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SITE GUIDE
siteB a s e m e n t
w a t e r p r o o f i n g
guide
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F o r e w o r d
This publication is one of a series related to basements for housing. It has been produced under the direction of the
Basement Development Group, which was initiated and is co-sponsored by the British Cement Association.
A c k n o w l e d g e m e n t s
The British Cement Association (BCA) is grateful to the British Structural Waterproofing Association (BSWA) for co-
sponsoring this publication. It is also grateful for the assistance and comments provide by members of the Basement
Development Group and to the considerable work of its Waterproofing Task Group in drafting and progressing this
publication. Thanks are also extended to all others who provided input to and comments on the preparatory drafts.
B a s e m e n t D e v e l o p m e n t G r o u p W a t e r p r o o f i n g T a s k G r o u p
B Aspin (Chairman), House Builders Federation
A K Tovey (Secretary), Tecnicom
F Atkins, National Housebuilding Council
D Burke, Zurich Municipal
M Clarke, British Cement Association
P Hart, Institute of Building Control
D James, Bovis Homes South West
A Jones, Stewart Milne Group Limited
B Keyworth, Architect
R S Reynolds, Institute of Clerks of Works
G R Sharpe, Association of Building EngineersP Trotman, Building Research Establishment
A K Tovey (Chairman), Tecnicom
S Brown, Sika Limited
V Connolly, Renlon Limited
M Falla, Booth Engineering Services Limited
Z Ginai, Marley Waterproofing Limited
P Hewitt, Vandex UK Limited
T Holloway, Renlon Limited
M Lenaghan, Servicised Limited
I J Moffat, Fosroc Expandilte Limited
J A M Padley-Smith, Mastic Asphalt Council and
Employers Federation Ltd
A J Parker, SCL Group Limited
M Radford, RIW Limited
S u p p o r t i n g T r a d e G r o u p sAutoclaved Aerated Concrete Products Association
British Structural Waterproofing Association
Concrete Block Association
Mortar Producers Association
Ready-mixed Concrete Bureau
Many construction activities are potentially dangerous, so care is needed at all times. Current legislation requires all
persons to consider the effects of their actions or lack of action on the health and safety of themselves and others. Advice
on safety legislation may be obtained from any of the area offices of the Health and Safety Executive.
48.059
First published 1994
ISBN 0 7210 1476 3
Price group D
British Cement Association 1994
Published by
British Cement Association
Century House, Telford Avenue
Crowthorne, Berks RG11 6YS
Telephone (0344) 762676
Fax (0344) 761214From April 1995 the code will be (01344)
All advice or informat ion f rom the Br i t i sh Cement Associa t ion i s in tended for those who wi l l evaluate the s igni f icance and l imi ta t ions of i t s contents and take responsibi l i ty for i t s use and
appl ica t ion. No l iabi l i ty ( inc luding tha t for negl igence) for any loss resul t ing f rom such advice or informat ion i s accepted. Readers should note tha t a l l BCA publ ica t ions are subjec t to revis ion
from time to time and should therefore ensure that they are in possession of the latest version.
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C o n t e n t s
Product ion: Words & Pages
I n t r o d u c t i o n
Scope
P r i n c i p l e s o f d e s i g n a n d i n s t a l l a t i o n
G e n e r a l
Contract details
Site information
C o n s t r u c t i o n c a t e g o r y
Further considerationsBasement and site drainage
A p p l i c a t i o n o f w a t e r p r o o f i n g s y s t e m s -
D O S a n d D O N T s
General to all systems
Category 1: Bonded sheet membranes
Category 2: Cavity drain membranes
Category 3: Bentonite clay active membranes
Category 4: Liquid-applied membranes
Category 5: Mastic asphalt membranes
Category 6: Cementitious crystallization active
systems
Category 7: Proprietary cementitious multi-coat
renders, toppings and coatings
Geocomposite drainage systems
G l o s s a r y
R e f e r e n c e s
2
2
3
21
2 1
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I n t r o d u c t i o n
The benefits of basements, and their viability and costs
were examined in a previous report(1 )
. This indicated that
they can be economically introduced onto most sites. In
particular, it showed they have clear advantages where
the ground is poor and might otherwise be difficult and
possibly uneconomic to build on. However, to ensure
success, particular attention must be given to the design
and construction of the basement and any necessarywaterproofing. This publication provides specific
guidance on the site application or installation of the
various waterproofing systems and comments on other
associated construction matters.
A companion publication, Base ment wa te rp ro of ing:
Des ign guide(2)
, gives design information to help the
builder or building designer decide which construction
technique and waterproofing method offer the best
solution, and to help them avoid unsuitable construction.
Scope
The details and comments in this publication relate to
the categories of structural waterproofing which provide
Grade 2 or 3 internal environments, as defined in
BS 8102, which are appropriate for residential basements.
