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October 20
防水材料概述
防水材料由特殊有机高分子乳液，无机专用粉料和水调配而成的。其中添加了具有防腐性能的添加剂。聚合物防水材料是集防水，抗渗，防潮，防腐为一体的双组份防水材料。建筑物需要进行防水处理的部位主要是屋面、墙面、地面和地下室。
墙体材料的种类
墙体材料主要包括砖、板、块三大类材料。
在目前的砌筑建筑中砖型墙体材料的使用量最广泛、最多。砖型墙体材料的种类主要有实心粘土砖、粘土空心砖、粘土多孔砖、粘土粉煤灰砖、煤矸石多孔砖、水泥沙石多孔砖和各种路面砖等。
板型墙体材料的种类主要有：石膏空心条板、镀锌钢丝网复合轻质夹心板、金属面聚苯乙烯夹芯板、钢丝网架水泥聚苯夹芯板、工业废渣混凝土空心隔墙条板、秸杆镁质水泥轻质隔墙条板等。
砌块型墙体材料的种类有：加气混凝土砌块、轻集料混凝土小型空心砌块、混凝土小型空心砌块、石膏空心砌块、粉煤灰空心砌块等。
保温材料的概念
保温材料一般是指导热系数小于等于0.3的材料。
在建筑和工业中采用良好的保温技术与材料，往往能起到事半功倍的效果。统计表明，建筑中每使用一吨矿物棉绝热制品，一年可节约一吨石油。北京安苑北里节能小区采用情况表明，单位面积节煤率每年为11.91公斤标煤／平方米。工业设备与管道的保温，采用良好的绝热措施与材料，可显著降低生产能耗和成本，改善环境，同时有较好的经济效益。如：工业设备和管道工程中，良好的保温条件，可使热量损失降低95％左右，通常用于保温材料的投资一年左右可以通过节约的能量收回。
Links: breathable membrane, roofing membrane, roofing foil, membrane, 材料, 防水透气膜 防水材料 保温材料 墙体材料 防水透汽膜 fiberglass mesh, 律师, Links, valve, Google排名 September 17 山泉建筑材料特性及功能：
A、 山泉防水材料具有良好的防水性能，有效阻隔风雨对室内的侵袭
B、提高居住舒适性
防水透汽膜被称为能呼吸的膜(membrane)，具有极佳的透汽性能，使水汽能够迅速排
出，降低室内潮湿度，有效避免霉菌和冷凝的形成，从而极大的改善了居
住环境的舒适性，并提高建筑物的耐久性。
C、 山泉保温材料节能保温
通过有效阻档冷热空气的侵入，起到节能保温功能。与其它保温材料配套
使用，可以有效阻挡水汽渗入保温层，对保温层形成全面保护，同时由于
室内外温差造成的结露现象，也可以通过防水透气膜良好的透汽功能，使
水汽迅速排出，从而确保保温层的功效，达到持续节能的作用，
D、 山泉墙体材料抗撕裂，耐磨，低温柔性好。
E、具有极好的抗紫外线、耐老化特点，夏季室外曝晒三个月，仍
保持良好的产品性能，产品经久耐用。
F、产品材料为改性聚烯烃膜和增强无纺布，符合国际环保要求。
G、产品柔软、轻薄，易于施工，不易留下施工死角。
引用
Membrane products
防水透汽膜或许在国内还比较陌生，但在欧美，该产品的生产及应用已非常成熟。但要生产高品质的防水透汽膜一直以来为欧美巨头所垄断，要设计与研发防水透汽膜生产线技术含量极高，而且生产工艺极难掌握，同时该产品要通过CE机构为时半年多的各项严格的检测，方可在市场上销售，可以说又设置了一道技术壁垒。因此防水透汽膜的生产与销售多年来在同内无人问津。
宁波山泉建材有限公司，其母公司为宁波山泉玻纤有限公司，是国内最大的玻纤网布生产商及出口商，凭借母公司雄厚的资金实力与坚实的技术研发队伍，同时凭借公司总经理叶泉友超人的胆识，在2005年毅然决定研发与生产防水透汽膜。在过去的2年多时间，可以说困难重重，我们几度陷入困境，几度想放弃，但最终，凭借着山泉人坚韧不拔及永不服输的精神，在公司总经理叶泉友的带领下，攻克重重困难。终于在2007年底成功研发出防水透汽膜生产线，同时掌握了所有生产工艺，并根据CE检测要求，建议了完善的实验及测试中心。从此结束了只有欧美巨头才能生产高品质防水透汽膜的历史，成为国内第一个吃螃蟹的人。
2008年2月，宁波山泉建材第一批防水透汽膜共计10个柜漂洋过海；2008年4月，产品经历为时8个多月的检测，一次性通过CE权威检测机构的各项检测；2008年6月，宁波山泉建材有限公司参加了在上海举办的第六届中国国际屋面和建筑防水技术展览会，引起的广大专业人士极大的兴趣与观注；同时公司产品已报国家发明专利及2008年国家重点新产品计划项目。
回顾过去，是一条充满艰辛与困惑的路，展望未来，宁波山泉建材有限公司定能在广阔的国内、国际舞台上成为一颗崔灿的明星。
引用
Membrane products
-
Membrane products: laminated by one layer of modified polyolefin membrane and two layers of reinforced non woven.
