BISF House Cross Sectional Diagram
For those members asking to see plans, here we have a cross-section diagram of a typical British Iron & Steel Federation (BISF) house. The view provided is looking toward the side elevation of the house from the direction of the gable wall, and it has been drawn as if the house had been sliced in half.
The main structure of the BISF house is of steel columns evenly spaced in order facilitate the fitting of standard sized, Crittal Hope metal windows which are attached in between the steel columns. The central spine of the building which supports the first floor beams is carried on tubular steel columns. The framework is clad on the lower storey with rendering on metal lath. The outer cladding of the upper floor is of steel trussed sheeting fixed by angles to the steel columns. The inner cladding and the partitions are constructed of timber framing faced with plasterboard or hardboard. Floors are of timber and the ceilings are finished with plasterboard or fibreboard.
You can clearly see the location of the steel frame and supporting joists in light great. This diagram also provides a side view of the strip foundation footings on top of which sit concrete filled brick or block columns.
The frame of the house is effectively then bolted down onto the concrete slab using large anchor bolts located at the bottom of each steel column or stanchion.
A glass fibre insulation quilt with paper lining fills each wall cavity and although poor in quality compared to todays modern fibres, they do manage to insulate the property to a higher level than normally expected. In part this insulation works well when combined with the lathed concrete render and the formulation of cement mix used during construction. However where the insulation is fitted behind the pressed steel outer wall panels of the first floor, the fibre insulation performs very poorly indeed.
You may also find that differing insulation may have been used in your loft space. Anything from glass fibre to shredded paper. Care should be taken to identify the loft insulation that you have installed in your home as various products were used Post War contractors that may contain asbestos.
We have not found asbestos loft insulation in any of the properties that we have examined, however this is not to say that it has never been used in BISF construction.
Asbestos insulation can take on many different forms with some even resembling vermiculite as shown below.
It should be noted that insulation containing asbestos can be found in all pre & post war houses no matter what the construction type. It is not specific to the BISF house and can even be found inside houses built during the 1970’s.
If you are at all in doubt, always contact an approved asbestos specialist who will be able to examine any suspicious material found.