A Grade 2 environment is for use as workshops, plant
rooms and other areas where the performance level
permits no water penetration but where higher levels of
water vapour would be tolerable and surface
condensation may occur.
A Grade 3 environment is for ventilated residential and
working areas which require a drier environment.
P r i n c i p l e s o f d e s i g n a n di n s t a l l a t i o n
G e n e r a l
Applying or installing a waterproofing system are
specialist tasks that are just as important as choosing and
specifying the system. The manufacturer should have
been consulted early in the design stage to ensure that
the most appropriate system has been selected. The
manufacturer will also be able to carry out the
installation or to recommend specialist waterproofing
contractors familiar with the system to be used.
Installation or application should not be left to
inexperienced workers.
The British Structural Waterproofing Association can
provide details of manufacturers of various waterproofing
systems and of appropriate specialist waterproofing
contractors.
Contract detai ls
The specialist waterproofing contractor should examine
the contract drawings and waterproofing specifications to
ensure the design requirements are completely
understood. Since the designer should have consulted
with the manufacturer of the waterproofing system
during the design, there should be no obvious errors in
the contract details. However, the important thing is that
the final construction should perform satisfactorily. The
specialist waterproofing contractor should therefore
establish that the waterproofing concept does enable a
continuous barrier to be created - or otherwise
2
adequately protects the structure - and is practicable to
install.
Unless otherwise agreed with the designer, the materials
and installation should be in accordance with the
specified details, and all work should be carried out to
the same high standards irrespective of the Grade of
internal environment. All junctions, service penetrations,
dpc/cavity tray junctions and laps in materials should be
formed according to the designers or manufacturers
details.
The specialist waterproofing contractor should not use
alternative waterproofing systems or membranes since
they may not be appropriate for the conditions. For
example, the system may have been selected to resist not
just wat er but a specifi c ground chemi cal. Sim ilarly, any
protection boards or screeds should comply with the
specifications and be positioned as on the drawings.
In essence, no alterations should be made to the
specified materials, their relative position and installation
sequence, without clearance from the designer or the
manufacturer of the waterproofing system.
Si te informat ion
Before the form of construction and the necessary
waterproofing system can be chosen, information must
be gathered on soil type, water tables and other relevant
factors. This is the designers responsibility.
The main contractor should find out from the designer
what the site conditions are - particularly the likely
severity of ground water conditions, and pass this
information to the specialist waterproofing contractor.
Sometimes, the main contractor may need to lower the
water table temporarily or permanently to enable
construction and waterproofing to go ahead.
Any lowering of the water table will need to be
maintained until the loads acting on the basement, from
either itself or in combination with the superstructure,
are greater than the forces that would be generated by
the water pressures as the water table returns to its
original level.
Although a site survey will have determined the general
nature of the site, there may be local variations. Any
significant differences should be brought to the attention
of the designer as they may create an additional hazard
not previously taken into account. Changes from
impervious to permeable soils may produce unexpected
water channels. Similarly, interception of previous landdrains or other elements could increase the amount of
water present. Any unexpected chemicals or suspect
materials should also be brought to the designers
attention.
Construct ion category
The structural walls will usually fall into one of the
following three construction categories.
Type A (tanked protection) structures will often be of
masonry construction, although plain or reinforced
concrete may be used. The latter may be in-situ or
precast. The structure is regarded as having no integral
protection against water ingress and so relies on the
applied waterproofing system to provide the necessary
control. Masonry walls may need a cement rendering or
flush pointing to product an acceptable surface for
subsequent application of the waterproofing system.
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The waterproofing system will , depending on its type,
tolerate certain construction cracks or minor defects. Fine
hair-line cracks up to 0.3 mm wide in reinforced
construction will generally be acceptable. Any larger or
unusual cracks should be brought to the designers
attention to allow for possible remedial action before the
waterproofing system is installed or applied.
Type B (structurally integral protection) structures will
generally be of reinforced or prestressed concrete. Since
they are specifically designed to be water-resistant,further waterproofing will be required only where
additional control against free water or water vapour is
considered necessary. In some instances, the additional
protection may be used to safeguard the structure from
aggressive chemicals. Again, any noticeable cracking or
defect should be brought to the attention of the designer.
Type C (drained protection) structures incorporate a
drained cavity in the basement. Although defects in the
outer leaf will not usually create problems, they may
allow more water to enter the cavity. If too much enters,
this might overload the cavity drain and lead to water
penetrating the basement. The drainage channels must
be properly formed and positioned, be free from
obstructions, and be approved under test. Any defect or
suspect area in the outer leaf should be raised with the
designer before the inner cavity drain system is installed.
The surface of concrete floors or oversite should be
prepared to suit the particular waterproofing system to
be used.