-
-
Function of the membrane
A: The breathable membrane effectively prevent the construction from rain and wind.
B: The roofing membrane can strengthen the circulation of water vapour, reduce the humidity, improve the living environment.
C: the roofing foil effectively avoid the effect from the cold and hot air, had the thermal insulation property, effect can be heightened in case installed together with the other materials.
D: the membrane is Anti-ultraviolet:
-
Membrane Application
The membrane has the extensive application in the field where requests water resistance and vapour permeable, e.g., construction, means of transport, etc., which is an ideal functional material.
-
June 05
-
Membrane products: laminated by one layer of modified polyolefin membrane and two layers of reinforced non woven.
-
-
Function of the membrane
A: The breathable membrane effectively prevent the construction from rain and wind.
B: The roofing membrane can strengthen the circulation of water vapour, reduce the humidity, improve the living environment.
C: the roofing foil effectively avoid the effect from the cold and hot air, had the thermal insulation property, effect can be heightened in case installed together with the other materials.
D: the membrane is Anti-ultraviolet:
-
Membrane Application
The membrane has the extensive application in the field where requests water resistance and vapour permeable, e.g., construction, means of transport, etc., which is an ideal functional material.
-
Membrane Technical data
Mass per unit area EN1849 g/m2 100g (?0%) 120g (?0%) Length
EN1848 m 50 50 Width EN1848 m 1.5(-0.5%,+1.5% 1.5(-0.5%,+1.5%
Reaction to fire EN13501-1:2002 EN11925-2
引用
How widely are they used and in what applications ?
How widely are they used and in what applications ?
A2 Breather membranes have been used abroad in construction since the 1970’s.
Membranes were first Certified by the BBA in 1982 as sheathing membranes for timber frame
walls and as roof tile underlays in conventionally ventilated cold roofs. They were
subsequently approved as roof tile underlays in warm roof constructions in 1982 and most
recently in cold non ventilated roof constructions in 1999. At the time of writing this article,
Certificates for roof tile underlays used as part of a cold unventilated pitched roof system in
dwellings have been issued as shown in Table 1
Table 1 – BBA Certificates issued for cold unventilated roof applications (at 15.03.04)
Certificate No. Product name Certificate holder
99/3648 Daltex Roofshield Don & Low Ltd Nonwovens
00/3749 Permo Forte Klober Ltd
01/3842 Global Breather Roof Tile
Underlay
EBC UK Ltd
03/4017 Breathline Vapour permeable
Underlay
Knauf Insulation Ltd
03/4062 Monarperm 700 Icopal Ltd
04/4078 - DS3 VapR-free underlay Mercury Building products Ltd
04/4101 Tyvek Universal Underlays DuPont de Nemours (Luxembourg) Sarl
Details of approved products can be found on www.bbacerts.co.uk or by phoning the BBA
hotline on 01923 665400. Users are advised to check the validity of Certificates and any
limitations on the scope of the approval.
Q3 Can they be used simply ‘instead’ of conventional eaves ventilation ?
A3 Only if a number of measures are taken to limit the ingress of water vapour into the
unventilated space. In this regard, the roof system must be considered as a whole from ceiling
to roof tiles, including the following design points:
- all penetrations into the roof space must be properly sealed
- loft hatches must incorporate effective compressible draught seals
- the rooms below the ceiling must include provision for the dispersal and rapid dilution of
water vapour in accordance with the Building Regulations, including extractor fans in
rooms that may experience high humidity
- All water tanks in the loft space must be covered
- Any vent pipes should be arranged so that they do not discharge water vapour into the loft
space
See also Q&A10 to 15 and the relevant BBA Certificate for conditions of approval.
Q4 What are the advantages of using the unventilated system ?
A4 One of the main advantages is reducing the amount of heat lost by air leakage through the
ceiling and from the loft space to the outside. Up to 25% of the heat lost through a
conventional roof system is by this mechanism. The unventilated roof ‘system’ will reduce
this mechanism of heat loss, more so if the underlay laps are sealed.
In addition, not having to provide eaves and ridge ventilation can help to save time and cost
on site and can give a more desirable appearance to the finished roof.
Q5 What are the disadvantages of using the system ?
