1. Waterproofing

Can I also apply AQUAFIN-2K/M-PLUS mechanically.

Yes, e.g. with the HighPump-M8 peristaltic pump or with the screw-feed pumps HighPump-small, HighPump-Pictor or PFT-Swing. We recommend a nozzle size of 4.5 to 6.0 mm. Further information can be obtained from TZI-43 "Machine applied bitumen products, slurries and injection products" or via HTG HIGH TECH Germany GmbH, Berlin, or from PFT-Putztechnik,

Are mineral-based waterproof membranes such as e.g. AQUAFIN-2K/M PLUS covered by standards?

The AQUAFIN series of mineral-based waterproof membranes have proved themselves for decades in practice. Since 07-2017, two component mineral-based waterproof membranes like e.g. AQUAFIN-2K/M-PLUS or AQUAFIN-RS300 have been approved as stand-alone waterproof membranes in new constructions in accordance with DIN 18533 (waterproofing of building components in contact with the ground). The waterproof membranes are used for water penetration classes W1-E (ground moisture and non-pressing water), W1.2-E (ground moisture and non-pressing water with drainage) and W4-E splashed water and ground moisture at the building skirt zone as well as capillary rising water in and beneath walls).
Retrospectively applied waterproof membranes to buildings are not currently regulated by a standard. In these cases, assistance is offered in the form of appropriate data sheets such as e.g. the WTA technical sheet 4/6 (retrospective application of waterproof membranes to building components in contact with the ground) or the technical sheets from the German construction chemical industry.
In contrast, waterproofing of containers such as swimming pools or process water containers is regulated by DIN 18535 (waterproofing containers and pool tanks). DIN 18535 differentiates between non-combined constructions e.g. coating to a process water container or waterproofing in combination with tiles and slabs such as e.g. showers or swimming pools. The products AQUAFIN-2K/M-PLUS or AQUAFIN-RS300 are suitable up to water penetration class W2-B (fill depth < 10 m).

Why is it necessary to use the ASO-Systemvlies-02 over thick bitumen coatings?

ASO-Systemvlies-02 is a protective measure.
It is recommended for:
* Protection against damage during the reaction/drying phase.
* Prohibits rapid skin formation on the fresh material and consequently reduces the reaction/drying time.
* Protects against shifting or slipping drainage or insulation boards.

The surface of the tanking material is protected immediately after application. Following protective layers e.g. perimeter insulation are not bonded directly to the coating. The ASO-Systemvlies-02 forms a slip layer that prohibits damage to the tanking material from sliding slabs during back filling the excavation.

What is a waterproof concrete tank (Weiße Wanne)?

A waterproof concrete tank (weiße Wanne) is concerned with a building made from waterproof concrete. According to the German committee for reinforced concrete, these are either partially or completely in contact with the ground. The concrete, without additional measures, fulfills the load-bearing and waterproofing functions. Joints and penetrations are waterproofed using suitable means as necessary. The construction and planning of concrete structures using waterproof concrete require particular care and must be carried out in conjunction with current regulations. In addition to the consistency of the concrete, the formation of joints and the avoidance of cracks through movement calculations is of particular significance.

What are the requirements for waterproofing a substrate?

For example the following substrates are suitable for waterproofing: brickwork and sand-lime brickwork, aerated concrete blocks, solid lightweight concrete or concrete blocks, mixed masonry work, concrete or reinforced concrete and renders. All the named substrates must be clean, free from grease and dust and free from all other adhesion inhibiting materials. The bond between waterproofing material and substrate must not be negatively influenced.

What is the function of construction waterproofing?

The waterproofing of structures in direct contact with the ground is to permanently protect a building from moisture and to render the internal space more significantly useful. The waterproofing products and system components must be compatible with one another and complement one another. The waterproofing of building foundations / aprons as well as wall penetrations (pipes and cables) and the transitional area between vertical and horizontal areas must be carried out in such a way as to ensure the secure and permanent protection against moisture.

Which products / materials are approved for waterproofing to DIN 18195?

