When working with adhesive and other process materials, the handling guidelines of the adhesive manufacturers and the relevant legislation and standards for the country concerned must be complied with.
These recommendations prove additional product-specific information, compiled to the best of our knowledge and on the basis of practical experience and tests. If in doubt, users are advised to perform their own adhesive tests. Since proper handling and processing of the products is beyond our sphere of influence an control, we cannot accept any guarantee for the installation results obtained. Our warranty and liability only apply to the extent stipulated in our Terms of Delivery and Payment.
The following details should be known to the installation company, or the information
obtained, when the offer is issued:
- Are there builder's hoists or lifts that can be used?
- Can storage space or working areas be partitioned off and locked?
- Can water and electricity supplies be shared?
- Planning of stages of work or interruptions?
- Particular obstacles: e.g. working in rooms being used by other
workmen, working at unusually high temperatures, working in rooms with poor ventilation, etc.?
- Type and condition of subfloor, any priming or levelling required?
- Is there a screed with underfloor heating?
- Any unusual requirements/special duties for the flooring, e.g. castor-wheeled office
chairs, truck traffic, exposure to chemicals, insulation against electricity,
electrical conductivity, etc.?
- Shape of connections to adjacent parts of the building?
- Type and number of openings, apertures for pipes, etc.?
- Any floor shape other than rectangular, oblique-angled or round surfaces, stairs, etc.?
- Invoicing according to side measurement or accurately marked drawing?
- Joint-sealing of sheets or tiles in conjunction with skirtings?
- Is a damp course built into areas with no cellars below, or above rooms with high temperatures
(e.g. boiler rooms, laundries, etc.)?
When the order has been placed, remember the following:
- Check the room dimensions on site - it may depend on only a few centimetres whether entire
sheets or tiles are sufficient (cutting waste is costly).
- Selection and provision of the process materials required (e.g. primers, levelling
compound, adhesives, jointing compound, hot welding rod, profiles).
Before starting installation
The installation company must check the subfloor to ascertain whether it is suitable for
having floorcoverings installed on it. Any reservations must be presented in writing if any
of the following are found:
- Very uneven subfloor
- Cracks in the subfloor surface
- Insufficiently dry subfloor
- Insufficiently firm subfolders surface
- Surface of the subfloor too porous or too rough
- Soiled surface of the subfloor, e.g. with oil, wax, paint or lacquer residues
- Incorrect height of subfloor in relation to adjacent parts of the building
- Unsuitable temperature and ventilation conditions in the room.
Testing/correction of defects/preparation
- Very uneven subfloor
A surveyor's rod and a spirit level are used for testing purposes.
The permissible tolerances should be drawn from the national
standards. The following tolerances are permitted in Germany.
Tolerances in mm at a distance between measuring points of:
| up to 0.1 m |
1.0 m |
4.0 m |
10.0 m |
15.0 m |
| 1 mm |
3 mm |
9 mm |
12 mm |
15 mm |
The screed must not be walked on for at least 3 days after completion of
surface treatment, and even then it must not be subjected to the load of
building materials, etc. Generally, the screed cannot be stressed until 21 days
have elapsed.
Small ripples will appear in the surface of the floorcovering after it has
been installed and must therefore be the subject of a complaint beforehand.
The subfloor must be smoothed out with levelling compounds or filling compounds
if it is very uneven. A very uneven surface is generally to be expected in stone
or ceramic floors. It may be necessary to repeat the levelling procedure
several times.
- Cracks in the surface
Hairline or fine cracks (width - 3.0 mm) must be distinguished from larger ones.
If the hairline cracks affect only the surface of the screed (no vertical movement
of the screed sections), they can be ignored.
Larger cracks (0.3 mm or wider)
go right through the entire screed layer, and this can cause vertical movement of
the screed sections when subjected to strains, especially with floating screeds.
Possible reasons for this are, for instance, insufficient or uneven thickness,
drying too quickly, insufficient space away from edges at recesses, protrusions,
supports, incorrect composition of the screed mortar, etc.
Diagram 1
Crack formation in a solid section of a building. The company installing the screed
had not made a joint from A to A. It is possible to remove the cracks in the
screed.
Cracks of this type must be properly repaired/remedied in accordance with the following
diagrams.(This is usually part of the screed installer's job.)
Diagram 2
Repair of cracks in screed by means of two-component resin substances and screed repair
clamps.