A5 Extra time and care is needed to ensure that penetrations into the ceiling are properly sealed
and that the loft space is protected from sources of water vapour, in accordance with the
requirements of the Certificate. See also A3.
If the ceiling is constructed without due attention to sealing joints and around penetrations, the
opportunity for moisture ingress into the loft space and consequent risk of condensation
occurring is increased. This is also true of conventionally ventilated constructions where the
effect of wind movement over the roof can reduce the air pressure in the loft space and ‘suck’
moisture laden warm air from the living space into the loft space. However it is recognised
that the rate of moisture removal via the ventilated and unventilated approach is not the same.
It is therefore important that the ceiling is sealed to an appropriate level. BBA computer
modelling of the behaviour of roofs has assumed effective ceiling ‘defect’ areas of up to 10
square mm per square metre of ceiling. See also Q/A 6, 7 and 11.
There are reports concerning ‘flapping-noise’ in roofs incorporating some types of permeable
roof tile underlay membranes in certain wind conditions. The BBA has, however, only
received a very limited number of reports in this regard and therefore do not view it as a
fundamental problem.
Awarenessnetworks GlassBuy IeTrade P1 P2 P3 Lead LiveSpace Blonder Meebq Maverick Bruce
Zegna Nings Cilo 385857762 SoulCast SpotsDir DreamHome EcTrade MySpace Exportnation
PerfectCondoz Myekoo Efreedir Fukesi CleverDir blogtext Ca-Yahoo Uk-Yahoo Uk-Yahoo-Po Au-Yahoo
引用
How widely are they used and in what applications ?
How widely are they used and in what applications ?
A2 Breather membranes have been used abroad in construction since the 1970’s.
Membranes were first Certified by the BBA in 1982 as sheathing membranes for timber frame
walls and as roof tile underlays in conventionally ventilated cold roofs. They were
subsequently approved as roof tile underlays in warm roof constructions in 1982 and most
recently in cold non ventilated roof constructions in 1999. At the time of writing this article,
Certificates for roof tile underlays used as part of a cold unventilated pitched roof system in
dwellings have been issued as shown in Table 1
Table 1 – BBA Certificates issued for cold unventilated roof applications (at 15.03.04)
Certificate No. Product name Certificate holder
99/3648 Daltex Roofshield Don & Low Ltd Nonwovens
00/3749 Permo Forte Klober Ltd
01/3842 Global Breather Roof Tile
Underlay
EBC UK Ltd
03/4017 Breathline Vapour permeable
Underlay
Knauf Insulation Ltd
03/4062 Monarperm 700 Icopal Ltd
04/4078 - DS3 VapR-free underlay Mercury Building products Ltd
04/4101 Tyvek Universal Underlays DuPont de Nemours (Luxembourg) Sarl
Details of approved products can be found on www.bbacerts.co.uk or by phoning the BBA
hotline on 01923 665400. Users are advised to check the validity of Certificates and any
limitations on the scope of the approval.
Q3 Can they be used simply ‘instead’ of conventional eaves ventilation ?
A3 Only if a number of measures are taken to limit the ingress of water vapour into the
unventilated space. In this regard, the roof system must be considered as a whole from ceiling
to roof tiles, including the following design points:
- all penetrations into the roof space must be properly sealed
- loft hatches must incorporate effective compressible draught seals
- the rooms below the ceiling must include provision for the dispersal and rapid dilution of
water vapour in accordance with the Building Regulations, including extractor fans in
rooms that may experience high humidity
- All water tanks in the loft space must be covered
- Any vent pipes should be arranged so that they do not discharge water vapour into the loft
space
See also Q&A10 to 15 and the relevant BBA Certificate for conditions of approval.
Q4 What are the advantages of using the unventilated system ?
A4 One of the main advantages is reducing the amount of heat lost by air leakage through the
ceiling and from the loft space to the outside. Up to 25% of the heat lost through a
conventional roof system is by this mechanism. The unventilated roof ‘system’ will reduce
this mechanism of heat loss, more so if the underlay laps are sealed.
In addition, not having to provide eaves and ridge ventilation can help to save time and cost
on site and can give a more desirable appearance to the finished roof.
Q5 What are the disadvantages of using the system ?
A5 Extra time and care is needed to ensure that penetrations into the ceiling are properly sealed
and that the loft space is protected from sources of water vapour, in accordance with the
requirements of the Certificate. See also A3.
If the ceiling is constructed without due attention to sealing joints and around penetrations, the
opportunity for moisture ingress into the loft space and consequent risk of condensation
occurring is increased. This is also true of conventionally ventilated constructions where the
effect of wind movement over the roof can reduce the air pressure in the loft space and ‘suck’
moisture laden warm air from the living space into the loft space. However it is recognised
that the rate of moisture removal via the ventilated and unventilated approach is not the same.
