Specification by Period

Specification Notes

Foundations - No real changes since 1985 example. Most houses have concrete strip foundations 500 to 600mm wide and about 1000mm deep in clay, slightly less in firm sand or gravel. Depending on circumstances foundations can be traditional strip or trench fill. Houses built on brownfield sites etc may have piled foundations. These can be driven or augered depending on the nature of the ground.  Some houses, in former mining areas for example, may have specially designed raft foundations. Walls below ground level can be either aerated concrete blocks or dense blocks. Where a house has an internal loadbearing wall supporting the first floor joists slab thickenings were sometimes provided rather than a 'proper' foundation.

Walls - Cavity wall construction with brick, stone or artificial stone in the outer leaf and aerated blocks in the inner leaf. The inner leaf may be 130mm or even 150mm to achieve the appropriate U value (0.35 in 2005).  Cavities from this period are normally 75 to 100mm wide. Most cavities include insulation in the form of fibreglass batts or insulation board. Wall ties mostly stainless steel or galvanised ties with Agrement certificate. Mortars were cement based (OPC or masonry cement); sometimes mixed on site, sometimes partly pre-mixed mortar (containing sand, lime and pigment), and sometimes pre-mixed cement mortar with a retarder.  Walls mostly finished with drylining, either on dabs or screwed to metal channels bedded in adhesive. Two coats lightweight plaster still found - often Thistle Browning and Thistle Finish.

Windows - Plastic windows common, double glazed and fixed with straps to inner reveal or with extruded plastic cavity closers. Window boards were usually MDF, lintels usually galvanised steel (sometimes with separate cavity trays). Box section lintels include insulation. 

Roofing - Trussed rafters almost universal with bracing, binding and strapping. Bracing of lower truss members common - particularly in areas of high winds or where there is no ceiling finish. Vapour permeable underfelts common. Most roofs ventilated at eaves. 200mm roof insulation. Ceilings usually 15mm plasterboard screwed to resilient bars. Ceilings were usually taped and painted.  Roof coverings often through-coloured concrete interlocking tiles or concrete plain tiles. Synthetic slates (various types) also popular.  

Ground Floor - Floating chipboard floors on pre-cast beam and block or power-floated Jet floor common. Ground bearing slabs fairly rare. All ground floors insulated. 

Upper Floor - Softwood joists on hangers (joists rarely built-in because of air leakage) or metal web joists on hangers. Floors strutted with herringbone struts, joist off-cuts or proprietary struts. Strapping to external walls every 2 metres. Floors mostly covered with tongued and grooved chipboard (screwed) or strand board. Soffits finished with resilient bars and 15mm plasterboard (screwed) or 100mm quilt and 15mm plasterboard. NB No noggings required with 15mm plasterboard.   

Internal walls - 100mm dense blocks or aerated for loadbearing partitions; 75mm aerated blocks for lightweight non-loadbearing block partitions.  Door linings screwed in position. Plasterboard, self-finished partitions, - laminated, timber stud and Gypwall (metal stud) the three most common. Sound quilts in stud partitions.

Services - Approximately half of all new boilers are 'Combis', and system boilers also common (pressurised boiler like a combi but supplies a hot water cylinder). Copper and plastic pipework both common - often with push-fit joints. Plastic tanks and copper hot water cylinders. Room thermostat and TRVS the norm. Electrical installations with MCB consumer unit. External sockets with RCD protection. Drainage systems mostly separate with vitrified clay pipes or plastic pipes, both with flexible connectors. Above-ground drainage all plastic (push fit or solvent welded). Inspection chambers concrete ring or plastic; chamber covers mostly galvanised steel or bitumen coated steel in gardens, cast iron in roads.