The following materials are regulated to DIN 18195, part 2: Hot applied adhesives and paint on roofing materials, asphalt mastics and poured asphalt, bitumen and polymer bitumen sheet membranes, synthetic and elastomer sheet membranes as well as polymer modified high build bitumen coatings e.g. COMBIFLEX-EL (Tabelle 1-6) (tables 1 - 6). Furthermore mineral-based, crack-bridging and non crack-bridging waterproof slurries (MDS - table 7), e.g. AQUAFIN-RS300 as well as liquid plastics for construction waterproofing (FLK - table 9). Materials described in tables 1 - 6 may be used for waterproofing wet duty exposure in DIN 18195 parts 4 - 6. The materials described in tables 7 and 9 are approved to date only for wet duty exposure to DIN 18195 part 7.

What are the fundamental conditions which determine the wet duty exposure class to DIN 18195, which act on structures in contact with the ground?

The measurement of the water table, the impermeability of the infilled earth and the incorporation of drainage defines the wet duty exposure class to DIN 18195. Above the measured water table relates to wet duty exposure classes "ground moisture" and "seepage water (run-off water)", if the backfill material is highly permeable. The incidental water exerts no hydrostatic pressure on the waterproof membrane. However, if the earth is of low permeability, it must be assumed that there will be, intermittently, water exerting hydrostatic pressure and one must reckon with standing water or even water under pressure (greatest assumable water table ≥ 30 cm below the top edge of the foundation slab).
This means that the water table measurement, the backfill material and the planned drainage as necessary must be incorporated at conception, planning and implementation of any waterproofing measures.

In a new-build situation, which regulation describes the type and implementation of waterproofing in areas in contact with the ground, as well as horizontal areas or those with shallow gradients?

DIN 18195 is the accountable regulation for new-build. In part 2 of this standard, the so-called "stock standard", the materials possible for use in waterproofing are described. Part 4 explains the wet duty conditions for "ground moisture" and "non standing seepage water" for structures in contact with the ground. Part 5 of the standard describes waterproofing of ceiling areas against water not under pressure and in wet rooms. Part 6 of DIN 18915 sorts out waterproofing against water under negative hydrostatic pressure and standing seepage water. The "Polymer modified bitumen reglulations" of the German Construction Chemical Industry offers assistance here.

Which regulation describes the type and methodology of structural waterproofing?

DIN 18195 is split into individual standard parts, which in summary regulate an application for all waterproofing materials, such as e.g. connections and closures (DIN18195-8). Since July 2018 only the definitions for structural waterproofing are regulated in DIN 18195. The standard parts have been condensed into applications related to building structures. The individual parts of the standard are:
DIN 18531 – Waterproofing of roofs, which are utilized
DIN 18532 – Waterproofing of areas subjected to vehicular traffic
DIN 18533 – Waterproofing of structures in contact with the ground
DIN 18534 – Waterproofing of internal rooms
DIN 18535 – Waterproofing of containers and pools
Each standard consists of a general part, in which the requirements of the building structure are explained. In other parts, the requirements of each particular material to be applied and their applications are regulated. Therefore e.g. DIN 18533 (waterproofing of structures in contact with the ground) is made up of the following parts:
Part 1: Requirements, planning and implementation principles
Part 2: Waterproofing with sheet form waterproofing materials such as bitumen sheet membranes or polymer/elastomer sheet membranes
Part 3: Waterproofing with liquid applied membranes such as e.g. waterproofing slurries, high build bitumen coatings, reaction resins or polymeric liquids

Which primer do I use beneath COMBIDIC-1K

ASOL-FE diluted 1:5 with water. Allow the primer to dry before applying COMBIDIC-1K.

Which water penetration classes are there in accordance with DIN 18533 and how are these assessed? (Replacement for "Which boundary conditions determine the exposure level….“)

Of significance, when exposed to water, is the permeability to water of the ground, the filling material, the use of drainage as well as the measurement of the water level. With the introduction of DIN 18533, when dealing with pressing water the planner needs not only to make allowances for the highest level of the ground water (HGW) but also, dependent on the environment, the highest measured high water level (HHW).
Definition of water penetration classes:
- Ground type with high permeability to water (k > 10 -4 m/s) corresponds to "Ground moisture and non-pressing water (W1-E)".
- Ground type with low permeability to water (k < 10 -4 m/s) as well as the incorporation of drainage with filling material capable of percolation corresponds to "Ground moisture and non-pressing water with drainage (W1.2-E)".
- For ground types with low permeability (k < 10 -4 m/s) without additional measures, the water penetration class “Pressing water (W2-E)" is in effect. These we differentiate as “moderate water exposure and construction depths < 3 m (W2.1-E)" and "high water exposure with construction depths > 3 m (W2.2-E)".
- Water penetration to horizontal areas (e.g. non-utilized roofs of subterranean garages) with a max. depth of accumulation of 10 cm corresponds to "Non-pressing water to earth covered roofs (W3-E)".
- Penetration through splashed/sprayed water or rising moisture is designated as "Water penetration class splashed water and ground moisture at the building skirt as well as capillary water in and beneath walls (W4-E)".