It is therefore important that the ceiling is sealed to an appropriate level. BBA computer
modelling of the behaviour of roofs has assumed effective ceiling ‘defect’ areas of up to 10
square mm per square metre of ceiling. See also Q/A 6, 7 and 11.
There are reports concerning ‘flapping-noise’ in roofs incorporating some types of permeable
roof tile underlay membranes in certain wind conditions. The BBA has, however, only
received a very limited number of reports in this regard and therefore do not view it as a
fundamental problem.
Awarenessnetworks GlassBuy IeTrade P1 P2 P3 Lead LiveSpace Blonder Meebq Maverick Bruce
Zegna Nings Cilo 385857762 SoulCast SpotsDir DreamHome EcTrade MySpace Exportnation
PerfectCondoz Myekoo Efreedir Fukesi CleverDir blogtext Ca-Yahoo Uk-Yahoo Uk-Yahoo-Po Au-Yahoo
引用
How widely are they used and in what applications ?
How widely are they used and in what applications ?
A2 Breather membranes have been used abroad in construction since the 1970’s.
Membranes were first Certified by the BBA in 1982 as sheathing membranes for timber frame
walls and as roof tile underlays in conventionally ventilated cold roofs. They were
subsequently approved as roof tile underlays in warm roof constructions in 1982 and most
recently in cold non ventilated roof constructions in 1999. At the time of writing this article,
Certificates for roof tile underlays used as part of a cold unventilated pitched roof system in
dwellings have been issued as shown in Table 1
Table 1 – BBA Certificates issued for cold unventilated roof applications (at 15.03.04)
Certificate No. Product name Certificate holder
99/3648 Daltex Roofshield Don & Low Ltd Nonwovens
00/3749 Permo Forte Klober Ltd
01/3842 Global Breather Roof Tile
Underlay
EBC UK Ltd
03/4017 Breathline Vapour permeable
Underlay
Knauf Insulation Ltd
03/4062 Monarperm 700 Icopal Ltd
04/4078 - DS3 VapR-free underlay Mercury Building products Ltd
04/4101 Tyvek Universal Underlays DuPont de Nemours (Luxembourg) Sarl
Details of approved products can be found on www.bbacerts.co.uk or by phoning the BBA
hotline on 01923 665400. Users are advised to check the validity of Certificates and any
limitations on the scope of the approval.
Q3 Can they be used simply ‘instead’ of conventional eaves ventilation ?
A3 Only if a number of measures are taken to limit the ingress of water vapour into the
unventilated space. In this regard, the roof system must be considered as a whole from ceiling
to roof tiles, including the following design points:
- all penetrations into the roof space must be properly sealed
- loft hatches must incorporate effective compressible draught seals
- the rooms below the ceiling must include provision for the dispersal and rapid dilution of
water vapour in accordance with the Building Regulations, including extractor fans in
rooms that may experience high humidity
- All water tanks in the loft space must be covered
- Any vent pipes should be arranged so that they do not discharge water vapour into the loft
space
See also Q&A10 to 15 and the relevant BBA Certificate for conditions of approval.
Q4 What are the advantages of using the unventilated system ?
A4 One of the main advantages is reducing the amount of heat lost by air leakage through the
ceiling and from the loft space to the outside. Up to 25% of the heat lost through a
conventional roof system is by this mechanism. The unventilated roof ‘system’ will reduce
this mechanism of heat loss, more so if the underlay laps are sealed.
In addition, not having to provide eaves and ridge ventilation can help to save time and cost
on site and can give a more desirable appearance to the finished roof.
Q5 What are the disadvantages of using the system ?
A5 Extra time and care is needed to ensure that penetrations into the ceiling are properly sealed
and that the loft space is protected from sources of water vapour, in accordance with the
requirements of the Certificate. See also A3.
If the ceiling is constructed without due attention to sealing joints and around penetrations, the
opportunity for moisture ingress into the loft space and consequent risk of condensation
occurring is increased. This is also true of conventionally ventilated constructions where the
effect of wind movement over the roof can reduce the air pressure in the loft space and ‘suck’
moisture laden warm air from the living space into the loft space. However it is recognised
that the rate of moisture removal via the ventilated and unventilated approach is not the same.
It is therefore important that the ceiling is sealed to an appropriate level. BBA computer
modelling of the behaviour of roofs has assumed effective ceiling ‘defect’ areas of up to 10
square mm per square metre of ceiling. See also Q/A 6, 7 and 11.
There are reports concerning ‘flapping-noise’ in roofs incorporating some types of permeable
roof tile underlay membranes in certain wind conditions. The BBA has, however, only
received a very limited number of reports in this regard and therefore do not view it as a
fundamental problem.
