What is a sub-frame for?

What is a sub-frame for?

10:48 16 March in

Sub-frames are basically a supporting frame under the boarding to allow the boarded area to be raised above the insulation and/or for adding better support and strength.


See examples below of different sub-frames we use to create a safe, strong storage floor in your loft.


We offer the following types of Sub-frame. Standard Trussed for new builds back to around 1960’s called LOFT-E and LBNW Timber Raised and Supported for older purling style roofs circa 1960’s and older.


Any loft that has any insulation protruding above the joists, will require a sub-frame of some kind to suit the joist type before boarding.


Boarding directly onto your joists by removing or squashing insulation is bad practice nowadays. If you’re boarding your own loft, follow the advice given on our website and if you choose another company to do it, make sure they are doing as advised here. If you are not confident in what another company describes or proposes to do, contact us for free advice on 01254 370073.


Your insulation and loft need to have airflow. Stopping air circulation in lofts by boarding all of your loft or blocking eaves, roof or soffit vents can cause problems like condensation build-up, which may lead to damp ceilings and loft timbers. Do not squash insulation down, and if you use a sub-frame above your insulation, do not box in the ends so that air can pass underneath your storage floor and through the insulation so it can work efficiently.