2. Repair of buildings

At which thickness must restoration plasters be applied?

The minimum thickness of THERMOPAL restoration plasters is 20 mm dependent on the salt levels in the substrate. This can be applied in one operation.
With high to medium levels of salting, apply the restoration plaster in two layers from a minimum thickness between 25 and max. 40 mm.
From experience, allow a waiting time of one day per millimetre in-between plaster layers.

Can I also apply THERMOPAL-SR44 (white or grey) mechanically.

Yes e.g. with the PFT G4. The necessary features can be extracted from the equipment schedule THERMOPAL-SR44.

Which bonding primer is necessary for a restoration plaster?

The splatterdash mortar THERMOPAL-SP is used as a bonding primer for restoration plasters THERMOPAL-SR24, THERMOPAL-SR44, THERMOPAL-ULTRA as well as THERMOPAL-GP11. As a rule this is applied beneath restoration plasters as half cover as nodules (coverage rate < 50%).
The splatterdash coat is only applied as full cover beneath restoration plasters if the substrate was previously coated with e.g. a waterproofing slurry.
The mix water for THERMOPAL-SP can be modified with the hardening and bonding agent ASOPLAST-MZ for very absorbent or very weakly absorbent substrates.
THERMOPAL-SP can also be used as a splatterdash coat for conventional cement or lime-cement mortars.

What differences are there with restoration plasters?

The SCHOMBURG restoration plasters THERMOPAL-GP11, THERMOPAL-SR24, THERMOPAL-SR44 and THERMOPAL-ULTRA are WTA certified products (WTA data sheet 2-9-04/D).
Restoration plasters to WTA guidelines have salt storing and hydrophobic properties and increased water vapour transmission whilst at the same time having reduced capillary conductivity.
THERMOPAL-SR44 is characterised by an extremely low consumption (consumption: 7.5 kg/m²/cm).
THERMOPAL-ULTRA possesses the advantage of a rapid cure which makes the early post-treatment of the plaster surface possible (e.g. rubbing down or using a grid float).
The areas of application remain basically the same for SCHOMBURG restoration plasters.

How can restoration plasters have coloured designs?

Use highly vapour permeable paints such as e.g. silcate paints on restoration plasters in order not to impair the effectiveness of the restoration plaster system. This is also applicable for further build-up such as e.g. fine or decorative plasters.
As renovated areas with restoration plasters are frequently coated with a white paint, SCHOMBURG offers THERMOPAL-SR44-white, whereby the usual paint can be omitted.

Why are restoration plasters used?

Restoration plasters are used for producing diffusion permeable and dry plaster surfaces onto damp and/or salt laden internal and external walls.
Restoration plasters have a relatively high air pocket content in contrast to other plasters, which is required to allow structurally damaging salts to crystallize out in the plaster without damaging the plaster.

3. Screeds

Can SCHOMBURG special screeds be used in exterior areas?

Externally screeds prepared with ASO-EZ2-Plus, ASO-EZ4-Plus, ASO-EZ6-Plus and ASO-EZ-LIGHT-Plus can be installed if they are covered with a suitable SCHOMBURG bonded waterproof membrane.

Can special SCHOMBURG screeds be applied mechanically?

Yes, ASO-EZ2-Plus, ASO-EZ4-Plus, ASO-EZ6-Plus and ASO-EZ-LIGHT-Plus can be applied mechanically.
To mix them we recommend the Brinkmann Screed-boy with a 65 mm pipe diameter or other conventional screed mixers PFT. Putzmeister Mixocret or similar. Check the water addition and avoid excess water.

Can SCHOMBURG special screeds be used in wet duty areas?

