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Building physics and cost-effectiveness

How the coating works — and what it saves

Two diagrams answer the question. The first shows what happens at the wall, the second why it happens. You can then use the same figures to work out what it's worth for your building.

The claim isn't "warmer" — it's "above the mould-risk threshold".

What matters for an existing building isn't comfort, but the temperature of the room-side surface. If it falls below the mould-risk threshold under DIN 4108-2, mould grows — regardless of how well the room is heated. The cross-section shows both cases on the same wall.

Cross-section of a 24 cm solid brick wall showing the temperature profile without and with interior coating Horizontal cross-section through the wall, left to right: outside air, 15 mm exterior render, 24 cm solid brick masonry, 15 mm interior render, 1 mm coating (shown greatly exaggerated in scale), inside air. The render and masonry layers are drawn to scale relative to each other; only the coating is exaggerated. The vertical axis shows temperature from −5 °C to 21 °C. The dashed curve applies without coating, the solid curve with coating; both curves are also labelled directly and so are not distinguished by colour alone. Without coating, the temperature drops from 21 °C room air to 13.0 °C at the interior surface, which is below the mould criterion of 13.2 °C and only 0.1 K above the dew point of 12.9 °C. With coating, the interior surface temperature is 19.7 °C, 6.5 K above the mould criterion. Both surface temperatures were measured at the property, not in a test rig under standard conditions. The profile within the component is back-calculated from these using R_si = 0.13, R_se = 0.04 and 0.015 m²K/W per render layer, and is not measured at any point; the entire measured difference is thereby mathematically attributed to the coating layer. This means the render surface behind the coating is calculated at −2.1 °C rather than 13.0 °C - condensation within the component cross-section must therefore be assessed separately per DIN 4108-3 and is not addressed by this drawing. −505101520 °C Mould criterion 13.2 °C · calculated value per standard DIN 4108-2, f_Rsi = 0.7, at −5 °C / 21 °C Dew point 12.9 °C · calculated value per standard at 21 °C room air and 60% RH Risk zone below 13.2 °C Surface below the mould criterion with coating · 19.7 °C solid line Field measurement, evidence pending without coating · 13.0 °C dashed line Field measurement, evidence pending Coating 1 mm - shown exaggerated Outside air External render 15 mm Masonry 24 cm Internal plaster 15 mm Inside air outside −5 °C · inside 21 °C · 60% RH · wall build-up: 24 cm solid brick + 15 mm lime-cement render
G1 - Component cross-section with temperature profile. The point is not "warmer", but "out of the mould criterion": without coating, the internal surface at 13.0 °C lies below the mould criterion of 13.2 °C; with coating, at 19.7 °C it lies clearly above it.
Surface temperatures 13.0 °C and 19.7 °C: Field measurement on a multi-family building of reinforced-concrete frame construction. Boundary condition: outside -5 °C / inside 21 °C / 60% RH. Measured at the property, not in a test rig under standard conditions.
Dew point 12.9 °C and mould criterion 13.2 °C: Calculated value per standard - dew point per the Magnus formula for 21 °C and 60% RH, mould criterion per DIN 4108-2 with f_Rsi = 0.70 at -5 °C outside and 21 °C inside.
All other temperatures within the component (−2.5 / −1.6 / 12.1 °C without, −4.6 / −4.5 / −2.2 / −2.1 °C with coating): calculated values, back-calculated from the two measured surface temperatures using R_si = 0.13, R_se = 0.04 and 0.015 m²K/W per plaster layer. No measurements were taken at these points.
The measured difference is attributed entirely to the coating layer - a model assumption, not a material property. This results, by calculation, in a colder plaster surface behind the coating (−2.1 instead of 13.0 °C); interstitial condensation must be assessed separately in accordance with DIN 4108-3 and is not addressed by this drawing.
Scale: the plaster and masonry layers are drawn to scale relative to one another (1.5 units per mm). Only the 1 mm coating thickness is shown exaggerated, so the layer remains visible.
Values as a table
Temperatures in the component cross-section, boundary condition: outside −5 °C · inside 21 °C · 60% RH · wall build-up: 24 cm solid brick + 15 mm lime-cement render
PositionTemperature without coatingTemperature with coatingReference valueBasis
Outside air−5,0 °C−5,0 °Cno limit value (assumed boundary condition)Assumed boundary condition, not a measurement.
Outer surface (exterior render)−2,5 °C−4,6 °Cno limit valueCalculated value – back-calculated from the two measured surface temperatures via the layer resistances. Not measured at this point.
Transition exterior render / masonry−1,6 °C−4,5 °Cno limit valueCalculated value – back-calculated from the two measured surface temperatures via the layer resistances. Not measured at this point.
Transition masonry / interior render12,1 °C−2,2 °Cno limit valueCalculated value – back-calculated from the two measured surface temperatures via the layer resistances. Not measured at this point.
Room-side render surface (beneath the coating)13.0 °C (= interior surface, no coating present)−2,1 °Cno limit value; condensation within the cross-section must be assessed separately per DIN 4108-3Calculated value – a consequence of the model assumption that the entire measured difference is attributed to the coating layer. Not measured at this point.
Interior surface (room side)13,0 °C19,7 °CDew point 12.9 °C / mould criterion 13.2 °CField measurement of the surface temperature at the property. Limit values: calculated per standard.
Inside air21,0 °C21,0 °Cno limit value (assumed boundary condition)Assumed boundary condition, not a measurement.