Further considerations
Control of condensation
Because window areas are often reduced, there tends to
be less natural ventilation in basements than in other
parts of the structure. The designer will pay particular
attention to this and detail specific heating and
ventilation measures. It is important that any ventilation
system is properly installed and not obstructed by
waterproofing systems inside the structure.
The waterproofing system must be installed where
indicated by the designer as otherwise there could be
excessive interstitial or surface condensation.
System restraint
Some waterproofing systems need to be restrained so
that they can resist the hydrostatic pressure. The mass
and thickness of such restraint must comply with thedesigners or manufacturers details.
Chemical barriers
An externally applied membrane may have been
specified to resist the effects of aggressive chemicals in
the soil. It must not be replaced by any other membrane
or system without the designers approval.
Mo ve me nt jo in ts
The designer is advised to eliminate movement joints in
the basement substructure wherever possible. Where
they are incorporated, details should have been includedin the contract drawings and must be followed exactly. If
the specialist waterproofing contractor finds movement
joint s with no speci fic waterpro ofing detail s, the designer
must be asked to provide appropriate details. On no
account should a waterproofing system be continued
directly across movement joints.
Construction joints
Where reinforcement crosses construction joints in
reinforced concrete structures, the joints are not
movement joints and most waterproofing membranes
may be directly placed across them. With Type B
construction, these joints will often be provided with a
waterstop, either within the concrete or on its surface.
Service penetrations
Any service penetration through the basement wall or
lower floor slab will need special details.
It is important to ensure that service penetrations are
correctly formed and sealed in accordance with the
specification or manufacturers instructions. On no
account should penetrations be made or their
waterproofing attempted without proper details being
followed and agreed with the designer and manufacturer
of the waterproofing system.
Ba se me nt a n d s i t e dr a ina g e
Sometimes, installing a waterproofing system may mean
that the area around the basement has to be drained. In
any case, it is generally good practice to provide
perimeter drains to enable any excess percolating water
to run away - for example to the downside of a sloping
site or to a lower soakaway.
Since such drainage may be an essential part of the
waterproofing measures, it is generally advisable to make
sure this has been installed before the waterproofing
system is applied or installed.
Application of waterproofing systems - DOs and DONTs
Each waterproofing system has its own characteristics and application methods. In addition, each has procedures
which should be adhered to (dos) and aspects which may later lead to defects or problems ( donts) . These are
listed by category on the following pages, followed by some dos and donts for geocomposite drainage systems.
General to all systems
1 Bonded sheet membranes
2 Cavi ty dra in membranes
3 Bentonite clay active membranes
4 L iquid-appl i ed membranes
5 Mastic asphalt membranes
6 Cementitious crystallization active systems
7 Proprietary cementitious multi-coat renders,toppings and coatings
Geocomposite drainage systems
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G e n e r a l
A: He al th & Safe ty
D O s
OBTAIN Health & Safety product and equipment data, and have available on site
HAVE protective clothing, cleansing creams, etc. on site
DISPOSE of release paper, cores, primer tins, etc. properly
STORE gas bottles in a compound with high, secure fencing
ENSURE adequate ventilation to interior during working (particularly when asphalting)
PROVIDE respiratory protection where necessary
OBSERVE good housekeeping and general hygiene guidelines
KEEP materials out of reach of children
D O N T s
DO NOT ignore Health & Safety advice
DO NOT leave waste on site
DO NOT burn scrap
DO NOT transfer materials into unlabelled containers
POSSIBLE CONSEQUENCES
Accidents - personal injury, prosecution
Third-party injury, prosecution
Irritation from smoke and dust
Improper handling and disposal of unidentifiable
materials and risk of injury
DO NOT expose materials to heat or flame
DO NOT dispose of waste or surplus materials
incorrectly
Fire, explosion (primers) and severe personal injury
Environmental/legal considerations
B: I n f o rm a t io n
D O s
ENSURE that detail drawings, manufacturers literature and site instructions are available to operatives on site
CHECK that all information and details are in accordance with the waterproofing manufacturers instructions
SEEK advice and guidance from manufacturer on installation procedures
ENSURE specification conforms with the manufacturers recommendations
CONSULT the manufacturer, if in doubt
D O N T s
DO NOT confine information to the site hut
DO NOT start waterproofing until all the available
information has been read and understood
POSSIBLE CONSEQUENCES
Waterproofing failure
Leakage
DO NOT assume that a manufacturer has been
consulted in the design, even where specified. The
concept or design may be basically flawed (see
Ba se ment wa terp ro of in g: Desi gn gu id e)
Litigation
DO NOT apply membrane without consulting the Incorrect application leading to potential failure and
manufacturers literature. financial loss
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C: Associated works
D O s
ENSURE that associated works are co-ordinated and do not impede or damage waterproofing
CHECK that other products and methods are compatible
TAKE CARE not to damage system, but repair simple defects according to manufacturers instructions
ALWAYS refer to manual
PROVIDE for attendance of other trades where specified
ARRANGE for hoisting facilities and any necessary scaffolding or other plant
PROVIDE suitable surface for application
ENSURE that measures taken will not interfere with the watertightness of the system
DONTs
DO NOT proceed if unsure of next stage or of its effect
on work in hand
DO NOT drag steelwork across unprotected work
DO NOT expect installers to provide services normally
provided by other trades
POSSIBLE CONSEQUENCES
Damage, leakage, or longer-term adverse reactions
between materials
Damage or leakage
Poor workmanship
DO NOT pierce or breach waterproofing system
DO NOT introduce non-specified chemicals, etc.