In wet duty areas of class A0, A, B0, C in accordance with the ZDB data sheet, screeds with ASO-EZ2-Plus, ASO-EZ4-Plus, ASO-EZ6-Plus and ASO-EZ-LIGHT-Plus can be installed, if covered with a suitable SCHOMBURG bonded waterproof membrane.
In swimming pool tanks, wet duty class B, in accordance with the ZDB data sheet "Bonded waterproofing systems", screeds with ASO-EZ2-Plus or ASO-EZ4-Plus can be installed if covered with a suitable SCHOMBURG bonded waterproof membrane.

Does a surface sealing on a freshly layed screed flooring require mechanical preparation (ie: shotblasting etc)?

The substrate must be prepared using suitable methods, so that an open-pored surface suitable to receive coatings is achieved. All adhesion inhibiting substances must be removed. This can be carried out by blast cleaning techniques, planing or similar methods.

When can special SCHOMBURG screeds be trafficked / put into service, after laying?

ASO-EZ2-Plus: foot traffic after approx. 6 hours; ready to receive tiles after 4 days; full service conditions after approx. 7 days.
ASO-EZ4-Plus: foot traffic after approx. 6 hours; ready to receive tiles after 4 days; full service conditions after approx. 7 days.
ASO-EZ6-Plus: foot traffic after approx. 4 hours; ready to receive tiles after 1 day; full service conditions after approx. 7 days.
ASO-EZ-LIGHT-Plus: foot traffic after approx. 48 hours; ready to receive tiles after 28 days; full service conditions after approx. 28 days.

Which screed should I ideally use on to a wooden floor over joists?

A wooden floor over joists can be negatively influenced by the installation of e.g. a cement-based screed both statically (through the weight of the screed) as well as by the water content of the screed. Frequently the required height does not exist e.g. at doorways, so that such materials cannot be incorporated. Therefore for such backgrounds we recommend the lightweight epoxy resin screed ASODUR-LE which due to its low weight per area as well as its thin application to be suitable for the critical requirements.

Which bonding slurry should I use to bond cement-based screeds?

Either ASOCRET-HB-flex or alternatively a slurry coat made from the screed mortar and ASOPLAST-MZ dilued 1:1 with water.

Which special SCHOMBURG screeds are suitable for underfloor heating?

ASO-EZ2-Plus, ASO-EZ4-Plus and ASO-EZ6-Plus are suitable for underfloor heating. These special screeds are ready to be commissioned after only 3 days to recognised regulations.

How is it best to dry a screed?

All installed screeds must be protected from draughts. In the first week after laying the screed, only the windows on the gable end should be opened a crack. Afterwards it is recommended that the air is completely exchanged (completely open the windows) for 1.5 hours, three to four times a day.

4. Tile laying

What do I have to watch out for when installing rectified tiles?

With rectified tiles, the edges are additionally abraded during manufacture so that the edges are at a 90° angle to the surface. As a rule they are large format tiles whose installation is a special construction, which needs to be notified to the client, due to edge lengths greater than 60 cm, Abrasion gives right angled edges so that "lipping" especially stands out. Therefore as a rule, it is recommended that the substrate is levelled to a thickness of 5-8 mm, even if the substrate meets the flatness requirements given in DIN 18202. Dependent on the substrate there are the levelling compounds SOLOPLAN-30 or SOLOPLAN-30-CA available. As the large format tiles are very dimensionally exact, it is possible to install rectified tiles with very narrow joints. Hence the grout quantity and joint width are relatively small so that dimensional changes in the substrate can only be accommodated to a limited extent. It is therefore recommended when installing to use a deformable/highly deformable adhesive -Additional technical information No. 21-, in combination with a deeper notched trowel as stress relieving measures. As a rule, grouting is carried out with the mineral-based CRISTALLFUGE-PLUS with rapid crystalline water binding. An optimum solution is offered by CRISTALLFUGE-EPOX, which due to its resin base allows considerably higher stress relief when compared with mineral-based grouts. In addition CRISTALLFUGE-EPOX offers a particular colour range with long lasting colour intensity.

A cement-based screed must be levelled before tiling - what do you recommend?

If cement-based screeds need to be levelled then the fluid smoothing compound SOLOPLAN-30 can be used. This is used at a thickness from 3 - 30 mm to smooth, patch and level. For thicknesses ≤ 20 mm, prime concrete and cement-based screeds with ASO-Unigrund-GE. For thicknesses > 20 mm prime substrates with ASODUR-GBM and blind with 0.5 - 1.0 mm quartz sand. Perimeter, bay, structural joints and movement joints are to be carried through or inserted into the planned locations and stopped with a suitable medium e.g. edge insulation strip RD-SK50. At thicknesses ≤ 20 mm SOLOPLAN-30 can be tiled after 16 hours.