The working principle: radiation, not thickness

A 1 mm layer cannot build up any meaningful insulating effect through its thickness alone. The effect works via emissivity: a surface that radiates less heat stays warmer. This is the same low-E effect used in a coated insulating glass pane.

Radiation balance: emissivity of standard render and PowerSmartCoat comparedTwo side-by-side half-images, each with a vertical wall edge and a fan of arrows representing heat radiation into the room. On the left, standard render with an emissivity of around 0.90 (literature value): ten thick arrows, radiated output 100 percent as the reference value. On the right, PowerSmartCoat with an emissivity of 0.25: only three thin arrows, radiated output around 28 percent. The number of arrows encodes the magnitude of the radiation. The comparison is made at the same surface temperature; the overall effect on the component also depends on convection and thermal conduction.Standard renderEmissivity around 0.90Literature value for mineral render10 Pfeileradiated power, relativecalculated, based on literature value100 %PowerSmartCoatEmissivity 0.25System data PSC 250 T3 Pfeileradiated power, relativecalculated from the emissivitiesaround 28%Comparison of emissivities at the same surface temperature. The overall effect on the componentalso depends on convection and thermal conduction.
Figure G2: Radiation balance and emissivity. Method: comparison of radiated power according to Stefan-Boltzmann, where power is proportional to emissivity. Boundary condition: identical surface temperature, identical area, identical surroundings; the relative radiation is 0.25 divided by 0.90, equal to around 28 per cent. The value 0.90 for mineral render is a literature value; the value 0.25 comes from our own system data. What is shown is a low-E effect, i.e. reduced thermal radiation from the surface. It is not a lambda value and does not replace an insulation layer.
Values as a table
Radiated power at identical surface temperature, relative to standard render equal to 100 per cent.
SurfaceEmissivityrelative radiationBasis
Standard render, mineral-basedaround 0.90100 %Literature value for mineral render
PowerSmartCoat0,25around 28%System data PSC 250 T

Calculation: relative radiation equals emissivity divided by 0.90. The graphic encodes magnitude via the number of arrows, ten versus three, so the difference remains countable even for colour-blind viewers and in black-and-white printouts. Comparison of emissivities at the same surface temperature. The overall effect on the component also depends on convection and thermal conduction.

