Use a cavity tray if masonry above ground, It is a common design fault to finish the basement wall beneath ground level allowing Cast a ledge board in place of a waterproof concrete for 600mm if Polarwall. water in over the top; usually because block and beam is chosen for this internal floor Polarwall panel and support level. engineered timber beams on If beam and block is used, see the alternative details. Polarwall is available (as standard joist hangers casting Engineered truss floor standard) in 4 concrete widths so steps and upstands are fairly simple. Fill the ends of waterproof concrete (with beam and block with waterproof mortar and over paint with Elasto Cover and continue waterproof joints) up to well well down the face of the upstand. Where Polarwall is not used above the basement, it above ground level. would be better to extend the upstand alongside beams up to the top of beam level. Traditional brickwork can be (Note: The wall is only 'retaining' below ground and built off a ledge as shown Plasterboard The upstand is poured in one. No joint. retaining very little at the top where it can be thinner. (which can vary in height as the 'Propped' cantilever floors are a bit complex, ask the Studwork to protect membrane, house ground level changes). Render, structural engineer for a cantilever design. services and contain insulation siding or brick slips are also used to decorate Polarwall. Internal drained cavity membrane Water management membrane, with geotextile filter, if external drainage is used. Note: Perforations through the wall, such as soil pipes, can have a twisted In general we use waterproof concrete with external drainage where rope of Denso tape wrapped round to create effective puddle the ground drains or internal drainage membrane where it might not. flanges. Where we use internal drainage, we can expose one face of the water- proof concrete, inspect it and repair it as deemed necessary on site. This can be either the inside or the outside face. The other side will Other ground level details have polystyrene formwork remaining as insulation. Extra insulation can be put within internal studwork later. are shown on two other Options include chiselling out poor concrete and joints and refilling with After the wall is poured expose the drawings. sharp sand mortar waterproofed with Compact All Civil; applying WPL joint and remove any poor waterproof render over the top; painting or spraying 3 coats of Elasto concrete. Replace with sharp sand Cover liquid membrane. mortar waterproofed with Compact All Civil. This can be either side or Careful consideration is to be given to the susceptibility of the repair to both sides as appropriate on site. damage by groundworkers when backfilling and compacting. Elasto Cover compressible liquid Please note that the Elasto Cover membrane and the membrane poured or brushed on Screed Compact All Civil concrete mortar repairs may be either at least 1mm thick in 3 layers. under or against any part of the wall where they do not Insulation Polystyrene replaced as necessary. interfere with the design of the structure. Working room, Internal drained cleanliness, water and weather, size, spacing and position cavity membrane of steel will influence this choice uniquely on each site. Structural slab c Newmil Buildings Ltd sump Perforated pipe to soakaway. Wrapped in geotextile All branded products available from Concrete waterproofed membrane and surrounded with pea shingle also Waterproof Concrete Ltd with Compact All Civil wrapped in geotextile membrane. www.waterproofconcrete.co.uk If external drainage is relied upon, the drainage should be designed to work in all seasonal and weather conditions and for Drawn by PCS the lifetime of the building. Landscape the ground to slope away from the basement. Overall system of Not to scale Have 2 soakaways well apart, one for roof water and the other just for the basement. Be mindful of soil draining characteristics. waterproofing January 2008 Make all drainage roddable. Wrap everything in geotextile filter. basements Revision: E Wall concrete needs to be delivered into the wall properly through a pipe threaded to within 1200mm of the bottom. The pipe will need to be smaller than the concrete pump’s boom pipes so a reducer is needed. Ensure readymix concrete is available with 10mm aggregate within a 40 minute journey time before choosing our solution. Unfortunately volumetric mixers cannot be used because they cannot mix in the Compact All Civil.