Is there a suitable tile adhesive to fix tiles to a calcium sulfate screed with high residual moisture?

Calcium sulfate flow screeds must be abraded, vacuumed and primed with ASO-Unigrund-K, ASO-Unigrund-GE or ASO-Unigrund-S. The moisture content of a calcium sulfate based screed must be determined with a CM device (carbide hygrometer) before installing tiles. If ceramic tiles or slabs are to be laid on calcium sulfate based screeds with higher moisture levels than given in current regulations, levels of max 1.5% for unheated and 1.0% for heated constructions can be accepted. The flooring to be laid in this case must have a minimum joint content of 2% (tile 40/40, 4 mm joint), with vapour permeable tiles the joint content can be lower. Suitable tile adhesive: UNIFIX-AEK.
The installation of tiles on substrates not yet ready to receive finishes is to be evaluated as a special construction and agreed with the client.

Is it necessary to waterproof beneath tiles in wet duty areas?

Tiled finishes will, as far as the limitations of the grout are concerned, allow water to penetrate so that they require waterproofing in wet duty areas in order to protect the substrate from moisture. Dependent on the wet duty classification the appropriate system must be used.

There are adhesive residues on an existing cement-based screed, What do I need to do in order to lay tiles?

Water soluble paint or adhesive residues must be removed. Gloss or oil-based paints must be abraded as necessary. Eliminate or prevent rising damp from the substrate. Prime the cleaned surface with the rapid drying, quartz filled dispersion based primer ASO-Unigrund-S. Tiles can then be installed once the primer has dried with LIGHTFLEX, SOLOFLEX-FAST, MONOFLEX-FB.

Existing uneven areas in a calcium sulfate screed need to be levelled - what is the procedure?

Calcium sulfate screeds must be abraded, vacuumed and primed with ASO-Unigrund-K, ASO-Unigrund-GE or ASO-Unigrund-S. Edge, bay, structural joints and movement joints are to be carried through or inserted into the planned locations and stopped with a suitable medium e.g. edge insulation strip RD-SK50. A suitable levelling compound is ASO-NM15. ASO-NM15 can be installed at a thickness from 2 mm - 30 mm.

When can tiles be laid on a newly installed cement-based screed?

Firstly a moisture measurement must be carried out. The CM moisture content may not exceed 2.0 CM% for unbonded or floating screeds. Heated screeds must be commissioned beforehand. With bonded cement-based screeds moisture measurements are not necessary. To fix the tiles, thin bed adhesives such as e.g. AK7P, SOLOFLEX, LIGHTFLEX etc. can be used. By using the highly flexible adhesives UNIFIX-S3 or UNIFIX-2K tiles can be laid on green cement-based screeds as soon as they will take foot traffic. With green screeds the incomplete curing process and the consequentially lower resultant strength is to be allowed for. No heavy loads may be placed on the substrate. Laitance layers must be removed before installing tiles. Fixing tiles to green screeds is to be appraised as a special construction and agreed with the client.

What systems does SCHOMBURG offer for the installation of tiles externally on balconies and terraces? What must be taken into account?

The choice of a suitable system is very important for the secure installation of stone and ceramic on balconies and terraces. Temperature changes which occur lead to stresses within the construction layers due to the different expansion rates of the installed materials. These must be constantly compensated for, so that there are no failures within the construction layers. Furthermore the edge length of the bays are to be restricted to 2 - 5 m dependent on the severity of the temperature demands. The bays should be kept as square as possible and have an aspect ratio of up to 1:2. Falls of 2% must exist or be constucted.

SCHOMBURG offers a selection of two systems:
System 1 (AQUAFIN-TBS): Waterproof with AQUAFIN-RS300 or AQUAFIN-2K/M-PLUS and carry out the tile installation with the highly flexible, two component tile adhesive UNIFIX-S3 or UNIFIX-S3-fast.
System 2: Waterproof with SANIFIN and install tiles with MONOFLEX-XL or UNIFIX-S3.

What advantages does a tiled finish offer?