Cost-effectiveness

Work it out for yourself

The diagrams above show the effect on a standard building component. Work out here what it means for your own building: using the degree-day method, entirely in your browser — no network, no storage. The result is an order of magnitude for the customer conversation, not an invoice.

Assumptions

Net area of the coated components, excluding windows and doors.

From the energy performance certificate or the known wall construction. Unknown? Estimate from three temperatures.

Your assumption, not a product guarantee. There is no verified U-value certification for the coating. When advising customers, calculate deliberately conservatively.

Unit price from the customer's latest bill.

Annual utilisation rate of the heat generation, between 0.5 and 1.0.

Material and labour combined. You'll find the material price under the packages; your company calculates the labour share.

Depends on location; typically 3,000 to 4,200 Kelvin-days in Germany.

Result

Savings

Heating demand before

Heating demand after

U-value after
Heating costs before
Heating costs after
Total investment
CO₂ saved
Payback period

Change an assumption and the result recalculates instantly.

Method: Degree-day method, Q = U · A · Gt · 24 / 1000. Thermal bridges, ventilation and solar gains are not included in this. CO₂ calculated using 0,201 kg per kWh of natural gas. The result is an order of magnitude for the consultation and not an invoice. It is calculated entirely in your browser: no transmission, no storage.

For the applying contractor

Technical data sheet

Application, consumption, limits of use, aftercare and labelling — in the order in which they are needed on site.

Basis All information is taken from our PSC 250 T system manual. Where a declared parameter underlies a value, it is stated below the line. For classification, first aid and disposal, the current safety data sheet also applies.

System
PSC 250 T — primer ECB BASIC B, functional layer BUILD, finish ECO OUTSIDE
Status
System manual version 1.0, June 2026 edition
Container labelling
The batch number and best-before date are stated on the label of the delivered container.

Block 01 — Application

Sequence, tools and times. All time specifications apply to the climatic conditions given below in block 03; colder or damper conditions extend every drying time.

