What changes when you choose 150 or 200 mm mineral wool panels in a wall design?

These are the values for a specific configuration. A different family, core or lock may give different results. Combining the lowest U from one table with the lowest mass from another creates a product that does not exist. In any comparison, keep the full description of both variants.

At the same area and temperature difference, a lower U means a smaller heat flux. The difference between 0.27 and 0.20 is around 26% of the initial value. This applies to transmission through the compared panel field, not to all losses and heating bills.

In a building with large, frequently opened gates, air exchange will also matter. In the office zone, the share of openings and details may be of different significance. Before thickening the entire façade, it is worth calculating whether this step or refining the plinth and the airtightness of the joinery brings the greater improvement.

A thicker core may occur in a solution with higher fire resistance, but this requires confirmation for the specific assembly. The EI class also depends on the joint, fixing, orientation and span. It should not be assumed that every 200 mm will have a higher class than every 150 mm.

If fire requirements determine the choice, check the scope of classification before refining the façade. Gates, doors and service penetrations must correspond to the function of the separating element. Changing the panel alone does not automatically raise the parameters of the other wall elements.

The additional 50 mm affects either the projection of the external plane or the width of the internal space, depending on the mounting axis adopted. It must be established where the windows, gate tracks and plinth flashings will remain. Without this, the detail can only be adjusted on site.

Extended window sills and flashings should not create unsupported sections or retain water. The core must be properly closed at the corners. The length of the fastener components also changes, so the accessory list from the thinner version cannot be transferred automatically.

For a façade of 300 m² of panels, a difference of 5 kg/m² means 1,500 kg of additional material mass. This is an example based on the variants described earlier. The designer must verify how this is transferred to the supports, and the contractor must include the mass of individual elements in the lifting plan.

Greater thickness may change the permissible spans, but it does not mean that rails can be removed freely. Load-bearing capacity, deflections, connections and fire requirements must be verified. It is worth comparing variants of the entire wall rather than assuming that a larger core will automatically solve every structural problem.

A new building may consist of a heated section with a thicker wall and a lower unheated wing. At their junction, the façade line and the run of the flashings must be established. Drainage from the lower roof should not discharge onto an unprotected panel edge, and the difference in thickness must not be masked by an arbitrary void.

It is worth showing this location in section together with the structure and insulation. This makes it possible to identify the local thermal bridge and the location requiring continuous sealing. The choice of 150 or 200 mm then has a clear relationship to the function of each part of the building. The transition between variants becomes a designed detail instead of a later task for the person carrying out the flashings.

In the documentation, indicate whether the entire envelope is to have the same thickness or whether different zones will receive different panels. The transition between them requires a deliberate detail. A change in thickness at an arbitrary location can disturb the façade plane and make it difficult to achieve continuous sealing.

Complete the selection by checking the cost of panels, accessories, equipment and works. It is also worth assessing the expected use of the building. If the zone will be continuously heated, the thermal argument has a different significance than for an unheated warehouse. The best thickness results from this balance and the project requirements.