Thermano Compact: how to insulate small details where heat escapes

Changing lambda alone is not enough, because convenient handling of a smaller board does not determine whether the whole installation is correct. The solution should allow work to be organised on a small section without abandoning the layer and joint design. As a starting point for comparing variants, record the dimensions of the installation location, the access width and the planned position of every joint.

For Thermano Compact, the manufacturer declares a lambda of 0.023 W/(m·K). The thickness must be selected both for the expected thermal resistance and for the space available.

When comparing polyurethane boards, take into account the narrow strip of insulation whose thickness is limited by the existing building detail. The resistance of a small insert should be assessed together with the geometry of the materials surrounding that piece, so that the comparison concerns the same thermal effect. The result must be read cautiously, since the influence of a narrow strip on the thermal bridge also depends on the geometry of the materials around it. The calculation is intended to help assess the benefit of insulating the detail without transferring the R result to the whole junction. In the energy summary, show the width and thickness of the insert and the continuity of insulation in the adjoining sections, so that it is clear what exactly changed between the solutions.

A small cut of Thermano Compact may solve an important detail, even though its area will be small. However, this benefit cannot be assessed solely by its share of the total insulation area. It is necessary to see what the piece is in contact with and where the path of heat conduction still runs. With complex geometry, an analysis of the junction is helpful. A well-fitted small board should support the continuity of the layer, not create the appearance of improvement at a randomly chosen location.

Thermano Compact comes in the BASIC and TOP variants. After cutting, the groove may disappear from one edge, so the way the new joint is made has to be planned.

Check a cut piece taken from a TOP board, which after shortening loses part of the factory overlap, because continuous polyurethane insulation also requires correct terminations. After cutting a TOP board, the joint between the retained rebate and the new straight edge must be planned, because losses at joints must be assessed together with the main insulation field. A good connection does not arise automatically, since using offcuts requires support and proper closing of the new joint. The layout of elements should allow the cutting method to be matched to the actual direction in which successive pieces are laid. On the detail drawing, show the position of the rebate on every element used and the stability of the resulting strip at the perimeter; this record will make later inspection of the work easier.

The Thermano Compact facing does not remove the need for moisture protection. At the detail, the treatments and the joints with the window, wall or substrate also matter.

When assessing the durability of the thermal effect, include the connection of the small PIR insert to the substrate and flashing in a location exposed to water. The protection of a small piece of insulation must also cover its connections to the surrounding material, if the insulation is to perform under the conditions assumed in the design. Polyurethane foam does not replace protective layers: the facing surface may be undamaged while water can still enter through an unclosed side. The planned protection should cover the detail together with its terminations instead of protecting only the middle of the board. Before covering, assess the drainage path, the condition of the flashing and the connection of materials on all sides of the insert, because later repair may require opening the finished assembly.

For Thermano Compact, at least 150 kPa at 10% deformation is declared for thicknesses up to 30 mm, and 200 kPa from 40 mm. The product’s reaction to fire class is E.

The thickness limitation does not exempt the other requirements from being checked, so analyse the difference between the declared CS150 up to 30 mm and CS200 from 40 mm. The CS value for Thermano Compact must be assigned to the thickness shown on the board marking, even when the choice of board was mainly determined by its low lambda. A separate assessment is needed because the appearance of two boards does not show which declaration range each belongs to. Only the complete set of data will allow the pressure on the detail to be assessed while retaining the data of the precisely selected variant. Alongside the thermal results, state the thickness on the label, the bearing area and the way the anticipated load is distributed; this will ensure the comparison does not omit the service conditions.

The requirement for Thermano Compact is best calculated on the basis of the cutting layout, not just the area of the recesses. A narrow offcut may not be usable in the next location.

Polyurethane board insulation should have its effect and scope of work calculated; include a set of several small pieces whose combined area does not show the number of full boards. All the required cuts should be laid out on the 600 × 1200 mm format before purchasing packs, so that the cost relates to one comparable result. The price of the material is only part of the decision, since narrow remnants may not fit the next location despite matching material thickness. The final summary should allow waste to be reduced by matching the cutting layout to the actual shapes of the required elements. Ask for a cutting sketch, the number of full boards and the possibility of safely using the remaining pieces, so that any surcharge has a stated technical justification.