Awarenessnetworks GlassBuy IeTrade P1 P2 P3 Lead LiveSpace Blonder Meebq Maverick Bruce
Zegna Nings Cilo 385857762 SoulCast SpotsDir DreamHome EcTrade MySpace Exportnation
PerfectCondoz Myekoo Efreedir Fukesi CleverDir blogtext Ca-Yahoo Uk-Yahoo Uk-Yahoo-Po Au-Yahoo
引用
How widely are they used and in what applications ?
How widely are they used and in what applications ?
A2 Breather membranes have been used abroad in construction since the 1970’s.
Membranes were first Certified by the BBA in 1982 as sheathing membranes for timber frame
walls and as roof tile underlays in conventionally ventilated cold roofs. They were
subsequently approved as roof tile underlays in warm roof constructions in 1982 and most
recently in cold non ventilated roof constructions in 1999. At the time of writing this article,
Certificates for roof tile underlays used as part of a cold unventilated pitched roof system in
dwellings have been issued as shown in Table 1
Table 1 – BBA Certificates issued for cold unventilated roof applications (at 15.03.04)
Certificate No. Product name Certificate holder
99/3648 Daltex Roofshield Don & Low Ltd Nonwovens
00/3749 Permo Forte Klober Ltd
01/3842 Global Breather Roof Tile
Underlay
EBC UK Ltd
03/4017 Breathline Vapour permeable
Underlay
Knauf Insulation Ltd
03/4062 Monarperm 700 Icopal Ltd
04/4078 - DS3 VapR-free underlay Mercury Building products Ltd
04/4101 Tyvek Universal Underlays DuPont de Nemours (Luxembourg) Sarl
Details of approved products can be found on www.bbacerts.co.uk or by phoning the BBA
hotline on 01923 665400. Users are advised to check the validity of Certificates and any
limitations on the scope of the approval.
Q3 Can they be used simply ‘instead’ of conventional eaves ventilation ?
A3 Only if a number of measures are taken to limit the ingress of water vapour into the
unventilated space. In this regard, the roof system must be considered as a whole from ceiling
to roof tiles, including the following design points:
- all penetrations into the roof space must be properly sealed
- loft hatches must incorporate effective compressible draught seals
- the rooms below the ceiling must include provision for the dispersal and rapid dilution of
water vapour in accordance with the Building Regulations, including extractor fans in
rooms that may experience high humidity
- All water tanks in the loft space must be covered
- Any vent pipes should be arranged so that they do not discharge water vapour into the loft
space
See also Q&A10 to 15 and the relevant BBA Certificate for conditions of approval.
Q4 What are the advantages of using the unventilated system ?
A4 One of the main advantages is reducing the amount of heat lost by air leakage through the
ceiling and from the loft space to the outside. Up to 25% of the heat lost through a
conventional roof system is by this mechanism. The unventilated roof ‘system’ will reduce
this mechanism of heat loss, more so if the underlay laps are sealed.
In addition, not having to provide eaves and ridge ventilation can help to save time and cost
on site and can give a more desirable appearance to the finished roof.
Q5 What are the disadvantages of using the system ?
A5 Extra time and care is needed to ensure that penetrations into the ceiling are properly sealed
and that the loft space is protected from sources of water vapour, in accordance with the
requirements of the Certificate. See also A3.
If the ceiling is constructed without due attention to sealing joints and around penetrations, the
opportunity for moisture ingress into the loft space and consequent risk of condensation
occurring is increased. This is also true of conventionally ventilated constructions where the
effect of wind movement over the roof can reduce the air pressure in the loft space and ‘suck’
moisture laden warm air from the living space into the loft space. However it is recognised
that the rate of moisture removal via the ventilated and unventilated approach is not the same.
It is therefore important that the ceiling is sealed to an appropriate level. BBA computer
modelling of the behaviour of roofs has assumed effective ceiling ‘defect’ areas of up to 10
square mm per square metre of ceiling. See also Q/A 6, 7 and 11.
There are reports concerning ‘flapping-noise’ in roofs incorporating some types of permeable
roof tile underlay membranes in certain wind conditions. The BBA has, however, only
received a very limited number of reports in this regard and therefore do not view it as a
fundamental problem.
Awarenessnetworks GlassBuy IeTrade P1 P2 P3 Lead LiveSpace Blonder Meebq Maverick Bruce
Zegna Nings Cilo 385857762 SoulCast SpotsDir DreamHome EcTrade MySpace Exportnation
PerfectCondoz Myekoo Efreedir Fukesi CleverDir blogtext Ca-Yahoo Uk-Yahoo Uk-Yahoo-Po Au-Yahoo
引用
How widely are they used and in what applications ?
How widely are they used and in what applications ?
A2 Breather membranes have been used abroad in construction since the 1970’s.