DO NOT introduce any necessary vibration, heat, cold
or pressure until the system will accept this
Leakage
Harm to waterproofing system
Damage to membrane by imposed loads
DO NOT change drainage details without considering
the waterproofing system
DO NOT mix waterproofing systems, even if specified -
refer to client, designer or manufacturer
DO NOT continue if the continuity of the membrane has
been broken
Development of water pressures incompatible with
forms of construction
Failure through incompatibility of hybrid systems
Damp/water penetration
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1 B o n d e d s h e e t m e m b r a n e s
1A: Storage and handl ing
D O s
STORE as required by the manufacturer
RECORD batch numbers to check shelf life
STORE upright
KEEP in controlled temperature
FOLLOW manufacturers instructions and check that all ancillary items, tools and protective clothing are present on site
DONTs
DO NOT leave out on site or allow rolls to become cold
or wet
DO NOT use after shelf life expired
DO NOT store rolls horizontally
DO NOT allow material to get too cold
DO NOT allow material to get too hot
DO NOT mix products and ancillary items from different
manufacturers
1B: Preparation of substrates
POSSIBLE CONSEQUENCES
Difficulty in stripping release paper and probably poor
adhes ion
As above
Edges of sheet become damaged and rolls become
difficult to strip and lay
Material could lose its adhesion
May become too sticky and prove difficult to lay
Incompatibility or unsuitability, with no redress in case
of failure
INSPECT surface to be waterproofed. Does it meet manufacturers requirements for finish, imperfections and othercriteria?
CHECK whether in accordance with drawings, especially provision of chamfers at corners/edges and chases for
terminations
ENSURE that surface is free from all contaminants (mud, wet, release agents, curing compounds, etc.) and in
accordance with manufacturers requirements
AVOID awkward details
ALLOW enough time for curing
ALLOW for temporary weather protection in order to provide dry surfaces
PLAN works to prevent membrane being left exposed for long period of time
D O N T s
DO NOT accept just any degree of finish
DO NOT waterproof over blow holes, poorly
compacted concrete or where brickwork or blockwork
has not been flush pointed
DO NOT accept surfaces not in accordance with
manufacturers details (absence of chamfers/chases, etc.)
POSSIBLE CONSEQUENCES
Membrane puncture under load
Membrane not sandwiched correctly
Leakage
DO NOT dress membrane around an impossible detail
DO NOT lay on uncured background
DO NOT take on the contract unless you are happy the
membrane will be protected and that a suitable lap will
be left to connect to
Leakage
Membrane not bonded to background surface
Your company will get the blame for foreseen leaks
6
D O s
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1C: Applicat ion
MAKE SURE the correct primer is applied, following the instructions for number of coats and coverage rate
ALLOW primer to dry for the required length of time before applying membrane
ENSURE that reinforcing strips, angle fillets, etc. are used at changes in direction and are as required by manufacturer
ENSURE that all specified laps are provided and are rolled down
ENSURE that all laps are weathered
FOLLOW manufacturers instructions for laying membrane
ALWAYS check what is required as a minimum loading coat, since the membrane is designed to be sandwiched
D O N T s
DO NOT omit primer on horizontal surfaces unless
agreed by manufacturer
DO NOT stretch the primer application
DO NOT prime more than can be waterproofed in the
same day
DO NOT omit reinforcing strips, etc. at corners to save
cost
POSSIBLE CONSEQUENCES
Subsequent defects in unbonded sheets provide a path
for water ingress
Inadequa te bond
Contamination with site dust/condensation/rain resulting
in lack of adhesion
Leakage
DO NOT omit or skimp on edge or end laps
DO NOT just unroll and drop down a vertical surface
Leakage paths
Air pockets behind the membrane
1D: Protect ion and backfi l l ing
USE appropriate or specified protection and apply carefully to prevent damage
PROP or backfill in sequence when using board protection
USE specified backfill material
COMPACT in layers as specified
ALWAYS USE a suitable protection board, of the correct thickness to avoid damage, spot-bonded to the membrane
DISCUSS the backfilling procedure with the site manager or design team. If this work is to be done by others,
arrange to be present to check for site damage
ENSURE that the backfilling does not impede a lap joint that you may have to work from later
D O N T s POSSIBLE CONSEQUENCES
DO NOT store materials on unprotected membrane
DO NOT tip waste material as backfill
Leakage from punctured or damaged membrane
Settlement and downward displacement of protection
board and membrane
As aboveDO NOT backfill without compacting layers as specified
DO NOT apply protection to damaged membrane
without first making repairs
DO NOT leave a sheet membrane unprotected
DO NOT drill or puncture surface without checking with
the installer
