U-Value Tables

The U-Values achieved for typical cavity wall constructions using Airtec block inner leaves have been calculated and tabulated in the downloadable tables below. To demonstrate the thermal advantage of Airtec blocks over any other masonry block currently available, the u-values using all other types of block are also shown (the most thermally efficient block at the top row of the table, the least thermally efficient block at the bottom row).
 
Common insulation materials and thicknesses are shown across the top of the table and are in some cases are grouped together where the thermal properties are the same as another insulation material.
 
In all cases as regards the data on these tables, the following applies: -
  • Brick outer leaf.
  • Standard 12.5mm plasterboard on dot & dab internal finish.
  • Overall wall thckness (excluding internal finishes) of 300mm max.
  • A 50mm clear cavity in the case of partial-fill cavity constructions.
Please contact us if you require a specific u-value calculation performing that does not appear on either of these tables.
 
 

Partial Fill Cavity Walls

Full Fill Cavity Walls

 
 
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Note:
These u-value figures are intended for indicative purposes and calculations are made in good faith, wholly based on the thermal data of insulation materials and blocks available at the time of writing. However, the thermal properties of these materials can be changed by the manufacturer without prior notice. Details, practices and principles should always be verified by the recipient or his client as to the accuracy and suitablility for the intended purpose. Thomas Armstrong Ltd shall not be held liable for any incidental or consequential damages arising out of the use of this report. We always advise that a second opinion be sought through a qualified and approved body prior to approval of the construction based on the figures herein.