Membranes were first Certified by the BBA in 1982 as sheathing membranes for timber frame
walls and as roof tile underlays in conventionally ventilated cold roofs. They were
subsequently approved as roof tile underlays in warm roof constructions in 1982 and most
recently in cold non ventilated roof constructions in 1999. At the time of writing this article,
Certificates for roof tile underlays used as part of a cold unventilated pitched roof system in
dwellings have been issued as shown in Table 1
Table 1 – BBA Certificates issued for cold unventilated roof applications (at 15.03.04)
Certificate No. Product name Certificate holder
99/3648 Daltex Roofshield Don & Low Ltd Nonwovens
00/3749 Permo Forte Klober Ltd
01/3842 Global Breather Roof Tile
Underlay
EBC UK Ltd
03/4017 Breathline Vapour permeable
Underlay
Knauf Insulation Ltd
03/4062 Monarperm 700 Icopal Ltd
04/4078 - DS3 VapR-free underlay Mercury Building products Ltd
04/4101 Tyvek Universal Underlays DuPont de Nemours (Luxembourg) Sarl
Details of approved products can be found on www.bbacerts.co.uk or by phoning the BBA
hotline on 01923 665400. Users are advised to check the validity of Certificates and any
limitations on the scope of the approval.
Q3 Can they be used simply ‘instead’ of conventional eaves ventilation ?
A3 Only if a number of measures are taken to limit the ingress of water vapour into the
unventilated space. In this regard, the roof system must be considered as a whole from ceiling
to roof tiles, including the following design points:
- all penetrations into the roof space must be properly sealed
- loft hatches must incorporate effective compressible draught seals
- the rooms below the ceiling must include provision for the dispersal and rapid dilution of
water vapour in accordance with the Building Regulations, including extractor fans in
rooms that may experience high humidity
- All water tanks in the loft space must be covered
- Any vent pipes should be arranged so that they do not discharge water vapour into the loft
space
See also Q&A10 to 15 and the relevant BBA Certificate for conditions of approval.
Q4 What are the advantages of using the unventilated system ?
A4 One of the main advantages is reducing the amount of heat lost by air leakage through the
ceiling and from the loft space to the outside. Up to 25% of the heat lost through a
conventional roof system is by this mechanism. The unventilated roof ‘system’ will reduce
this mechanism of heat loss, more so if the underlay laps are sealed.
In addition, not having to provide eaves and ridge ventilation can help to save time and cost
on site and can give a more desirable appearance to the finished roof.
Q5 What are the disadvantages of using the system ?
A5 Extra time and care is needed to ensure that penetrations into the ceiling are properly sealed
and that the loft space is protected from sources of water vapour, in accordance with the
requirements of the Certificate. See also A3.
If the ceiling is constructed without due attention to sealing joints and around penetrations, the
opportunity for moisture ingress into the loft space and consequent risk of condensation
occurring is increased. This is also true of conventionally ventilated constructions where the
effect of wind movement over the roof can reduce the air pressure in the loft space and ‘suck’
moisture laden warm air from the living space into the loft space. However it is recognised
that the rate of moisture removal via the ventilated and unventilated approach is not the same.
It is therefore important that the ceiling is sealed to an appropriate level. BBA computer
modelling of the behaviour of roofs has assumed effective ceiling ‘defect’ areas of up to 10
square mm per square metre of ceiling. See also Q/A 6, 7 and 11.
There are reports concerning ‘flapping-noise’ in roofs incorporating some types of permeable
roof tile underlay membranes in certain wind conditions. The BBA has, however, only
received a very limited number of reports in this regard and therefore do not view it as a
fundamental problem.
Awarenessnetworks GlassBuy IeTrade P1 P2 P3 Lead LiveSpace Blonder Meebq Maverick Bruce
Zegna Nings Cilo 385857762 SoulCast SpotsDir DreamHome EcTrade MySpace Exportnation
PerfectCondoz Myekoo Efreedir Fukesi CleverDir blogtext Ca-Yahoo Uk-Yahoo Uk-Yahoo-Po Au-Yahoo May 07 How widely are they used and in what applications ?
A2 Breather membranes have been used abroad in construction since the 1970’s.