Substrate
Load-bearing mineral and porous substrates: concrete, cement, masonry, stone, render, unglazed ceramic, plasterboard, fibre cement, concrete brick, timber and roofing felt — including old existing buildings and even listed façades, as long as they are consistently load-bearing.Boundary condition: dry, firm and load-bearing, free of loose material, oil, grease, dust, mould, salt and loose old coatings. Procedure: visual and wipe test for chalking, scratch and tap test for hollow areas, and if in doubt a pull-off or cross-cut test on the primer.
Pre-treatment
Remove loose and non-load-bearing old coatings, clean the surface and fill any defects. Measure substrate moisture: below 4%, below 2.5% for concrete.Procedure: moisture measurement with a suitable meter; if in doubt, wait until the substrate is ready to receive flooring/coating. Boundary condition: repairs must be fully dry before application.
Primer
PSC 250 T ECB BASIC B, ready to use, approx. 0.1 mm. Curing around 24 hours, recoatable after 2 to 3 hours without sanding.Boundary condition: no thinning is intended; mix the entire container contents thoroughly before use. The primer is essential for the adhesion of all subsequent layers and can be applied directly to corroded but stable surfaces.Basis: System data PSC 250 T
Application method
Airless spraying is preferred. Alternatively, brush or roller with 8 to 14 mm pile length.Boundary condition: only these application methods are approved. Other methods alter the layer thickness and therefore the function of the coating.
Airless — nozzle size
To be selected according to the spray equipment manufacturer's specification and the product. The equipment filter must be removed before application.Constraint: the filter must be removed because the coating contains ceramic nanospheres — it would hold them back and alter the spray pattern.
Airless — spray pressure
120 bar maximum.Constraint: maintain an even distance and overlapping passes so the film thickness stays uniform. Higher pressure increases overspray and reduces film thickness.
Number of coats
Three layers in a fixed sequence: primer, functional coat, top coat. The functional coat is applied in two passes.Constraint: the number of coats follows from the required dry film thickness, not from appearance. Opacity is not a measure of function.
Wet film thickness per coat
Functional coat 0.5 mm per pass. Primer approx. 0.1 mm, top coat 0.1 to 0.2 mm.Constraint: the two passes of the functional coat together give 1.0 mm. If either pass is applied thinner, the finished build-up will be short of thickness.Basis: System data PSC 250 T
Total dry film thickness
Approx. 1.2 mm across all three layers: primer approx. 0.1 mm, functional coat 1.0 mm, top coat 0.1 to 0.2 mm.Constraint: this applies to the complete system build-up. A partial application is not a thinner build-up, but a different one.Basis: System data PSC 250 T
Intermediate drying
The next coat can be applied as soon as the surface is touch-dry — after approximately 2 hours. For the functional coat, 4 to 8 hours.Constraint: recoatable without sanding. These figures apply to the climatic conditions given in block 03; colder or damper conditions extend every time given.Basis: System data PSC 250 T
Through-drying / load-bearing capacity
Curing approx. 24 hours per layer, drying at least 24 hours. Maturing time of the finished build-up 24 hours.Constraint: the fresh coating must be protected from rain and frost for at least 6 hours.Basis: System data PSC 250 T
Layer build-up in cross-section, schematicCross-section through the wall build-up. From inside to outside: substrate, primer ECB BASIC B, functional coat BUILD in two passes, and top coat ECO OUTSIDE. The bracket on the left runs from the substrate surface to the outer surface, indicating the dry film thickness of the entire build-up including the primer. The diagram is not to scale and contains no measured values.Total dry film thicknessapprox. 1.2 mmTop coat ECO OUTSIDEFunctional coat, pass 2Functional coat, pass 1Primer ECB BASIC BSubstrate / component
Layer structure in cross-section. The drawing shows the sequence of the layers, not their size ratio — the actual thicknesses are given in the table below. A to-scale drawing of the comparison is on the product page.
Values as a table
Layer sequence and layer thicknesses of the PSC 250 T system build-up
ItemLayerWet film thicknessDry film thicknessBasis
1Substrate / componentNot applicableNot applicableno measured value
2Primer ECB BASIC Bapprox. 0.1 mmapprox. 0.1 mmSystem data PSC 250 T
3Functional layer BUILD, 1st application0,5 mmcombined 1.0 mmSystem data PSC 250 T
4Functional layer BUILD, 2nd application0,5 mmcombined 1.0 mmSystem data PSC 250 T
5Top coat ECO OUTSIDE0.1 to 0.2 mm0.1 to 0.2 mmSystem data PSC 250 T
Total coating1.2 to 1.3 mmapprox. 1.2 mmSystem data PSC 250 T

Block 02 — Consumption and coverage

The basis for every calculation. Consumption figures are guide values on a smooth substrate; texture, absorbency and application method alter them considerably.

Consumption per coat
Primer 100 to 200 ml/m². Functional coat 0.9 l/m² over both passes. Top coat 0.18 to 0.30 l/m² depending on film thickness.Constraint: guide values on a smooth substrate. Texture, absorbency and application method alter them considerably; consumption becomes binding only once determined on a sample area.Basis: System data PSC 250 T
Total consumption
Approx. 1.2 to 1.4 l/m² for the complete build-up of primer, functional coat and top coat.Method: sum of the individual consumption figures from the row above. Constraint: excludes an allowance for cutting waste, overspray and detailing.Basis: System data PSC 250 T
Coverage
An 18-litre container of functional coat covers approx. 20 m². Primer approx. 90 to 180 m², top coat approx. 60 to 100 m² per container.Method: container content divided by consumption per square metre. Constraint: site-specific consumption must be determined on a trial area.Basis: System data PSC 250 T
Container sizes
18 litres. Primer 16.2 kg, functional coat 9.36 kg, top coat 16.2 kg per container.Constraint: note the batch number for each container; if multiple batches are used on one area, box-mix them beforehand.Basis: System data PSC 250 T

Block 03 — Application limits

These limits determine adhesion and film formation. If any is not met, the result cannot be remedied by rework — it must be rebuilt from scratch.

