a road, then salts could be splashed and deposit on the wall’s surface.		Salts could be absorbed into the porous material from the atmosphere, or from another material used in the fabric of the building such as the mortar. If the stained wall is close to a road, then salts could be splashed and deposit on the wall’s surface.

−	Salt is water soluble and can generally be cleaned using abrasive water techniques. Many try ~~torectify~~ salt crystallization by painting masonry which is not advisable as moisture and salt locked in could cause an increase in internal pressure, resulting in spalling.	+	Salt is water soluble and can generally be cleaned using abrasive water techniques. Many try to rectify salt crystallization by painting masonry which is not advisable as moisture and salt locked in could cause an increase in internal pressure, resulting in spalling.

	== Organic biological growths ==		== Organic biological growths ==

← Older revision		Revision as of 11:21, 4 December 2015
Line 17:		Line 17:
	== Rainwater ==		== Rainwater ==

−	Typical materials used in the construction of period buildings, such as; limestone, flint, timber, lead, cast iron, and clay are able to withstand rainfall by either being impermeable or having a natural absorption / expulsion process. These processes depend on adequate exposure to the sun and good ventilation. However, too much rainwater,such as fromoverflowing ~~guttersordownpipes~~,can exhaust the material’s adaptive processes. Accordingly, masonry areas that are poorly ventilated, lack sunlight, or become oversaturated from rainwater can darken and stain. Stains develop deeper in materials the longer they remain oversaturated becoming more difficult to eradicate. Surrounding mortar will begin to lose strength and be more easily washed away, thus compromising structural integrity.	+	Typical materials used in the construction of period buildings, such as; limestone, flint, timber, lead, cast iron, and clay are able to withstand rainfall by either being impermeable or having a natural absorption / expulsion process. These processes depend on adequate exposure to the sun and good ventilation. However, too much rainwater,such as fromoverflowing guttersor downpipes,can exhaust the material’s adaptive processes. Accordingly, masonry areas that are poorly ventilated, lack sunlight, or become oversaturated from rainwater can darken and stain. Stains develop deeper in materials the longer they remain oversaturated becoming more difficult to eradicate. Surrounding mortar will begin to lose strength and be more easily washed away, thus compromising structural integrity.

	Clay tiles are a common foundation for the growth of moss. Moss can be cleaned away from the surface but it would advisable to avoid using sealants that many tradesmen will promote. The types of sealants typically used may trap in moisture and seal in unwanted foreign particles that have not been adequately cleaned away. Building materials should be able to breathe,allowing moisture absorption and subsequent evaporation.		Clay tiles are a common foundation for the growth of moss. Moss can be cleaned away from the surface but it would advisable to avoid using sealants that many tradesmen will promote. The types of sealants typically used may trap in moisture and seal in unwanted foreign particles that have not been adequately cleaned away. Building materials should be able to breathe,allowing moisture absorption and subsequent evaporation.
Line 37:		Line 37:
	== Iron staining to stone ==		== Iron staining to stone ==

−	Cast iron typically requires treating every 3-5 years to prevent rusting~~/decay~~. Failure to do so will compromise ~~the functionality~~ via corrosion. Not only will rust stain adjoining stone, but the functionality of the original iron material will be compromised. In coastal areas with higher atmospheric salt content, corrosion will be accelerated. Precautions for additional maintenance would be appropriate.	+	Cast iron typically requires treating every 3-5 years to prevent rusting anddecay. Failure to do so will compromise itsfunctionality via corrosion. Not only will rust stain adjoining stone, but the functionality of the original iron material will be compromised. In coastal areas with higher atmospheric salt content, corrosion will be accelerated. Precautions for additional maintenance would be appropriate.

−	Routine weather proofing and maintenance should avoid failure. Filters could be added to the top of drainpipes to ~~minimize~~ build-up of debris in the gutters and prevent subsequent water stagnation and rusting of pipes. Where pipes have broken or ~~extensive~~ decay, replacement might be required.	+	Routine weather proofing and maintenance should avoid failure. Filters could be added to the top of drainpipes to minimise build-up of debris in the gutters and prevent subsequent water stagnation and rusting of pipes. Where pipes have broken or there isextensive decay, replacement might be required.

−	Metal embedded in structure derived from masonry or mortar can also produce iron staining. ~~It can~~ usually be cleaned mechanically unless the staining is well bedded and the material is particularly strong.	+	Metal embedded in structure derived from masonry or mortar can also produce iron staining. Thiscan usually be cleaned mechanically unless the staining is well bedded and the material is particularly strong.

	[[File:3333.jpg\|link=File:3333.jpg]]		[[File:3333.jpg\|link=File:3333.jpg]]
Line 47:		Line 47:
	== Salt crystallisation ==		== Salt crystallisation ==

−	Salts are found naturally in the atmosphere and within chemical ~~compositions of~~ materials. External salts can accumulate or deposit on surface materials, while internal salts can leech out via efflorescence.	+	Salts are found naturally in the atmosphere and within the chemical compositionof materials. External salts can accumulate or deposit on surface materials, while internal salts can leech out via efflorescence.