Membranes were first Certified by the BBA in 1982 as sheathing membranes for timber frame
walls and as roof tile underlays in conventionally ventilated cold roofs. They were
subsequently approved as roof tile underlays in warm roof constructions in 1982 and most
recently in cold non ventilated roof constructions in 1999. At the time of writing this article,
Certificates for roof tile underlays used as part of a cold unventilated pitched roof system in
dwellings have been issued as shown in Table 1
Table 1 – BBA Certificates issued for cold unventilated roof applications (at 15.03.04)
Certificate No. Product name Certificate holder
99/3648 Daltex Roofshield Don & Low Ltd Nonwovens
00/3749 Permo Forte Klober Ltd
01/3842 Global Breather Roof Tile
Underlay
EBC UK Ltd
03/4017 Breathline Vapour permeable
Underlay
Knauf Insulation Ltd
03/4062 Monarperm 700 Icopal Ltd
04/4078 - DS3 VapR-free underlay Mercury Building products Ltd
04/4101 Tyvek Universal Underlays DuPont de Nemours (Luxembourg) Sarl
Details of approved products can be found on www.bbacerts.co.uk or by phoning the BBA
hotline on 01923 665400. Users are advised to check the validity of Certificates and any
limitations on the scope of the approval.
Q3 Can they be used simply ‘instead’ of conventional eaves ventilation ?
A3 Only if a number of measures are taken to limit the ingress of water vapour into the
unventilated space. In this regard, the roof system must be considered as a whole from ceiling
to roof tiles, including the following design points:
- all penetrations into the roof space must be properly sealed
- loft hatches must incorporate effective compressible draught seals
- the rooms below the ceiling must include provision for the dispersal and rapid dilution of
water vapour in accordance with the Building Regulations, including extractor fans in
rooms that may experience high humidity
- All water tanks in the loft space must be covered
- Any vent pipes should be arranged so that they do not discharge water vapour into the loft
space
See also Q&A10 to 15 and the relevant BBA Certificate for conditions of approval.
Q4 What are the advantages of using the unventilated system ?
A4 One of the main advantages is reducing the amount of heat lost by air leakage through the
ceiling and from the loft space to the outside. Up to 25% of the heat lost through a
conventional roof system is by this mechanism. The unventilated roof ‘system’ will reduce
this mechanism of heat loss, more so if the underlay laps are sealed.
In addition, not having to provide eaves and ridge ventilation can help to save time and cost
on site and can give a more desirable appearance to the finished roof.
Q5 What are the disadvantages of using the system ?
A5 Extra time and care is needed to ensure that penetrations into the ceiling are properly sealed
and that the loft space is protected from sources of water vapour, in accordance with the
requirements of the Certificate. See also A3.
If the ceiling is constructed without due attention to sealing joints and around penetrations, the
opportunity for moisture ingress into the loft space and consequent risk of condensation
occurring is increased. This is also true of conventionally ventilated constructions where the
effect of wind movement over the roof can reduce the air pressure in the loft space and ‘suck’
moisture laden warm air from the living space into the loft space. However it is recognised
that the rate of moisture removal via the ventilated and unventilated approach is not the same.
It is therefore important that the ceiling is sealed to an appropriate level. BBA computer
modelling of the behaviour of roofs has assumed effective ceiling ‘defect’ areas of up to 10
square mm per square metre of ceiling. See also Q/A 6, 7 and 11.
There are reports concerning ‘flapping-noise’ in roofs incorporating some types of permeable
roof tile underlay membranes in certain wind conditions. The BBA has, however, only
received a very limited number of reports in this regard and therefore do not view it as a
fundamental problem.
Awarenessnetworks GlassBuy IeTrade P1 P2 P3 Lead LiveSpace Blonder Meebq Maverick Bruce
Zegna Nings Cilo 385857762 SoulCast SpotsDir DreamHome EcTrade MySpace Exportnation
PerfectCondoz Myekoo Efreedir Fukesi CleverDir blogtext Ca-Yahoo Uk-Yahoo Uk-Yahoo-Po Au-Yahoo A1 The particular membranes in question typically comprise spunbonded polypropylene or
spunbonded polypropylene/polyethylene laminated either side of a micro-porous
polypropylene or polyethylene film.
Monolithic spunbonded membranes are also used. They have a structure that is sufficiently
fine to prevent liquid water penetration in service conditions, but not too fine to prevent the
transfer of water vapour (molecules of water in air), see figure 1.
All materials, including vapour control layers, have a finite permeability to water vapour
transfer. However, in the context of this Article, a breathable membrane is a material which, in
service conditions, is sufficiently permeable to water vapour transfer to adequately limit the
risk of condensation in roofs.
Current published definitions include the following:
BS 5250: 2002 section 3.2 “Breather membrane” – vapour permeable membrane with a
vapour resistance less than 0.6 MNs/g. The Standard goes on to describe the use of ‘Breather
membranes’ in walls.
BS 5250: 2002 section 3.26 “Vapour permeable underlay” – Pitched roof underlay which
meets the recommendations of BS 5534-1 and NFRC TB6 and is additionally water vapour
permeable with a vapour resistance of less than 0.25 MNs/g
These two figures can also be expressed as water vapour transmission rates of at least 341 or
820 g/m2/day respectively, when tested under standard conditions of 25o C and humidity of 0%
rh and 75% rh on each side of the membrane.