Diagram 3
Situation as above in diagram 2, but in cross-section
The cracks repaired as shown in the diagram must be strewn with quartz sand when fresh
in order to ensure bonding with the levelling compound.
- Insufficiently dry subfloor
Excessive moisture is a frequent cause of damage. The most reliable method for carrying
out this important measurement is to use the tried-and-tested CM meter (moisture-gas
pressure gauge).
Manufacturer: Riedel-De Haen AG, Seelze near Hannover.
The following is an overview of equilibrium moisture for the most important subfloors
in the moderate climatic zone:
| Type of subfloor |
Permissible moisture content
(domestic moisture)
measured with CM meter |
Cement screed
Anhydrite and plaster screed
Mastic asphalt screed
Chipboard
Concrete |
2.0 CM-%
<0.5 CM-%
- not applicable -
4.0 - 9.0 CM-%
3.5 - 5.0 CM-% |
If humidity is permanently high, the equilibrium moisture of the subfloors will
increase, so that installation can also take place if the moisture content of the
screed is higher (consult adhesive manufacturer). Please note that the subfloors
require a longer drying time.
Testing with electrical instruments is also possible. Measurements must be taken at the
dampest place, e.g. in a poorly ventilated corner of the room or - if this is known -
at points where the screed is relatively thick.
Drying time for a subfloor is difficult to predict, as it is influenced by a number of
factors, such as thickness of the screed, temperature, ventilation, humidity.
Indications can be taken from the age of individual sections, assuming that the
supporting base (e.g. concrete layer) was dry enough when the screed was applied. (It
is absolutely essential to install a plastic film which has been swell-welded at the
seams in order to prevent the migration of residual moisture from the concrete to the
screed.)
- Insufficiently firm surfaces
The installer must check the subfloor surface's hardness to see whether levelling
compounds, primers, or adhesives are firmly bonding with the subfloor. A reliable method to test the firmness of the
subfloor is done by using a sharp chisel, steel nail or screw
driver.
If sparks are
produced when the surface is scratched rapidly, the hardness is very good.
If the subfloor is to soft and too flaky, a complaint
must be made to the contractor.
In such
cases, a decision will have to be taken as it is possible to remove the
soft layer mechanically.
Any grout layers must be removed by sanding them off, brushing them off with wire
brushes, by the Blastrac method, or similar.
- Surface too porous or to rough
Surfaces of this type can be recognised and assessed only by visual inspection.
Excessive porosity of the screed will impair firm bonding with levelling compounds and
adhesives. Excessive absorbency would mean that the mixing water of the levelling
compound, for instance, is absorbed too quickly. If this is the case, it is absolutely
essential to apply a primer.
Sometimes, mechanical damage caused by friction from traffic makes additional priming
and levelling necessary in these areas.
- Soiled surfaces
All sorts of soiling (e.g. oil, grease, wax, paint and lacquer residues, plaster, dust,
etc.) prevent proper adhesion of primers, levelling compounds and adhesives to the
subfloor; this is why they have to be mechanically detached by suitable means from the
surface and the detached bits removed by sweeping or with a vacuum cleaner. After that,
mill out and/or repair subfloors as necessary.
Vacuum-cleaning is more effective than sweeping.
- Incorrect height of subfloor
The floorcovering installer is not responsible for remedying any incorrect height of
the subfloor. It is his duty, however, to check whether after installation of the
floorcovering there will be differences in height between adjacent sections of the
building and the room where the flooring has been installed (e.g. between rooms and
corridors).
Attention must also be paid to the heights of adjacent ceramic tiles, parquet flooring,
door-stops, etc. Subfloors that are higher than other adjacent floorcoverings should
also be the subject of an objection; i.e. the customer should be told about this kind of
concern before starting floorcovering installation work.
- Unsuitable temperature and ventilation conditions
The rule-of-thumb is that resilient floorcoverings should be installed at approximately
the same temperature they will be exposed to later during use.
Floorcovering should not be installed at a subfloor temperature below 15 °C (60 °F) and
a relative humidity of more than 75 %, as this kind of indoor climate can have adverse
effects on the flooring itself and its processing.
(For example, low temperatures lead to a considerable increase in the setting time and
reaction time of adhesives and levelling compounds; the drying time for primers and
levelling compounds and the airing time for adhesives are likewise increased by high
humidity.)
The corresponding details of times given by the manufacturers of adhesives are based on
a temperature of 20 °C (68 °F) and 50 % relative humidity as a general rule. This is
why floor temperature and humidity measurements are helpful.