Leakage failure
Subsequent problems, since damage - whether
intentional or not - often goes unrecorded
Loss of waterproofing integrity of the membrane and
potential for leakage
7
D O s
D O s
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2 C a v i t y d r a i n m e m b r a n e s
2A: Storage and handl ing
D O
STORE as required by the manufacturer
D O N T s POSSIBLE CONSEQUENCES
DO NOT leave drainage sheets around on site Damage
DO NOT allow ancillary sealing tapes to become cold Difficulty stripping release paper and probably poor
or wet adhes ion
2B: Preparat ion of substrates
D O s
CHECK and remedy unacceptable leaks in concrete or masonry substrate before the system is installed
CLEAN horizontal substrate and remove all debris
CHECK there are no depressions in floor slab which may cause ponding
ENSURE slab drains to drainage exits and pump sump
D O N T s
DO NOT lay membrane over unswept substrate
DO NOT lay cavity former over uneven floor surface
2C: Applicat ion and f ini shing
POSSIBLE CONSEQUENCES
Blockages
Damage and ponding, leading to leakage
D O s
CHECK total integrity of cavity drainage system and inspect membrane for damage before placing screeds or
blockwork finishes
ENSURE that mesh reinforcement (if required) for floor screeds is supported
ERECT walkways to support access and barrows for placing screeds
CHECK and clean out all drainage points/channels
ENSURE sump pump (where provided) is operational
D O N T s POSSIBLE CONSEQUENCES
DO NOT shorten recommended overlaps
DO NOT omit recommended sealing strips and tapes
DO NOT omit sealing washers for mechanical fixings
DO NOT store materials on completed installations or
traffic unnecessarily
Water and moisture penetration
As above
As above
Puncture of membrane
DO NOT allow fixing through finished floor screeds, or
unauthorised channels in the finished loading screed
DO NOT allow additional masonry wall ties without
sealing washers
DO NOT allow membrane and finishes over membrane
to be carried out by two different parties
Cavity membrane will not be loaded correctly
Leakage
A meaningful guarantee could not be issued by the
membrane installer
8
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2D: Protect ion and backfi l l ing
D O s
CHECK integrity of cavity drainage system before proceeding
AT WALLS, construct non-loadbearing blockwork wall in front of cavity drainage system
AT FLOORS, keep to specified screed thickness, reinforced if required
ENSURE that reinforcement mesh is supported and has not damaged cavity drainage system while being positioned
D O N T s POSSIBLE CONSEQUENCES
DO NOT proceed until everything has been inspected
and any damage repaired
Water penetration at damaged areas
DO NOT use ties unless properly sealed
DO NOT drag reinforcing mesh across cavity drainage
sys tem
Water penetration at ties
Damage and perhaps water penetration
9
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3 B e n t o n i t e c l a y a c t i v e m e m b r a n e s
3A: Storage and handl ing
D O s
STORE materials off the ground
KEEP dry before use
USE gloves when handling loose bentonite
D O N T POSSIBLE CONSEQUENCES
DO NOT place materials in standing water Prehydration and need for replacement
3B: Preparat ion of substrates
D O
MAKE reasonably flat and free from voids
D O N T
DO NOT leave stones or voids larger than 50 mm
POSSIBLE CONSEQUENCES
Waterproofing efficiency impaired
3C: Appl icat ion and f inishing
D O s
REFER to manufacturers fixing guide
BRUSH standing water from substrate or blinding
ALWAYS lap panels
PROTECT from heavy steelwork
LAY only what can be covered in one day
WET the cut surfaces
D O N T s POSSIBLE CONSEQUENCES
DO NOT lay panels in standing water
DO NOT place panels on unrendered masonry surfaces
DO NOT walk on wet panels
DO NOT drag heavy objects across panels
DO NOT leave exposed for more than 48 hours
DO NOT lay large areas and leave uncovered
Prehydration and replacement needed
Loss of bentonite into voids. Loss of efficiency
Need for replacement
Damage - loss of bentonite
Prehydration and need for replacement
Prehydration and need for replacement
10
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3D: Protect ion and backfi l l ing
D O s
USE hardboard in specific circumstances (but not normally required)
USE sand if possible, but nothing larger than 50 mm (MOT Type II is acceptable)
ALWAYS compact well
D O N T s
DO NOT use plastic sheeting or prevent water
reaching the system
POSSIBLE CONSEQUENCES
System takes longer to react
DO NOT leave large voids, or forget to compact Waterproofing efficiency impaired
1 1
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4 L i q u i d - a p p l i e d m e m b r a n e s
4A: Storage and handl ing
D O s
PROVIDE dry, safe storage away from sources of ignition
RECORD ba tch numbers
KEEP in controlled temperature
ROTATE stock
D O N T s
DO NOT STORE longer than 12 months
DO NOT USE beyond shelf life without consulting the
manufacturer
P O S S I B L E C O N S E Q U E N C E S
Some loss of solvents, causing increase in viscosity
As above
4B : Preparation of substrates
D O s
DRY surface to depth of 1-2 mm
