Thermal bridges are weak points in the building envelope through which increased heat losses occur. They most often appear at the joints of SIP panels, at bearing points, and along structural elements. Even with the high thermal insulation performance of the polystyrene core inside a SIP panel, without proper measures the thermal envelope is “broken” at these areas.
One of the most effective solutions is the use of thermal inserts — insulating elements that replace or supplement wooden connection splines in SIP panel construction.
To calculate houses with thermal inserts in SIP CALC, registration is required. Learn more about registration…
Why use thermal inserts?
- Reduced heat loss
Thermal inserts significantly reduce thermal conductivity at junctions by interrupting the direct thermal bridge from the external OSB layer to the internal one. This keeps the energy efficiency of the construction at a level very close to that of the SIP panel itself. - Improved indoor comfort
Using thermal inserts prevents cooling of the inner surface of walls or floors, eliminating the risk of condensation, dampness, or mould in these areas. - Features of use in floor structures
Without thermal inserts, the U-Value of the structure can increase by 1.5–2 times at joints. Inserts minimise these deviations and ensure uniform insulation across the entire surface.
Features of use in floor structures
When designing inter-storey floors with SIP panels, it is important to consider not only insulation but also the load-bearing capacity of the structure
- SIP floors with thermal inserts are laid on supporting beams or trusses; such support elements remain mandatory.
- In ground floors connected to the foundation, joists must be added to ensure both load distribution across SIP panels and sufficient structural rigidity.
- This approach increases timber consumption for additional support elements but also enhances the overall energy efficiency of the SIP house.
Thermal inserts — effective protection against thermal bridges
Thermal inserts are the key to a truly energy-efficient SIP house. They:
- reduce heat loss through wall and floor joints,
- save costs on maintaining a comfortable indoor climate,
- create a continuous, closed insulation envelope.
It is especially important, for maintaining strength and rigidity in floors with thermal inserts, to correctly calculate supporting structures made of timber beams or trusses and their spacing. Only in this way can one achieve the optimal balance of reliability and energy efficiency in a modern house.
Attention! The SIP CALC calculator does not calculate the materials required for additional support structures when using thermal inserts!
To try out the thermal insert function in SIP CALC, register and then activate this feature in your personal account.