HOW IS MY HOME BUILT ?

20.09.2019

It always surprises me how little most people know about how the home they live in is built. It amazes me even more that some people spend thousands of pounds on one without it being inspected by a surveyor who does know how its built, – and the potential strengths and weaknesses of the construction. So let’s have a brief look at the main building types locally.

Most flats and houses in our area are one of four construction types, – solid brick, cavity, timber frame and system built. How can you tell the difference? The usual signs are in the outer walls. Most older buildings in our area, from Georgian houses and Victorian cottages through to Tudor style 1930s houses, are solid brick and usually have what we call ‘header and stretcher’ walls. The bricklayer has laid the rows of bricks at right angles, so from the outside you see the short end of a brick (the header) next to the long side (the stretcher). Usually these are laid alternately in a pattern known traditionally as ‘Flemish Bond.’ Sometime locally you also see alternating rows of headers and stretchers in a solid wall which is known as English Garden Wall Bond.

After the war, we generally moved to cavity construction where there are actually two walls – the outer and inner leaf, with a gap (the cavity) between them. Originally this was to prevent damp travelling through the wall, so cavity walls developed later in our area than wetter parts of the UK. The outer cavity wall is typically in a ‘stretcher only’ pattern, with all the bricks laid on their longer edge. In early cavity walls, both leaves were often brick, but later on the inner leaf was typically built with cheaper blocks. The change from solid brick to cavity can be traced in local authority housing in Ham and Petersham. Older examples in, say, Mead Rd and Stretton Rd are solid brick, but post war flats and houses like Beaufort Court, Meadlands Drive and Petersham Close have thicker cavity walls. Some roads have pre-war solid brick houses with later post war cavity walls houses. My own personal favourites are the flats in Stuart Road which very unusually have header and stretcher walls on the ground floor and stretcher only walls on the upper 2 floors!

Modern timber frame construction also has stretcher only exterior walls but the outer wall is basically cladding with little supporting role. The main load is on the inner timber frame. Sometimes it’s hard to tell whether a building with a stretcher only wall is a cavity wall or cladding but there are often tell-tale signs. A cavity wall often has ‘weep holes’ to let out moisture or has drill holes under the window where it’s been filled with insulation. The exterior of a timber frame looks more uniform, the windows are often recessed and sometimes it’s not even been built of bricks at all, it may just be panels that look like bricks. Sometimes I can only definitively tell by inspecting the loft where you may see either the exposed timber frame or the inner blockwork leaf of the cavity.

But many local buildings don’t exclusively have one wall type. From the 1920s, many bays have rendered or tile hung frames between the windows, not solid brick. Many houses and maisonettes on the Wates estate in Ham have all three types of wall in a single unit! Like other local developments such as Parkleys, these hybrid types emerged from the trend for ’cross wall construction.’ The load of upper floors and roof is carried on the front-to- back cross walls and end walls. An end terrace Wates 2 storey house may have a solid end wall, a mainly timber frame front and rear, but sections of cavity wall under the lounge window and kitchen window. Many Wates maisonettes have timber frame front walls, rear cavity walls and solid party walls. To support the load across a whole terrace, some end walls are actually very thick – up to 18’’ (2 bricks) thick (when a normal 9’’ solid wall is only 1 brick thick).

The 50s and 60s saw more esoteric ‘system building.’ The 1960s Ham Close flats are ‘Wimpey No Fines’ construction, so called because the walls were formed of poured concrete with no fine aggregates in it. Maguire Drive were ‘Unity’ construction and some former wardens houses in Latchmere Close are ‘Cornish Units’ where originally ground floor walls were concrete panels with a timber frame mansard 1st floor. System building has gained traction again in MMC (modern methods of construction.) Some modular flats and houses are factory built and assembled on site. Things have moved full circle from the prefabs which housed many Ham residents after the war to the contemporary prefabricated Huf Hauses  recently built in Ham Street. The more things change, the more they stay the same!