A particular plus point for all types of tiled finish is hygiene. They are easy to clean and offer no possibility of germs spreading. Bacteria, fungal spores and other pathogens cannot nest. The antistatic properties allow allergy sufferers to breathe again because dust and mites are easy to remove. Above all ceramic is environmentally friendly and of ecological value. They are neutral in odour and taste, do not give off vapours and don't unintentionally absorb materials from the environment. And because as a rule tiles have a long life, the environment scores again. Tiles are the ideal floor covering for energy saving underfloor heating because the warmth from the heating can easily reach the stone or ceramic floor.

What must I allow for when tiling a calcium sulfate screed?

Calcium sulfate flow screeds must be abraded, vacuumed and as with all substrates with calcium sufate binders, primed with e.g. ASO-Unigrund-K, ASO-Unigrund-GE or ASO-Unigrund-S. Heated screeds must be commissioned to recognised technical regulations before installing the floor finish. In order to determine a substrate's readiness to receive finishes, moisture measurements must be carried out with a carbide hygrometer (CM device) - [calcium sufate screeds without underfloor heating 0.5 CM%, calcium sulfate screeds with underfloor heating 0.3 CM%]. Suitable adhesives are e.g. MONOFLEX-FB, LIGHTFLEX, SOLOFLEX.

What is meant by substrate preparation?

In order to remove adhesion inhibiting and non-stable layers such as e.g. dust, dirt, weak skins, laitance, paints, smoothing mortars etc, mechanical methods are suitable such as e.g. sweeping, sand-blasting, shot-blasting, high pressure water jetting, planing, scabbling etc. Existing cracks in the substrate must be sealed with an epoxy resin before installing tiles. If movement within the cracked area of a floating screed cannot be eliminated, then this must be brought through to the surface of the tiling as a movement joint. If this is not possible due to the way the crack runs, the crack is to be sealed with a reaction resin and a joint, matching the tile grid, cut alongside within the screed.

Which requirements must an old tiled finish fulfill and what preparation must be met in order to be able to lay tiles on an old existing tiled floor?

The previous tiled floor must be sound and load-bearing, loose areas are to be removed and to be evened out with an MGIII cement mortar. The substrate must be cleaned and all adhesion inhibiting residues such as e.g. lime, grease, dirt etc. must be removed. Cracks in the substrate are to be resin sealed with a reacion resin (ASODUR-K900). Mechanically abrading the old tiled floor increases the bond of the primer or contact coat. ASO-Unigrund-S is a special rapid adhesion promoting primer for absorbent and non-absorbent substrates. Apply ASO-Unigrund-S neat to the prepared old tiled floor with a lambs wool roller in a criss-cross technique. Once the primer is dry, tiles can be laid with the tile adhesives LIGHTFLEX, SOLOFLEX or AK7P.

Which grout should I use to grout natural stone laid on floors?

Either the multi-function flexible grout CRISTALLFUGE-PLUS (for joints up to 10mm) or CRISTALLFUGE-FLEX (for joints up to 20mm).

How is it possible to determine whether a substrate is suitable for ceramic tiles?

The assessment and preparation of the substrate is an essential component of the technical performance. According to the VOB the contractor is committed to professionally assess the substrate. Inadequately prepared substrates are often the reason for damage in the installed tiled finish. With a technically correct substrate preparation, the optimum adhesive bond with the tiled finish is produced. The following steps belong to a complete substrate assessment:
1. Visual inspection
2. Evaluation of the flatness. The acceptable tolerances are described in DIN 18202 "Tolerances in building construction". The evaluation is carried out with a straightedge and a slip gauge.
3. Wipe assessment: By wiping with the hand flat to the surface, contamination (e.g. dust) can be determined.
4. Tap test: By tapping - e.g. with a blunt hammer - voids and hollow areas can be recognised due to a change in sound.
5. Wettability test: By applying water - e.g. with a brush - the absorption of the substrate can be assessed. The water must be taken up by the substrate within a short time period. If this is not the case, this can be indicative of high moisture, separating agent residues, cement laitance or similar.
6. Hammer blow test: This evaluation serves to determine thinner, harder layers found over soft zones. The hard crust on the surface of the substrate breaks up in pieces during the test.
7. Grid scratch test: By scratching the surface of the substrate in a diamond pattern using the 'Grid scratch' equipment, the surface condition (layers, hardness etc.) can be appraised. At the intersections where the surface has been scratched in a grid there may not be any simultaneous defects / delamination.
8. Moisture measurement: Moisture measurement is a test to determine the readiness of a substrate. The maximum moisture content, when measured with a carbide hygrometer (CM device), for the installation of tiles must amount to 2.0% for cement-based screeds (unbonded or floating) and 0.5% for calcium sulphate screeds (unheated) and 0.3% heated. Electronic moisture measuring devices may give a non-destructive measurement but the accuracy cannot however be taken for granted. If needs be they do offer guide values.

