Insulation between joists
Insulating between the joists of a suspended timber ground floor or roof can help to improve your building’s thermal efficiency and reduce noise transmission. It is particularly suitable for older homes and other buildings where thermal efficiency is paramount. STEICO’s wood fibre insulation can be used to insulate between joists of a suspended timber ground floor or roof in most buildings.
What do we mean by insulating between joists? And how is it installed?
The free movement of air underneath a suspended timber ground floor or above the insulation in the loft is important to keep the timbers from rotting due to a build-up of condensation. However, it also creates the potential for draughts that would cool a home and make it less thermally efficient.
Heat loss through the floor and roof can be significant in homes of all sizes, so a solution was needed to ensure ventilation without the home as a whole suffering. Insulating between joists in a suspended timber ground floor or roof is the answer.
There are two main methods of installing insulation between joists, from above and from below:
- From above in the loft – This is a case of going up into the loft and cutting insulation to fit in the gaps between the existing joists. It is then fit snugly into places, and any gaps are filled in. If you want to install a flooring system in your loft, it can be done following the installation of the insulation between the loft joists.
- From above in a suspended timber floor – Ideally this should be done before the floor is boarded and top layers are installed. Insulation should be cut to size to fit snugly between the joists, then secure in place using battens. The floor surface layers can then be installed as normal.
- From below in a suspended timber floor – If you want to install from below in the roof or floor, you should first make sure that the flooring boards are installed above. Then, push the insulation boards into place between the joists and install battens to hold them in place.
With either installation method, you should ensure that gaps are filled, and a vapour control layer is also installed to help prevent moisture build up that could affect the insulation and the timber.
The potential benefits of insulating between joists
Insulation between joists in your roof or suspended timber ground floor can offer a range of potential benefits when the system is specified and installed correctly, including:
- Energy efficiency – Additional insulation can reduce heat transfer through the floor or roof and improve the thermal efficiency of your building.
- Sound insulation – Insulation can also reduce sound transfer between floors or through the roof for improved comfort in the home.
- Space savingoption – If you insulate between the joists in your floor or loft space, you won’t lose any floorspace in the home like you can with other types of insulation.
- Protect floor structure – Insulating between the joists of a suspended timber ground floor or loft allows you to maintain air flow so that moisture build-up is still controlled and the timbers are protected.
What makes STEICO wood fibre insulation boards a good option for insulating between joists?
STEICOflex wood fibre flexible insulation batts are suitable for insulating between the joists in a suspended timber ground floor or loft space, and can offer a number of benefits, including:
- Wood fibre structure – The product is made from wood fibres which can help prevent mould and moisture damage when specified and installed correctly thanks to their diffusion-open structure.
- Easy to modify and install – STEICO interior insulation can be modified using standard tools for ease of installation on site.
- Bulk density of approximately 50kg per cubic metre which can help you meet your required acoustic rating.
- They bind 82kg CO2eq during Life Cycle Stage A1 as defined in EN 15804+A2 and can potentially help reduce energy needs once the building is in operation.
- Responsible sourcing – STEICOflex is manufactured from PEFC certified timber (PEFC/04-31-2550) which is fully recyclable at the end of its life.