Application temperature, air
+5 °C to +30 °C.Constraint: below +5 °C no continuous film forms; above +30 °C the surface dries faster than the depth.Basis: System data PSC 250 T
Substrate temperature
+5 °C to +30 °C. The primer tolerates surface temperatures of up to +45 °C.Constraint: do not apply to a substrate in direct sunlight above +30 °C, even if the air temperature is within range.Basis: System data PSC 250 T
Relative humidity
Below 80%.Constraint: above this, film formation is delayed to the point that the intermediate drying times no longer apply.Basis: System data PSC 250 T
Dew point margin
Not separately declared. What matters is substrate moisture below 4% (concrete below 2.5%) and relative humidity below 80%.Constraint: the manual does not list the dew point margin as a separate limit value. Working to the usual 3-kelvin rule keeps within the limits stated above.
Unsuitable substrates
PE, HDPE, PP, PTFE and other plastics. Non-load-bearing or loose existing coatings. Surfaces in direct sunlight above +30 °C.Constraint: do not apply if rain or frost is expected; protect the fresh coating from either for at least 6 hours.Basis: System data PSC 250 T
Trial area / advance sample
Test on a site-specific trial area before full application.Method: sample area on the original substrate, same application method, same number of coats. Constraint: adhesion, appearance and actual consumption are determined on site, not taken from the data sheet.Basis: Procedural note

Block 04 — Aftercare, storage, disposal

What applies after the final pass: recoating, tools, leftover material and containers.

Overcoatability
Within the system, without sanding: primer after 2 to 3 hours, functional coat after 4 to 8 hours, top coat after 2 to 3 hours. The top coat can be tinted to RAL shades in the COLOR and SPECIAL COLOR versions.Constraint: third-party coatings over the finished build-up are not approved — they alter emissivity and vapour permeability, and thus function.Basis: System data PSC 250 T
Cleaning tools
With water, immediately after use.Constraint: the products are water-dilutable; dried-on material is difficult to remove.
Storage and shelf life
24 months in the unopened original container. Store and transport frost-free at +5 °C to +30 °C, protected from direct sunlight.Constraint: opened containers should be used promptly; the date on the container applies to unopened goods.Basis: System data PSC 250 T
Disposal
Send emptied containers for recycling. Liquid residues must not go into the drainage system — take them dried out, or as hazardous waste, to the local recycling centre.Method: the product-specific waste code under the Waste Catalogue Ordinance is given in Section 13 of the safety data sheet. It applies to the specific product, not generically to all coating materials.

Block 05 — Safety and labelling

This section does not replace a safety data sheet. For classification, first-aid and disposal information, only the current safety data sheet applies.

Safety data sheet
We supply the safety data sheet in accordance with Regulation (EC) No. 1907/2006 (REACH), Annex II, in its current version. It is available on request in advance.Constraint: the SDS must be available on site before first use and must feed into the risk assessment.
Hazardous substance labelling
Classification and labelling follow the CLP Regulation (EC) No. 1272/2008. Pictograms, the signal word, and H- and P-statements appear on the label of the delivered container and in Section 2 of the safety data sheet.Constraint: the label of the container actually delivered is always the authoritative source.
Personal protective equipment
Safety glasses, gloves and protective clothing. When spraying and in confined spaces, respiratory protection is additionally required, along with adequate ventilation and extraction of the spray mist.Constraint: spray application and work in enclosed spaces are subject to different requirements than rolling. Glove material and breakthrough time must be taken from Section 8 of the SDS.
VOC content
9.1 g/l for the functional coat, measured to PN-EN ISO 11890-1. The system value is 10 g/l maximum.Method: labelling under the German ChemVOCFarbV (implementing Directive 2004/42/EC), stating category, limit value and actual content.Basis: System data PSC 250 T