This form is intended as a working aid and record for subsequent documentation of the tests you
have carried out.
Subfloor testing
Testing report of the floorcovering installer
Customer: ________________________________________
Architect: _______________________________________
Project/Building site :___________________________
Start of work: ___________________________________
Planned completion: ______________________________
A) Type of subfloor: _____________________________
B) Very uneven subfloor: _________________________yes/no
C) Tension or settling cracks visible: ___________yes/no
D) Maximum permissible equilibrium moisture
of this __________screed: ________CM-%
E) Moisture measurement of this screed carried out
on __________with a ___________instrument _________CM-%
F) Floorcovering work possible on this basis? __________yes/no
G) Are rooms without cellars bellow to be covered?
If yes, is damp coursing present? _________________yes/no
H) Hardness? _______________________________good/moderate/poor
I) Are there porous, rough or crumbling patches? _____yes/no
J) Is the height flush with adjoining sections of the building? ________yes/no
K) Is soiling of the subfloor surface present? _________________________ yes/no
If so, what kind? _____________________________________
L) What is the indoor climate like?
Room temperature: _________________________________°C/°F
Floor temperature: ________________________________°C/°F
Relative humidity: ________________________________°C/°F
M) Special peculiarities: ___________________________________
Date:
Signature of site manager:
Signature of flooring installer:
Subfloors/Properties/Measures
The following subfloors are found in practice:
- Cement screeds
- Anhydrite or plaster screeds
- Mastic asphalt (vacuum asphalt)
- Industrial screeds
- Concrete
- Chipboard and plywood with tongue-and-groove
- Resin-impregnated marine plywood
- Artificial or natural stone, ceramic tile floorings
- Coatings and paint
- Screeds and underfloor heating
Subfloors to be covered with a rubber flooring (almost vapour-proof) require sealing (insulation) against rising damp if there is no cellar underneath. Water-repellent concrete, crawl spaces or similar are not sufficient to prevent the migration of damp into the subfloor.
A damp course will also be required above rooms with high temperatures and/or humidity (e.g. boiler rooms, commercial kitchens, bakeries, laundries, etc.) or if hot water pipes with inadequate thermal insulation run underneath the ceiling.
Expansion joints in the building must not be closed by the flooring. If it is laid and stuck across expansion joints in the building, it may tear, as it is fixed firmly in place and cannot "work" with the movements of the building. Expansion joints for the building are found, as a rule, in large areas. Expansion joints which do not run through the whole of the building (e.g. construction joints in the screed), but are designed merely to absorb tension during setting, are now what is meant here. The contractor will, however, be well advised to consult with the customer concerning the connection to expansion joints.
- Cement screeds
This is the most common type in building construction. Due to the shrinkage tension occurring during
the setting phase, separation joints (dummy joints) are laid out during insertion about 6 m away from
each other and at recesses or protrusions.
In order to get a sufficient subfloor all joints must be filled and properly fixed together by using a
epoxy resin and metal pins. Cement screeds are absorbent. Dispersion adhesives may be used.
Plaster or anhydrite screeds
Attention must be paid to the low permissible domestic moisture of <0.5 %. These screeds can be
applied over large surface areas without separation joints. Moisture entering and remaining in the
screed after application will damage the screed.
Generally speaking, these screeds must be sanded, brushed, vacuumed and treated with primers. In such a
case, the reduced absorbency as a result of the primer has to be compensated for by the appropriate
thickness of levelling (not less than 2 mm) if dispersion adhesives are used. Before fixing, the
filling must be completely dry (drying time approx. 24 hours).
Mastic asphalt (vacuum asphalt)
This is applied in a hot, molten condition (200 - 220 °C), smoothed and rubbed over with fine quartz
sand. If applied properly, mastic asphalt can be used to cover large surfaces without cracks. It can be
walked on as soon as it is cold. Mastic asphalt has no pores, and when installed in two layers acts as
a damp-proof course in building construction.
If a dispersion adhesive is used, mastic asphalt must be levelled with a minimum of 2 mm layer
thickness.
If contact adhesive is used, a levelling compound must also be applied, in order to avoid direct
contact between the mastic asphalt and the solvents contained in the adhesive.
If reaction adhesive is used, only polyurethane adhesive may be used on mastic asphalt.
Industrial screeds
These are primarily for heavy-duty industrial use with transportation loads. Screeds of this type
exhibit high surface density and have few pores, so that it is difficult to obtain good adhesion.
