Insulation for Timber Joist Internal Floors
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Start your U-value calculation >The primary purpose of an internal floor is to provide acoustic separation for airborne sound between two adjacent rooms within a dwelling, thereby improving the acoustic comfort of those within the dwelling.
These floors are typically constructed using solid timber joists or timber I-beams with a minimum 18mm thick timber floor deck laid above the joists and a plasterboard finish applied below the joists.
The insulation of choice for internal floors is typically a glass mineral wool (GMW) roll or slab. ISOVER products can be installed as part of the internal floor construction between the joists/I-beams to provide the level of sound reduction required according to Approved Document E (England & Wales) and Section 5 (Scotland).
The building detail is for illustrative purposes only. It does not constitute advice and should not be relied upon.
Insulation products
| Product Name | Thickness Range | Sizes | Lambda | BBA |
|---|---|---|---|---|
| ISOVER Acoustic Partition Roll (APR 1200) | 25-100mm | Width 2x600mm, Length 9170mm-20000mm | NA |  |
| ISOVER Acoustic Slab | 50-100mm | Width 600mm, Length 1200mm | NA | |
| ISOVER Unislab | 50-140mm | Width 400mm or 600mm, Length 1200mm | 0.036 W/m.K | |