REMOVE dust, grease, oils and other contaminants
ELIMINATE all hollows and voids
FLUSH-POINT masonry walls
REMOVE sharp edges or high points
REMOVE existing floor or masonry paints
PROVIDE 20 mm sand/cement fillet in all internal angles
FOLLOW manufacturers recommendations for surface flatness, keeping it generally within 3-4 mm
ALLOW for temporary weather protection in order to provide dry surfaces
PLAN works to prevent membrane being left exposed for long periods
D O N T s
DO NOT apply to wet surfaces
DO NOT apply to a dusty or flaking surface
DO NOT apply to open-textured surface
DO NOT tamp surface heavily
POSSIBLE CONSEQUENCES
Membrane will not bond to substrate
Membrane will not bond to substrate or may not leave
the brush
Continuity of membrane will be broken
Will cause pooling in low points
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4C: Appl icat ion and f inishing
D O s
PREPARE surface correctly
REFER to manufacturers recommendations in cold conditions
APPLY at published coverage rates
APPLY in two coats
ALLOW each coat to dry throughout its thickness
REINFORCE angles where necessary
ALWAYS employ a preferred applicator, who is conversant with the product
D O N T s
DO NOT apply when temperature is below 5C
DO NOT pour onto substrate or apply thickly
DO NOT sand membrane
DO NOT screed until cured
DO NOT leave exposed to UV light for more than
28 days
DO NOT apply the material too thinly
POSSIBLE CONSEQUENCES
Surface may frosty, i.e. wet
Trapped solvent and failure to cure
Breaks continuity of membrane
Membrane will be absorbed into screed
Membrane will weather, become thin and brittle
Membrane will not function as designed but instead
will leak
DO NOT apply a second coat before the first is fully
cured
4D: Protect ion and backfi l l ing
Will damage continuity of first coat and cause solvent
ent rapment
D O s
Externa l pro tect ion
USE bitumen-impregnated fibre board horizontally
USE geotextile drainage board vertically
Interna l ly
REINFORCE slab or screed horizontally
ADD masonry skin with 20 mm cavity filled with sand/cement mortar as work proceeds
In all cases
ALWAYS allow for suitable protection which should be provided by the company laying the membrane
ENSURE protection is firmly fixed according to manufacturers recommendations
MONITOR the backfilling process to reduce risk of damage
D O N T s POSSIBLE CONSEQUENCES
DO NOT lay protection boards loosely
DO NOT leave exposed to backfilling or unprotected
against following trades
Movement, exposing membrane
Damage to the membrane
DO NOT leave membrane unsupported internally Membrane will blow, leading to failure
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5 M a s t i c a s p h a l t m e m b r a n e s
5A: Storage and handl ing
D O s
PROVIDE dry, safe storage for primers, gauges, tools, etc.
POSITION plant close to point of application
PLACE mastic asphalt blocks tidily near to asphalt mixer
D O N T
DO NOT increase the distance that molten material is
carried
POSSIBLE CONSEQUENCES
Material could cool down and become difficult to lay
5B: Preparat ion of substrates
D O S
PROVIDE base to specified levels, tolerances and finish
APPLY float finish to horizontal surfaces
ENSURE adequate chases
PROVIDE correctly prepared vertical surfaces
ENSURE all oils, greases and contaminates are removed from all surfaces
D O N T
DO NOT penetrate horizontal or vertical surfaces with
services
POSSIBLE CONSEQUENCES
Leakage failure around pipes
5C: Ap p l i c a t io n
D O s
ENSURE all horizontal and vertical work is applied in three coats
PIERCE and make good any blows while mastic asphalt is still warm
ENSURE all succeeding coats follow the preceding coats without delay
D O N T s
DO NOT allow temperature of remelt to exceed 230C
for sustained periods
DO NOT lay membrane on wet background
DO NOT lay successive coats on cold or contaminated
preceding coats
DO NOT lay on dusty surfaces
POSSIBLE CONSEQUENCES
Adverse effect on viscosity of bitumen
Unacceptable increase in blowing
Lack of bond and contamination between coats
Unacceptable increase in blowing
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5D: Protect ion and backfi l l ing
D O s
PROVIDE protective screed to horizontal asphalt work as soon as practicable after laying
PROVIDE vertical brickwork protection and concrete loading coat designed to withstand the expected water pressure
on internally applied tanking,
MAINTAIN sump with pump facility until all loading is complete - if water pressure present
D O N T s
DO NOT backfill externally without protection to the
vertical asphalt
DO NOT store materials, reinforcement, etc. on
unprotected membrane or allow it to be trafficked
POSSIBLE CONSEQUENCES
Damage to asphalt by other trades, before and during
backfilling
Puncture damage or cracking
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1 6
6 C e m e n t i t i o u s c r y s t a l l i z a t i o n a c t i v e s y s t e m s
6A: Storage and handl ing
D O s
KEEP products in dry, well ventilated area
WEAR suitable protective clothing to prevent contact with skin, eyes, nose, throat, etc.