Subfloors of this type have to be roughened (e.g. by sanding, brushing with wire brushes, sandblasting,
Blastrac method), primed and levelled. To find out how much (if any) preparatory work will be
necessary, it is essential to fix test strips. (Technical advice should be sought from the suppliers of
levelling compounds and adhesives.)
If there is no damp course to insulate against rising damp, it is advisable to exclude from your
guarantee any damage that may result from this.
Concrete
The moisture content of concrete subfloors can be determined only inadequately with a CM meter. If you
nevertheless decide to use it, you must take material from the entire thickness of the substrate.
The most reliable method for determining the moisture content is drying in a heating cabinet; however,
this is only possible in a laboratory.
If there are excessive amounts of residual moisture, this can be sealed on the surface using special
two-component primers. You must consult the supplier concerned.
Pretreatment:
Subfloors of this type have to be roughened (e.g. by sanding, brushing with wire brushes, sandblasting,
Blastrac method), primed an levelled. To find out how much (if any) preparatory work will be necessary,
it is essential to fix test strips. (Technical advice should be sought from the suppliers of levelling
compounds and adhesives.)
Chipboard and plywood with tongue-and-groove
Fairly large surfaces can be installed without joints by gluing the tongue into the groove. Generally,
only the butt joints between the boards are levelled or sanded. Whether or not priming is necessary
will depend on the surface quality of the boards concerned.
If the joints are not glued, they will show later on the surface of the flooring.
Marine plywood
The same applies here as for Point 6. These types of plywood, sometimes impregnated with synthetic
resin, make the use of dispersion adhesives impossible. Only through adhesive testing can the type of
preparatory treatment required (sanding, priming) be determined.
Artificial or natural stone, ceramic tile floorings
Subfloors of this type are non-absorbent. Preparatory treatment, therefore, as for Section D/Point 4 -
industrial screeds. All soiling (e.g. grease, waxes, soap, etc.) must be thoroughly removed
mechanically and with detergents, especially if floors like this have already been in use for some
time. Any loose tiles must be re-fixed.
Coatings and paint
These are usually very low in pores or have none. Whether preparatory treatment is necessary will have
to be investigated as described in Section D/Points 4 and 8. Any flaky parts must be scrupulously
removed. As the composition or bonding agent in such coatings is mostly unknown, trial strips with
different adhesives will have to be tested, while simultaneously advice is sought from the adhesive
manufacturer.
Screeds with underfloor heating
This is only possible with cement and anhydrite screeds.
Depending on the system involved, this kind of screed is 45 - 65 mm thick. Testing the moisture of the subfloor using the CM meter
(moisture-gas pressure gauge) is always possible if the
installer of the screed marked the measuring points. This is the
only way to avoid damaging of the heating pipes while the test
samples are taken from the screed. If there are no marks, a
complaint must be made to the contractor.
Drying out can only be
done by a suitable period of drying through heating.
For this reason, the screed must be heated up before installing the flooring. Heating of the screed
should be performed no earlier than 21 days after application of the screed.
Beginning with a feed temperature of 21° C the screed should
be heated up in steps of 10° C every day until the maximum
feed temperature is reached. After 11 days at the maximum
temperature, it should be reduced in steps of 10° C per day
down to a temperature of 20° C.
This temperature must remain constant for 3 days after the floorcoverings have been installed or the
surface treatment applied. The temperature of the subfloor should not exceed 28° C
over a prolonged period of time.
Process materials
Primers, levelling compounds, adhesives
Some important terminology for application:
The most important terms are explained below because of their special significance for correct and
thus damage-free fixing and processing of textile and resilient floorcoverings:
Airing time
The time required by certain types of adhesives for the carrier contained in them (solvent or
water) to evaporate.
Embedding time (open time)
The time in which the floorcovering is laid into the adhesive bed and rubbed into place.
Potlife
The time between mixing the reaction adhesives or levelling compounds in a bowl and the incipient
hardening. If this time is exceeded, hardening will already begin in the mixing bowl, so that the
adhesive or levelling compound will be unworkable.
Drying time
The time is takes for all the volatile contents in primers and levelling compounds (solvents or
water) to evaporate.
Bonding time
This is the time by which the various adhesives have fully bonded and the installed floorcovering
can begin to be used normally.
- Primers
These are available as aqueous synthetic resin dispersions, as synthetic resin solutions with flammable
solvents and as two-component material based on PUR and epoxy resin EP. Primers must be completely dry
before the application of levelling compounds and adhesives.