How can tiles be laid on chipboard and floorboards?

Wooden substrates must be clean and load-bearing. Chipboard must be interlocked, screw fixed and glued. Damaged timber / timber board substrates are to be replaced, loose boards professionally fixed (e.g. screws etc.). Close joints between boards with a suitable acrylic sealant. Ensure there is a minimum 5 mm gap around the boards where they meet interuptions / walls by inserting the self-adhesive edging strip RD-SK50.
An especially rapid and waterr-free solution for levelling substrates is offered by the epoxy resin screed ASODUR-LE. Suitable tile adhesives: UNIFIX-S3-FAST, LIGHTFLEX, MONOFLEX-FB.
Another alternative is offered with the thermally insulating impact sound deadening and de-coupling board STEPBOARD in 9 or 15 mm. Here the wooden substrate can be pre-smoothed with the wooden floor smoothing compound SOLOPLAN-FA. Once the levelling compound is dry, install the de-coupling board with an appropriate tile adhesive e.g. MONOFLEX-FB. Stagger the boards i.e. avoid cruciform joints. The tiles can be laid on the fixed STEPBOARD with MONOFLEX-FB or LIGHTFLEX.

What needs to be done to poured asphalt screeds in order to be able to lay tiles?

In order to lay tiles onto a poured asphalt screed, it must have a minimum quality of AS-IC 10 and a minimum thickness of 25 mm. There must be a 10-15 mm wide movement joint in the poured asphalt screed against interuptions in the floor, that must be carried through to the final floor finish. If the poured asphalt is newly installed, ensure that it is fully blinded with quartz sand. If this is not the case then before waterproofing and tile installation, prime the substrate with an epoxy resin such as ASODUR-GBM and broadcast with 0.1 - 0.6 mm quartz sand whilst the resin is still fresh. Suitable tile adhesives: UNIFIX-S3-FAST, LIGHTFLEX, MONOFLEX-FB.

5. Industrial Floor Coating

At what stage do cement bonded substrates achieve the required remaining moisture content of 4% when applying reactive epoxy resin coated surfaces ?

This depends on the layered thickness of the required construction and ambient environmental conditions. The required moisture content can be achieved after a period of 28 days, in general for cement screed surfaces and after approx. 3 months for applied monolithic concrete substrates.

Can the curing time of the 2 K-Epoxy or PU-resins be influenced by additional application of different curing quantities ?

No, due to the variation of the specified mix ratio the surplus components can not bind ie: the coating does not harden or would harden leaving an uneven state (soft parts).

Does a surface sealing on a freshly layed screed flooring require mechanical preparation (ie: shotblasting etc)?

The substrate must be prepared using suitable methods, so that an open-pored surface suitable to receive coatings is achieved. All adhesion inhibiting substances must be removed. This can be carried out by blast cleaning techniques, planing or similar methods.

When do I need to deaerate a resin floor coating with a spiked roller?

With coatings where the material consumption is from 1.5 kg/m² or greater per coat. The dearation process should not be carried out until approx. 20 minutes after product application.

Why does the 2-component epoxy resin react so quickly that the material cannot be processed continuously?

Temperature of the material and substrate as well as the stated pot life are substantial for the reaction of the material. After the material has been mixed (see details in the technical data sheet)it has to be spread onto the substrate immediately so that the material can immediately take over the temperature of the substrate which results in a prolonged material reaction time. The more compact the material is in its bucket the quicker is the material reaction time. A processing container with large diameter should be used. Never process the material directly out of the supplied buckets.

Which type of equipment and/or tools are required for application of epoxy resin coatings ?

Mixing the components: with a slow running mixer or hand drill (approx. 300 rpm) (Seperate to the Pail supplied), with mixing rod affixed, mixing paddle and Spirit level.

Application of the coat in rolled method: using a brush, or lint free, solvent resistant fur roll.

Application using the Spactling method (running coat): with trowel and/or scraper, serrated scraper, spiked roller, wearing spiked shoes for easier grip.