Partially separate system Drainage inspection chamber f.w.g. s.v.p r.w.p f.w.g. s.v.p r.w.p foul water sewer foul and surface water sewer f.w.g r.w.p r.w.g surface water sewer f.w.g r.w.p r.w.g Combined system Separate system f.w.g. s.v.p r.w.p foul water sewer surface water drain r.w.g f.w.g r.w.p Partially separate system soakaway or drainage ditch (alternative surface water discharge) Below ground drainage From Plumbing (3rd edition), R.D. Treloar, page 329 Copyright Blackwell Publishing Ltd, all rights reserved: www.blackwellpublishing.com

Drainage Protection of pipework Key Bedding for rigid pipes G/L G/L 200 mm 150 mm min 100 mm 100 mm class ‘f’ bedding class ‘b’ bedding 100 mm Key Bedding for rigid pipes Bedding for flexible pipes flexible joints soil arch or lintelled opening 50 mm space around pipe granular material 600 mm max 600 mm max 150 mm rigid sheet material 150 mm Drains penetrating a wall selected fill with no stones largers than 40 mm selected fill with no lumps of clay, large stones or frozen and vegetable matter Pipes run close to the building concrete Protection of pipework From Plumbing (3rd edition), R.D. Treloar, page 331 Copyright Blackwell Publishing Ltd, all rights reserved: www.blackwellpublishing.com

Drainage Gullies and traps Anti-flood gully Trapped gully copper float galvanised sediment bucket waste pipe gully hopper gully trap bronze flap cork float Anti-flood gully Trapped gully ‘Eureka’ trunk valve (valve open) Garage gully perforated tray stopper Trapless gully dosing point outlet baffles Grease trap trap rodding access intercepting trap inlet Grease converter Gullies and traps From Plumbing (3rd edition), R.D. Treloar, page 333 Copyright Blackwell Publishing Ltd, all rights reserved: www.blackwellpublishing.com

Drainage Provision for access Inspection chambers access cover rodding point inspection cover Access door of soil pipe access covers cut to the required height benching plastic chamber channel Inspection chambers brick built chamber Provision for access From Plumbing (3rd edition), R.D. Treloar, page 335 Copyright Blackwell Publishing Ltd, all rights reserved: www.blackwellpublishing.com

Back-drop connections Connections to existing systems Drainage block inserted in the upper half to minimise surcharging saddle junction junction block benching 2:1 sand–cement encased in concrete open channel 0.68 mm max access bend Ramp cast iron or plastic pipe within chamber access point clayware encased in concrete benching rest bend drain at lower level Back-drop connections Connections to existing systems From Plumbing (3rd edition), R.D. Treloar, page 337 Copyright Blackwell Publishing Ltd, all rights reserved: www.blackwellpublishing.com

Drainage Determining drainage levels timber plank 25 mm 1 mm spirit level cut as shown to make a Gradient board to a fall of 1:40 traveller sight rail gradient board branch drainage pipe operative sighting between sight rails and instructing colleague to raise or lower the pipe bedding material operative removing or inserting bedding material to raise or lower the pipe. fall of drainage run sight rail sight rail water pipe level plain Laser level drainage pipe traveller bedding material From Plumbing (3rd edition), R.D. Treloar, page 339 Copyright Blackwell Publishing Ltd, all rights reserved: www.blackwellpublishing.com Determining drainage levels

Drainage From Plumbing (3rd edition), R.D. Treloar, page 341 Copyright Blackwell Publishing Ltd, all rights reserved: www.blackwellpublishing.com

Drainage Eaves guttering Gutter designs rafter bracket side fixing (used where there is no fascia board) side fixing top fixing rafters fascia bracket running outlet down pipe fascia board 1 m max amount of fall string line plan area 4.0 m 6.0 m L half round square line B Gutter designs 5.0 m ‘O Gee’ 45° effective area for calculation purposes: 6 m x 4 m x 1.4 = 33.6 m2 Eaves guttering From Plumbing (3rd edition), R.D. Treloar, page 343 Copyright Blackwell Publishing Ltd, all rights reserved: www.blackwellpublishing.com eaves

Selection of rain water and gutter fittings Drainage Selection of rain water and gutter fittings From Plumbing (3rd edition), R.D. Treloar, page 344 Copyright Blackwell Publishing Ltd, all rights reserved: www.blackwellpublishing.com

Rainwater connections to discharge stacks Drainage gutter rainwater hopper head gutter offset formed 2 m max pipe bracket adaptor to drain pipe roof outlet vent roof decking plumb bob shoe combined roof outlet and vent pipe Rainwater connections to discharge stacks Rainwater pipes From Plumbing (3rd edition), R.D. Treloar, page 345 Copyright Blackwell Publishing Ltd, all rights reserved: www.blackwellpublishing.com

Soakaways, cesspools and septic tanks Drainage surface water drain concrete slab support irrigation trench rodding access outlet inlet hardcore or clinker filled soakaway (limited storage capacity) dry wall soakaway (good storage capacity) baffle Soakaways GRP septic tank 100 mm dia vent inspection covers house drain partition baffle fresh air inlet 3 m minimum inspection cover rodding access crust formation dip pipe inlet dip pipe outlet irrigation trench inlet the anaerobic bacterial action only occurs when a crust has formed on the surface hence the need for dipped inlet and outlet pipes sludge Traditional brick built septic tank GRP cesspool Soakaways, cesspools and septic tanks From Plumbing (3rd edition), R.D. Treloar, page 347 Copyright Blackwell Publishing Ltd, all rights reserved: www.blackwellpublishing.com

Soundness testing of drainage systems jointing material etc., causing a blockage unaligned pipe Obstruction test ball (13 mm less in dia than pipe) reflected light should reveal a perfect circle mirror torch Reflection test 4.0 m max head 15 mm or 1/2’’ BSP mild steel pipe 1.5 m min head drain plug or bag Water test 100 mm valve closed during test hand pump drain plug drain plug Air test Soundness testing of drainage systems From Plumbing (3rd edition), R.D. Treloar, page 349 Copyright Blackwell Publishing Ltd, all rights reserved: www.blackwellpublishing.com