WASH off immediately if bodily contact occurs
D O N T s POSSIBLE CONSEQUENCES
DO NOT use materials once they have become wet or
ha rdened
Materials will not hydrate fully
DO NOT leave wet materials on the skin Burns to skin
DO NOT breathe in dust Burns to throat
6B: Preparation of substrates
D O s
ENSURE all surface contaminants are removed
ENSURE substrate is sound
ENSURE there is an adequate key
CONTROL suction
D O N T s POSSIBLE CONSEQUENCES
DO NOT ignore defects in the substrate
DO NOT leave surfaces soft or dusty
Cracking and debonding of the system
As above
6C: Applicat ion
D O s
ENSURE surface is correctly prepared
MIX strictly in accordance with manufacturers instructions
MAKE sure substrate is saturated, surface dry
STOP all leaks before applying
D O N T s
DO NOT apply to dry substrates
DO NOT apply to surfaces running with water
DO NOT apply while a dehumidifier is running
POSSIBLE CONSEQUENCES
Cracking and debonding of the system
As above
Insufficient hydration
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6D: Protect ion and backfi l l ing
D O s
ENSURE system is properly cured
USE appropriate protection when backfilling
D O N T s POSSIBLE CONSEQUENCES
DO NOT force-dry the system
DO NOT allow point loading in the backfilling
Cracking and debonding
Damage to coating
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D O s
18
7 P r o p r i e t a r y c e m e n t i t i o u s m u l t i - c o a t r e n d e r s , t o p p i n g s , a n d
c o a t i n g s
7A: Storage and handl ing
D O s
FOLLOW manufacturers shelf life and general storage conditions
STORE in sealed original containers, in frost-free conditions
WEAR protective clothing, and keep a copy of the manufacturers safety sheet handy
KEEP out of reach of children, and dispose of waste and surplus correctly
RECORD batch numbers of the additive to check shelf life
STORE all ancillary materials, cement and sand correctly
D O N T s
DO NOT allow prolonged skin or eye contact
DO NOT allow materials to freeze or be subject toextreme heat, or store in an unsuitable environment
DO NOT use materials past their shelf life
DO NOT allow materials to become contaminated
POSSIBLE CONSEQUENCES
Health hazard
Material may become unusable and system ineffective
As above
Contaminated material, possible failure
7B : Preparation of substrates
STOP infiltrations of water or lower the water table before proceeding
ENSURE substrate is of sufficient structural quality and soundness
WET the substrate before applying any coating
REMOVE all surface applications such as plaster and paint
ROUGHEN or hack all the surface to produce mechanical key or use surface retarders when placing concrete
REMOVE all contamination, dust, etc.
