Knauf Dritherm 32 Ultimate 100mm High Performance Cavity Slab Insulation
1200 x 455mm (Pack 6) (3.28 sq m)
The demand for this product is already high especially in New Build Housing where walls insulated using this product will achieve a U-value of 0.19 W/m²K with any 100mm Concrete Block and 0.18 W/m²K with a wide range of 100mm lightweight aggregate blocks¹.
As with other products in the Earthwool DriTherm range, it will be supplied on Supakube pallets that that can be stored outside. A Supakube contains 30 packs of four slabs and each pack is fully enclosed to protect the product when being handled on site.
¹Brick outer leaf and 12.5 mm plasterboard on dabs lining
Advantages of Earthwool DriTherm 32 for Builders:
- The trusted brand
- Faster and more cost effective to install than rigid foam boards
- BBA certified and suitable for use in all exposure zones
- Moisture resistant
- Non-combustible Euroclass A1 Reaction to Fire rating
Advantages of Earthwool DriTherm 32 Ultimate for builders merchants:
- Up to 50% greater m² per pallet than competitor mineral wool products
- All packs are fully sealed for maximum product protection
- Supakube is fully Encapsulated so can be stored outside
More information of Earthwool DriTherm Cavity Slabs
A word about blocks and insulation
You tell us that there are currently shortages of certain types of blocks. These are generally ones with better thermal performance such as aircrete and very lightweight aggregate.
This means that the builder often has to switch to medium and dense concrete blocks and an improved insulation product may be required to ensure that the U-value is still met. Switching from DriTherm 37 Standard to the equal thickness of DriTherm 32 is a simple way to overcome this difficulty.
What is Earthwool DriTherm 32 Ultimate?
Earthwool DriTherm is the leading brand of mineral wool cavity slab for the thermal insulation of masonry cavity external walls in residential and non-residential buildings.
It is available in a range of thermal conductivities to meet the increasing demands of customers and building regulations.
Earthwool DriTherm 32 Ultimate has been developed as the highest performing product in this range with a thermal conductivity of 0.032 W/mK.
This allows building regulation compliant U-values to be achieved in normal cavity widths with all types of blocks, and for simplicity we have identified universal solutions to the different building regulation requirements that achieve compliance whatever block type is used.
We have just added a 150mm thick version of this product to the range to reflect the demand from our customers.
Earthwool DriTherm 32 has already been used on many new build projects including very high performing passive house projects such as Steel Farm and Denby Dale as well as more regular commercial developments.
Thermal Performance
Why is Earthwool DriTherm 32 Ultimate required?
Building Regulations have driven improvements in the energy efficiency of buildings, whether they be completely new buildings, or extensions to existing buildings.
A major contribution to this has been the improvement of the thermal insulation of external walls. Building regulation compliance for insulation is all about U-values so first it is necessary to understand a little about them
The U-value of a wall is calculated from its constituent components. The DriTherm component has the greatest influence on the U-value. However the other components can make small but critical differences.
The block type generally has the next biggest influence and if aircrete blocks were included they would improve the performance and dense concrete would worsen it.
Using wet plaster rather than plasterboard on dabs worsens performance and using a block and render outer leaf rather than brick improves performance.
More information of Earthwool DriTherm Cavity Slabs
Extensions
In extensions to existing buildings there are different requirements for each nation in the UK. Indeed to make matters more confusing in Scotland there are three depending on the type of building and in houses the performance of the existing building.
The table below shows the requirements for each country and the universal solution that achieves the U-value no matter what configuration of outer leaf, inner leaf and lining is chosen alongside it.
| Country | Maximum U-Value | Universal Solution for all configurations |
|---|---|---|
| England | 0.28 W/m²K | 100mm Earthwool DriTherm 32 Ultimate |
| Wales | 0.21 W/m²K | 150mm Earthwool DriTherm 32 Ultimate |
| Scotland (Domestic) | 0.19 W/m²K or 0.22 W/m²K | 150mm Earthwool DriTherm 32 Ultimate |
| Scotland (Non-domestic) | 0.25 W/m²K | 125mm Earthwool DriTherm 32 Ultimate |
| Northern Ireland | 0.28 W/m²K | 100mm Earthwool DriTherm 32 Ultimate |
Because there are so many variations in the type of block and the other factors that influence the U-value there are a large number of possible to solutions. If you require advice please refer to our detailed U-value tables or call our Technical Support team on 01744 766666 or email technical.uk@knaufinsulation.com.
New Build
The situation with New Build is more complex because there are different requirements for Domestic and Non Domestic Buildings in all countries. Additionally building regulations compliance is based around the building emission rate calculated in SAP or SBEM.
The wall U-value is not fixed so long as it does not exceed a maximum value, commonly called a backstop. So if we focus on Dwellings, in England and Scotland the building is unlikely to comply with a wall built merely to the backstop requirement where as in Wales it would.
At Knauf Insulation we have considerable experience of completing SAP analysis for customers and understand that the suggested U values will normally result in an overall compliance.
The table below shows the requirements for new build dwellings for each country and the universal solution that achieves the U-value no matter what configuration of outer leaf, inner leaf and lining is chosen alongside it.
| Country | Backstop U-Value | KI Suggested U-Value | Universal Solution for all configurations |
|---|---|---|---|
| England | 0.30 W/m²K | 0.21 to 0.25 W/m²K | 100 to 150mm Earthwool DriTherm 32 Ultimate |
| Wales | 0.21 W/m²K | 0.21 W/m²K | 125 to 150mm Earthwool DriTherm 32 Ultimate |
| Scotland | 0.25 W/m²K | 0.19 W/m²K | 150mm Earthwool DriTherm 32 Ultimate |
| Northern Ireland | 0.30 W/m²K | 0.21 to 0.25 W/m²K | 100 to 150mm Earthwool DriTherm 32 Ultimate |
Because there are so many variations in the type of block and the other factors that influence the U-value there are a large number of possible to solutions. If you require advice please refer to our detailed U-value tables or call our Technical Support team on 01744 766666 or email technical.uk@knaufinsulation.com.
More information of Earthwool DriTherm
***THIS ITEM IS FOR COLLECTION OR NEXT DAY DELIVERY WITHIN 8 MILES OF PL5 3LR ONLY***
IF DELIVERY IS REQUIRED OUTSIDE THIS AREA PLEASE CONTACT US ON 01752 751136
