Being in a very popular residential area of Leicester the main challenge was the proximity of the neighbouring houses and the restricted access to the site for heavy plant and deliveries.

Protecting excavation banks from collapse for the team belowFoundations for building above linked to basementStrip foundations for main buildingFoundations for the rest of the building joined to the basement wallsBasement walls thicker in places for extra support for the building aboveTwo sections of walls meetingFinished concrete wallsLarge pump devlivering concrete to the wallsSteel bars at the top of the wall "closing" the concrete, reducing crackingShutters supported by steel props during pourDivy bars giving support to shuttersWall poured in two sections with steel joined for continuityWall reinforcingShutters stripped off and divy bar wholes filledExternal wall shutters being supportedChange in levels at the top of the wallConcrete filled to top level of shuttersConcrete being vibrated during pour to ensure full coverage of steelScaffold to support the team working at heightSteel reinforcing the walls, linked below to the slab steel barsSteel props supporting wallsWalls fully built and supportedScaffold erected to allow team to work in safetyWalls ready for concreteWalls supported internally during concrete pouring with steel propsDivy bars joining both sides of twin soldiers to give support to walls during concrete pourWalls supported internally with two large vertical timbers known as twin soldiersSteel bars going through both sides of the shuttering to join them togetherWalls reinforced with steel bars linked to steel coming through the kicker from the baseWalls constructed with shuttering both sidesWalls being shuttered with large shutter pansKicker construction for all wallsKicker construction with central timber to allow for installation of an expanding water stopKicker construction is attached to the main shuttering to allow continuous construction without joints in the concreteThe basement slab includes the first 150mm of walls, called a kicker, to move the waterproofing point of weakness higherPipe work for sumps and bathrooms installed through the steelReinforcing around sumps to reduce crackingTwo layers of steel are laid to give maximum strength to the concrete basePermanent external sump to allow for clean and dry working area throughout the buildSteel reinforcing laid out in layers to allow it to be built upTimber shuttering setting out the basement outlineGround water sump installed within basement for the internal waterproofing systemReinforcing for the floor built up in layers to give maximum strengthReinforcing bars set out using string lines to allow continuity with the wall reinforcing aboveMain flooring base set out with timber shutters and reinforced with pre-bent steel barsPipe work for bathroom installed under main concrete base reinforcingFoul sump installed to allow for connections to basement WC & showerPermeant, maintainable land drain installed at the base of the excavation to keep central area dry and allow a clean working areaExcavation carried out in phases to allow the team to secure the banksEarth banks kept constantly wet to prevent drying, cracking and collapseExcavation sides are angled at 45 degrees to prevent dangerous collapses

Build Method

On this project Beautiful Basements was asked to design and build the basement. The best option for this project was to create a reinforced concrete (RC) basement, and have the rest of the house built using that as the foundation.

The basement was built using mass filled concrete between temporary timber shuttering with concrete containing a waterproof additive.

Once the basement had been complete and back-filled with a layered, compacted, granular material, the adjoining foundations for the rest of the new house were built and tied into the sub-structure with reinforcing steel to avoid any movement and give more strength to the super-structure.

Waterproofing Method

  1. Type B – Intergral Protection. The basement was constructed using reinforced concrete with an additive, making the concrete waterproof. All external construction joints, the RC wall kicker & slab toe were treated with a waterproof cementitious waterproofing slurry, giving extra protection to the Type B system.
  2. Type C – Internal Cavity Drainage System. The internal walls and floor were lined with a cavity membrane, all linked to a sump and pumping station via perimeter channels. Two pumps and a high level alarm were installed.

 

All materials were supplied by Triton Systems.

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Location: Oadby, Leicester
Completed: 2017