	Efflorescence takes place when salts escape a porous material when drying gradually. Typically the appearance will be a powdery residue on the surface. Rates of evaporation can influence the appearance and distribution of salt in materials, often noticeable by white curves. It is important to note that excessive salt crystallisation within pores exerts internal pressures on materials. This could result in subsequent damage such as cryptofluorescence.		Efflorescence takes place when salts escape a porous material when drying gradually. Typically the appearance will be a powdery residue on the surface. Rates of evaporation can influence the appearance and distribution of salt in materials, often noticeable by white curves. It is important to note that excessive salt crystallisation within pores exerts internal pressures on materials. This could result in subsequent damage such as cryptofluorescence.

−	Salts could be absorbed into the porous material from the atmosphere, or from another material used in the fabric of the building such as the mortar. If the ~~subject~~ stained wall is close to a road, then salts could be splashed and deposit on the wall’s surface.	+	Salts could be absorbed into the porous material from the atmosphere, or from another material used in the fabric of the building such as the mortar. If the stained wall is close to a road, then salts could be splashed and deposit on the wall’s surface.

−	Salt is water soluble and can generally be cleaned using abrasive water techniques. Many try ~~and rectify~~ salt crystallization by painting masonry which is not advisable as moisture and salt locked in could cause an increase in internal pressure, resulting in spalling.	+	Salt is water soluble and can generally be cleaned using abrasive water techniques. Many try torectify salt crystallization by painting masonry which is not advisable as moisture and salt locked in could cause an increase in internal pressure, resulting in spalling.

	== Organic biological growths ==		== Organic biological growths ==

−	Organic growth, such as the growth of moss, lichen, and algae tend to affect the transpiration rate of materials (they absorb rainwater, preventing drainage). This presence of organic growth offers a moist bed which may promote the growth of damaging creeper plants (such as ivy). Ivy has been known to cause cracks in masonry and mortar. This is especially damaging in cold weather as the cracks filled with moisture may freeze and the expansion during the freezing process can cause further cracking and/or spalling ~~of masonry~~.	+	Organic growth, such as the growth of moss, lichen, and algae tend to affect the transpiration rate of materials (they absorb rainwater, preventing drainage). This presence of organic growth offers a moist bed which may promote the growth of damaging creeper plants (such as ivy). Ivy has been known to cause cracks in masonry and mortar. This is especially damaging in cold weather as the cracks filled with moisture may freeze and the expansion during the freezing process can cause further cracking and / or spalling.

	[[File:2222.jpg\|link=File:2222.jpg]]		[[File:2222.jpg\|link=File:2222.jpg]]

−	The presence of moss may be especially damaging to tiled roofs where moss facilitates moisture ingress into ~~the~~ timber batons causing premature decay. Moss may also fall, or spread into gutters which can lead to them overflowing. Mosses are known to secrete acids, which can etch into some stones causing decay.	+	The presence of moss may be especially damaging to tiled roofs where moss facilitates moisture ingress into timber batons causing premature decay. Moss may also fall, or spread into gutters which can lead to them overflowing. Mosses are known to secrete acids, which can etch into some stones causing decay.

−	Maintenance will limit and prevent further organic ~~growths~~. Using sealants on clay tiled, or any tiles roofs ~~for that matter would~~ be discouraged. If biological growth is present, then it should first be determined ~~whether the it~~ actually presents risk to the building’s integrity prior to treatment as the rectification process may prove more damaging than the original growth.	+	Maintenance will limit and prevent further organic growth. Using sealants on clay tiled, or any tiles roofs should be discouraged. If biological growth is present, then it should first be determined whetherit actually presents a risk to the building’s integrity prior to treatment as the rectification process may prove more damaging than the original growth.

	= Conclusion =		= Conclusion =

−	Before remedial works are to be considered, the opinion of a professional surveyor or masonry specialist ought to be sought. It should be ascertained whether the presence of ~~the~~ staining ~~etc.~~ is damaging enough to warrant remedy as invasive remedial work can itself be damaging.	+	Before remedial works are to be considered, the opinion of a professional surveyor or masonry specialist ought to be sought. It should be ascertained whether the presence of staining is damaging enough to warrant remedy as invasive remedial work can itself be damaging.

	Prevention measures (such as sealants) are not always ideal and can be more damaging in the long-term. Staining and weathering to masonry can add to the aesthetic appeal of a building but careful consideration should be exercised in assessing whether that appeal is at the expense of structural integrity.		Prevention measures (such as sealants) are not always ideal and can be more damaging in the long-term. Staining and weathering to masonry can add to the aesthetic appeal of a building but careful consideration should be exercised in assessing whether that appeal is at the expense of structural integrity.