Primers are required as an adhesion
link, to give a hard surface on worn-out screeds, and for dust-laying on porous subfloors.
- Base coat = impregnation
In the case of screeds with a dusty surface, low-viscosity primers must be used for
applying the base coat, which must work down to a sufficient depth.
Important: The base coat must not form a film.
Adhesion link = film-forming primer
On a dispersion basis; enables smooth, impermeable, non-absorbent subfloors to be
firmly bonded to the levelling compound.
Two-component products
Can be used on absorbent and non-absorbent subfloors. The primer must be strewn with
quartz sand for proper adhesion of levelling compounds or reaction adhesives.
Levelling compounds
Levelling compounds are supplied in powder form and mixed with water for application. They contain
cement and synthetic resins as bonding agents.
It is important to use the amount of water specified by the manufacturer for mixing. Too much or too
little water content impairs the hardness, as is also the case if the layers are too thin. The layer
thickness required for castor-wheeled traffic is 2 mm. This layer thickness is also necessary on
non-absorbent subfloors (see Section D) on which dispersion adhesives are used.
Levelling compounds are used to smooth the surface (roughness or ripples) and to eliminate slight
differences in height.
Adhesives
3.1 Reaction adhesives (two-component adhesives)
Two-component adhesives based on epoxy resin EP or polyurethane PUR are used for fixing rubber
floorings. These adhesives bond only by chemical reaction, which sets in after the two components are
mixed together. Once the adhesive has been mixed, it must be applied to the subfloor with a serrated
blade during its potlife. The flooring must be laid during the open time and pressed down into
position. Initial adhesion is minimal, so that positioning of the flooring is possible during the
initial phase.
Depending on the temperature, bonding time is 8 - 12 hours. High or low temperatures shorten or
lengthen the potlife, embedding time and bonding time. Two-component adhesives when completely bonded
are water-insoluble and moisture-resistant.
If wheeled traffic is anticipated, we recommend a bonding time of up to 7 days.
3.2 Dispersion adhesive (one-sided adhesive)
Dispersion adhesives usually consist of acrylic resins dispersed in water. The adhesive is applied to
the subfloor with a serrated blade.
For fixing rubber floorings, only top-quality dispersion adhesives are suitable.
The flooring must be embedded in the freshly applied adhesive, making sure that the entire back of the
floorcovering is completely covered with adhesive.
Bonding is brought about by the evaporation of the water content of about 20 - 30 %. For this reason,
absorbent subfloors or subfloors treated with absorbent levelling layers are required. Bonding
generally takes 2 - 3 days, but this time may extend to several days under adverse conditions.
Stress-free levelling compounds may exhibit reduced absorbency. This must be taken into account when
using dispersion adhesive by modifying the point in time for embedding.
The water content in the dispersion adhesive must be largely absorbed by the air.
3.3 Contact adhesives (synthetic rubber adhesives)
Contact adhesives consist of a mixture of synthetic rubber and synthetic resin dissolved in flammable
solvents. The solvents are readily flammable. Affix warning signs. The adhesive is applied to
both surfaces, the back of the flooring and the subfloor. During the airing time required, about 90 %
of the solvents evaporate. Once the flooring is embedded, it can no longer be shifted. After pressure
has been applied, good adhesion is attained at once. The flooring can be walked on immediately.
Final hardness is reached after 2 - 3 days.
Material check routine
You must check the flooring for colour and batch uniformity (control number on packaging label).
Notice of defects or material replacement is only possible if the material has not yet been installed.
Additional costs will not be reimbursed.
At the time of installation, noraplan® and norament® floorcoverings must have the same
temperature as the subfloor. In winter, therefore, the floorcoverings have to be stored for some days
at installation temperature.
On their back noraplan® and norament® floorings are marked by arrows. Always install sheets
or tiles with the arrows pointing in the same direction.
norament® tiles with minor surface flaws are marked like this: At the point marked, these tiles
have such flaws up to the third row of pastilles at the most, and can be used as cutting tiles for
border areas.
Floor protection system
Sand, stone, chippings, sharp objects can cause irreparable damage to flexible floorcovering
materials. Particularly during the construction phase, the floorcovering is often damaged
by other building trades. It is therefore essential to effectively protect the flooring
with suitable materials during the construction phase. Rele offers a suitable
floor protection system that can be removed after use and then reused.
For more information please visit www.rele-systems.com.
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