First the existing brickwork was cut out allow the new internal skin to join the existing internal brickwork, this maintains the cavity and stops the cavity being bridged which cause damp problems. Wall starters were then fixed to the existing brickwork. We prefer to use “Wall Starters” rather than physically teething into the brickwork because the brick size, the gauging on the existing brickwork is not consistent and if there is any settlement the toothed bricks are likely to break which would be a costly repair. Where as if settlement occurs and wall starter are used there is no damage as the straight joint where the 2 walls meet should be filled with a flexible water proof sealant. Anyway………………..
The openings and bond were set out and profiles installed.
The next job was install the damp proof course (DPC) and cavity tray. The damp proof membrane (DPM) / Radon Barrier from the slab is brought through to the outer skin of brickwork, a block is then laid on the inside skin. Next a 450mm wide DPC is laid on the brickwork lapping up to the next block course creating a tray, another block is laid on the inside skin. Next a course of bricks is laid over the DPC and a weep outlet placed in a joint every 1.5m
The brickwork then proceeded, building the outer skin 1st then “backing it up” with the blockwork installing the cavity insulation as work progressed. The lintels were bedded on and another cavity tray install exactly the same as on the DPC. The wall plates were bedded on the blockwork at the correct height and the brickwork to the gables continued building in the 1st floor window profiles and install the lintels. The brickwork to the Gables could not to finished until the roof is cut, however the cavity closers were install the the openings, it is good practice to keep the brickwork, blockwork and cavity dry.
Terry J
www.atj-builders.co.uk