IDENTIFY likely problems or defective areas and agree what will be done as regards repair
KEEP within prescribed temperature limits during cure
ALWAYS use the sand and cement recommended by the manufacturer
D O N T s
DO NOT apply materials to a frosted surface, or when
temperature is below 5C
POSSIBLE CONSEQUENCES
Slow rate of cure and poor surface bond
DO NOT apply to unsuitable contaminated surfaces
DO NOT apply to uncured substrates
DO NOT use beyond shelf life
DO NOT use old cement or ungraded sand
DO NOT proceed until water infiltration is stopped
DO NOT apply to substrate of inferior structural qualityand soundness
DO NOT apply to incorrectly prepared surface
DO NOT apply to thoroughly dry surface
As above
Ineffective system, substrate movement or cracking
which may reflect through render
Mix will be incorrect and the system will not function
As above
Unable to apply system correctly to surface
Cracking and failure of system
Poor bond of system to substrate
Rapid drying out of material, causing poor surface bond
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D O
D O
D O s
D O
2 0
G e o c o m p o s i t e d r a i n a g e s y s t e m s
A: Storage and handl ing
STORE as required by the manufacturer
D O N T s
DO NOT leave unused material around on site
DO NOT leave exposed to ultraviolet light for long
periods
POSSIBLE CONSEQUENCES
Damage
Decomposition of geotextile fabric
B: Preparation of substrate
ENSURE, for horizontal application, substrate is laid to falls
D O N T POSSIBLE CONSEQUENCES
DO NOT allow trafficking before backfill or concrete
oversite is placed to horizontal areas
Damage to drainage composite
C: Applicat ion and f ini shing
USE correct geocomposite type and fixings to suit substrate
INSTALL geocomposite with filter fabric to soil face
ENSURE that geocomposite filter membrane extends to wrap drainage pipe or links to a fin or other drain
ENSURE drainage outlet is to lower side of structure and drains away from building
D O N T s POSSIBLE CONSEQUENCES
DO NOT allow use of dimpled drainage core directly
against soft waterproofing membranes
DO NOT allow mechanical fixing against waterproofing
membranes
Damage to waterproofing
Damage and leakage
DO NOT allow bonding tapes to become cold or wet
DO NOT use sharp-footed reinforcement spacers
directly on membrane
Difficulty in stripping release paper or poor adhesion
Damage and leakage
D: Protect ion and backfi l l ing
USE approved backfill material and compact in layers as specified
D O N T
DO NOT use clay or chalk soil as backfill
POSSIBLE CONSEQUENCES
Clogging
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G l o s s a r y
Air dry
C o m b i n e d s y s t e m
Construction joint
D a m p
D a m p - p r o o f
Damp res i s tance
Damp-res i s tant
Dra ined cav i ty
Expansion jo int
External
w a t e r p r o o f i n g
External (reverse)
w a t e r p r o o f i n g
Free-dra in ing
High water table
Hydros ta t ic head
Hydros ta t ic
pressure
Integra l
pro tect ion
Kicker
Kicker les s
cons truct ion
When the surface humidity of a
material is equal to that of the
ambient surrounding air
Two or more waterproofing
systems used together
Joint formed in-situ, for example in
concrete, when continuity is not
possible
The condition of a material when
wetter than air dry
Impervious to moisture, not
permitting moisture to enter
The ability of a material to exclude
moisture
Having a high resistance to
moisture penetration
A continuous cavity which
intercepts and drains away
incoming water
Joint that permits relative
movement caused by expansion
and contraction due to changes of
temperature or moisture
Where the waterproofing system is
positioned and placed against theoutside face of the main structure
Where the waterproofing is
positioned outside the main
structure but placed against the
enabling works
Ground through which free water
rapidly drains away
Where the water table is above the
underside of the lowest floor level
Water pressure, expressed as an
equivalent depth of water
The water pressure exerted as a
result of a hydrostatic head
Where the structure itself provides
the necessary protection to the
passage of water
Small concrete upstand, cast above
floor level to position wall or
column formwork for the next lift
A mechanical means of retaining
formwork in position, eliminating a
kicker
Loading coat
Low-permeabi l i ty
Low water table
M e m b r a n e
Moisture
Perched water
table
Protection layer
S a n d w i c h e d
waterproof ing
Vapour check
Vapour resistance
Vapour-resistant
Variable water
table
Water
Waters top
Waterproof
Waterproof ing
s y s t e m
Water-resistant
Water vapour
A material applied to the
waterproofing membrane to enable
it to resist hydrostatic pressure
Resistant to water penetration
Where the water table is
permanently below the underside
of the lowest floor level
A material which forms acontinuous effective barrier to the
passage of water
Water in the form of vapour as well
as liquid
Where, because of insufficient
permeability of a soil, percolating
water is held above the underside
of the lowest floor level, resulting
in hydrostatic pressure
An element used to provide protection
to a waterproofing system
Where the waterproofing system is
between the two non-tied leaves of
the main structure
A continuous vapour-resistant layer
The ability of a material to resist
vapour penetration
Excludes water and has a high
resistance to vapour penetration
Where the water is occasionally
above the underside of the lowest
floor level
Water in its liquid form
A product or system, placed in-situ,
to prevent the passage of water
through a discontinuity or joint in
site-placed concrete
Impervious to water, not permitting
water to penetrate
The total method or combination of
materials used to create a
waterproof protection
Having a high resistance to water
penetration
Water in its gaseous form
R e f e r e n c e s
1. BRITISH CEMENT ASSOCIATION. Options for quality in
houses: Basements 1 - benefits, viability and costs.
Slough (now Crowthorne), British Cement
Association, 1992. 37 pp. (Ref. C/10)
2. BRITISH CEMENT ASSOCIATION. Basemen t waterproofing:
Desi gn gu id e. Crowthorne, 1994. 20 pp. (Ref. 48.058).
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BASEMENT WATERPROOFING: SITE GUIDE
BRITISH CEMENT ASSOCIATION PUBLICATION 48.059
British Cement Association
British
StructuralWaterproofingAssociation