Figure 1 – Breather membrane
The function of these membranes is to provide all of the normal demands made on a roof
underlay and at the same time allow water vapour egress without making specific provision
for ventilation. See also Q/A3.
Q2 How widely are they used and in what applications ?
A2 Breather membranes have been used abroad in construction since the 1970’s.
Membranes were first Certified by the BBA in 1982 as sheathing membranes for timber frame
walls and as roof tile underlays in conventionally ventilated cold roofs. They were
subsequently approved as roof tile underlays in warm roof constructions in 1982 and most
recently in cold non ventilated roof constructions in 1999. At the time of writing this article,
Certificates for roof tile underlays used as part of a cold unventilated pitched roof system in
dwellings have been issued as shown in Table 1
引用
Breathable membrane for house roof
Breathable membranes have been used in buildings for many years now and, more recently, in cold
pitched roof constructions without traditional eaves ventilation. The benefit of reduced heat loss and
not having to incorporate ventilators has seen their use grow but at the same time has attracted
noticeable comment both from supporters of the application and from detractors who favour traditional
ventilation solutions.
What is a breather membrane and how does it work ? A1 The particular membranes in question typically comprise spunbonded polypropylene or spunbonded polypropylene/polyethylene laminated either side of a micro-porous polypropylene or polyethylene film. Monolithic spunbonded membranes are also used. They have a structure that is sufficiently fine to prevent liquid water penetration in service conditions, but not too fine to prevent the transfer of water vapour (molecules of water in air), see figure 1. All materials, including vapour control layers, have a finite permeability to water vapour transfer. However, in the context of this Article, a breathable membrane is a material which, in service conditions, is sufficiently permeable to water vapour transfer to adequately limit the risk of condensation in roofs. Current published definitions include the following: BS 5250: 2002 section 3.2 “Breather membrane” – vapour permeable membrane with a vapour resistance less than 0.6 MNs/g. The Standard goes on to describe the use of ‘Breather membranes’ in walls. BS 5250: 2002 section 3.26 “Vapour permeable underlay” – Pitched roof underlay which meets the recommendations of BS 5534-1 and NFRC TB6 and is additionally water vapour permeable with a vapour resistance of less than 0.25 MNs/g These two figures can also be expressed as water vapour transmission rates of at least 341 or 820 g/m2/day respectively, when tested under standard conditions of 25o C and humidity of 0% rh and 75% rh on each side of the membrane. The function of these membranes is to provide all of the normal demands made on a roof
underlay and at the same time allow water vapour egress without making specific provision
for ventilation.
Awarenessnetworks GlassBuy IeTrade P1 P2 P3 Lead LiveSpace Blonder Meebq Maverick Bruce
Zegna Nings Cilo 385857762 SoulCast SpotsDir DreamHome EcTrade MySpace Exportnation
PerfectCondoz Myekoo Efreedir Fukesi CleverDir blogtext Ca-Yahoo Uk-Yahoo Uk-Yahoo-Po Au-Yahoo April 30 Breathable membranes have been used in buildings for many years now and, more recently, in cold
pitched roof constructions without traditional eaves ventilation. The benefit of reduced heat loss and
not having to incorporate ventilators has seen their use grow but at the same time has attracted
noticeable comment both from supporters of the application and from detractors who favour traditional
ventilation solutions.
What is a breather membrane and how does it work ? A1 The particular membranes in question typically comprise spunbonded polypropylene or spunbonded polypropylene/polyethylene laminated either side of a micro-porous polypropylene or polyethylene film. Monolithic spunbonded membranes are also used. They have a structure that is sufficiently fine to prevent liquid water penetration in service conditions, but not too fine to prevent the transfer of water vapour (molecules of water in air), see figure 1. All materials, including vapour control layers, have a finite permeability to water vapour transfer. However, in the context of this Article, a breathable membrane is a material which, in service conditions, is sufficiently permeable to water vapour transfer to adequately limit the risk of condensation in roofs. Current published definitions include the following: BS 5250: 2002 section 3.2 “Breather membrane” – vapour permeable membrane with a vapour resistance less than 0.6 MNs/g. The Standard goes on to describe the use of ‘Breather membranes’ in walls. BS 5250: 2002 section 3.26 “Vapour permeable underlay” – Pitched roof underlay which meets the recommendations of BS 5534-1 and NFRC TB6 and is additionally water vapour permeable with a vapour resistance of less than 0.25 MNs/g These two figures can also be expressed as water vapour transmission rates of at least 341 or 820 g/m2/day respectively, when tested under standard conditions of 25o C and humidity of 0% rh and 75% rh on each side of the membrane. The function of these membranes is to provide all of the normal demands made on a roof
underlay and at the same time allow water vapour egress without making specific provision
for ventilation.
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