Building regulations for roof insulation
Roof insulation thickness for building regulations will vary depending on the type of insulation used. Used within a Bauder waterproofing system our products meet current UK Building Regulations Part B for fire protection.
Different insulants have different efficiencies and performance levels which affects the thickness required to meet building regulations. This table shows a comparison of the insulations when looking to achieve different U-values on a plywood deck.
Warm roof insulations
| 0.11W/m²K on a plywood deck | 0.13W/m²K on a plywood deck | 0.18W/m²K on a plywood deck | ||||
|---|---|---|---|---|---|---|
| Insulation Type | Thickness (mm) | Approx Weight Loading (kg/m²) | Thickness (mm) | Approx Weight Loading (kg/m²) | Thickness (mm) | Approx Weight Loading (kg/m²) |
| BauderPIR FA-TE | 200 | 6 | 160 | 4.8 | 120 | 3.6 |
| BauderPIR FA | 200 | 6 | 160 | 4.8 | 120 | 3.6 |
| BauderPIR FA G16 (average thickness) | 200 | 6 | 160 | 4.8 | 120 | 3.6 |
| BauderVIP TE* | 110 | 17.9 | 80 | 17 | 60 | 13 |
| BauderROCK | 335 | 53.6 | 290 | 46.4 | 200 | 32 |
| BauderGLAS | 310 | 31 | 260 | 26 | 190 | 19 |
*U-value based upon ratio of 80% BauderVIP TE in combination with 20% BauderPIR FA-TE with an additional 30mm layer of BauderPIR FA-TE for 0.11W/m²K.
Inverted roof insulations
Key:
*1 layer
** 2 layers
*** 3 layers
BauderGLAS Inverted includes a base layer of BauderGLAS T3+
Excluding correction in BS6229:2018 - 4.6.2.2 Inverted Roofs
| 0.11W/m2K on a 150 mm concrete deck with a lambda value of 2.500 W/mK | 0.13 W/m2K on a concrete deck with a lambda value of 2.500 W/mK | 0.18 W/m2K on a concrete deck with a lambda value of 2.500 W/mK | ||||
|---|---|---|---|---|---|---|
| Insulation Type | Thickness (mm) | Approx Weight Loading (kg/m²) | Thickness (mm) | Approx Weight Loading (kg/m²) | Thickness (mm) | Approx Weight Loading (kg/m²) |
| BauderJFRI PREMIUM+ Hard Landscape | 265** | 7.95 | 225** | 6.75 | 165* | 4.95 |
| BauderJFRI PREMIUM+ Soft Landscape | 280** | 8.40 | 240* | 7.20 | 175* | 5.25 |
| BauderJFRI PREMIUM 300 Hard Landscape | 280** | 11.20 | 240* | 9.60 | 175* | 7.00 |
| BauderJFRI PREMIUM 300 Soft Landscape | 300** | 12.00 | 255** | 10.20 | 185* | 7.40 |
| BauderXPS 300 | 310*** | 9.30 | 260*** | 7.80 | 190** | 5.70 |
| BauderGLAS Inverted | 360** | 36.00 | 300** | 30.00 | 220** | 22.00 |
Including correction in BS6229:2018 - 4.6.2.2 Inverted Roofs
| 0.11W/m2K on a concrete deck with a lambda value of 2.500 W/mK | 0.13 W/m2K on a concrete deck with a lambda value of 2.500 W/mK | 0.18 W/m2K on a concrete deck with a lambda value of 2.500 W/mK | ||||
|---|---|---|---|---|---|---|
| Insulation Type | Thickness (mm) | Approx Weight Loading (kg/m²) | Thickness (mm) | Approx Weight Loading (kg/m²) | Thickness (mm) | Approx Weight Loading (kg/m²) |
| BauderJFRI PREMIUM+ Hard Landscape | 290** | 8.70 | 250** | 7.50 | 180* | 5.40 |
| BauderJFRI PREMIUM+ Soft Landscape | 310** | 9.30 | 265** | 7.95 | 190* | 5.70 |
| BauderJFRI PREMIUM 300 Hard Landscape | 310** | 12.40 | 265** | 10.60 | 190* | 7.60 |
| BauderJFRI PREMIUM 300 Soft Landscape | 330** | 13.20 | 280** | 11.20 | 200* | 8.00 |
| BauderXPS 300 | 340*** | 10.20 | 290*** | 8.70 | 210** | 6.30 |
| BauderGLAS Inverted | n/a | n/a | 320** | 32.00 | 230** | 23.00 |
England and Wales - Part L of Building Regulations - Conservation of fuel and power
Separate criteria are set out in approved documents; L1 is specific to dwellings and L2 relates to buildings other than dwellings. These are then split into four sections and for new construction are based on notional buildings:
- L1A New Dwellings - 0.13 W/m²K
- L1B Existing Dwellings - 0.18 W/m²K
- L2A New Buildings other than Dwellings - 0.18 W/m²K
- L2B Existing Buildings other than Dwellings - 0.18 W/m²K
More via Government Planning Portal ►
Scotland - Section 6 of the Scottish Building Regulations - Energy
Revised target levels for roofs are to be implemented from October 2015 and are approaching or exceeding the Passivhaus standard for buildings:
- Domestic buildings - 0.11 W/m²K
- Non Domestic buildings - 0.18 W/m²K for heated and naturally vented notional buildings
- Non Domestic buildings - 0.16 W/m²K for heated and mechanically vented notional buildings
More via The Scottish Government ►