Renovation 4th Edition

by Michael Litchfield

  cast iron; you could use similar

  couplings to splice aBS or PVC

  drainpipes to cast iron.

  338 Chapter 12

  Run clear water through the drains before

  cutting into them. Flush the toilets several times

  and run water in the fixtures for several minutes.

  Then shut off the supply-pipe water and post

  zzzzzz vent Termination

  signs around the house so people don’t use the

  fixtures while work is in progress.

  splICIng a BranCh

  DraIn InTo a sTaCk

  12 in. minimum

  If you’re adding a toilet, have a plumber calculate

  6 in. minimum

  the increased flow, size the pipes, recommend fit-

  10 ft. minimum

  tings, and—perhaps—do the work. Adding a lav,

  sink, or tub, on the other hand, is considerably

  easier and less risky—mostly a matter of splicing

  3 ft. minimum

  a 11⁄2-in. branch drain to a 2-in. or 3-in. stack.

  The basic steps are clamping the stack before

  Roof flashing

  cutting it, inserting a tee fitting into the stack,

  and joining the branch drain to that fitting.

  Windows open.

  Let’s look at splicing to a cast-iron stack first.

  Start by holding a no-hub fitting (say, a 2 by

  11⁄2 sanitary tee) next to the stack and using a

  grease pencil to transfer the fitting’s length to the

  stack—plus 1⁄2 in. working room on each end.

  So vent gases won’t enter the home,

  (This gap at each end will be filled by a lip inside

  plumbing vents must terminate at

  the neoprene sleeve.) Install a stack clamp above

  least 3 ft. above an openable window,

  and below the proposed cuts. Then use a snap

  or a minimum of 10 ft. horizontal

  distance from an openable window at

  the same level.

  A CAST-IRON STACK

  AN ABS-PLASTIC STACK

  zzzzzz splicing a Branch Drain to a stack

  Slip-coupling or

  1

  Stack clamp

  no-hub coupling

  2x cleats

  Short length of

  nailed to studs

  plastic pipe glued in

  Cast-iron

  no-hub fitting

  4

  1 in. more than

  length of fitting

  3

  5

  2

  ABS

  No-hub coupling

  reducing tee

  4

  Neoprene sleeve

  ABS stack

  3-in. or 4-in.

  cast-iron stack

  Stack clamp

  1. Using stack clamps, support the stack above and below

  Glue two short lengths of ABS pipe to a tee. Mark an equivalent

  the cuts. Mark and cut the stack. 2. Slide no-hub couplings

  length plus 1/2 in. on both ends onto the ABS stack to indicate

  onto cut stack ends (you may need to roll the neoprene

  cutlines. (Each ABS slip-coupling has an inner lip that nearly

  sleeves on first). Insert a no-hub fitting. 3. Slide couplings

  fills the 1/2-in. space). Support and cut the stack. Finally, join

  over fitting ends. 4. Tighten. 5. Connect the branch drain

  the pipes by slipping the couplings in place.

  to the no-hub fitting.

  plumbing

  339

  cutter to make the two cuts. Drill through studs

  diameters, to tie the new 11⁄2-in. plastic branch

  as needed to run the branch drain. Next, slide no- drain to the cast-iron no-hub coupling.

  hub couplings onto both cut pipe ends; in most

  Tying into an ABS or PVC stack is essentially

  cases, it’s easiest to loosen the couplings, remove

  the same, except that you’ll use a wheeled cutter

  the neoprene sleeves, roll a sleeve halfway onto

  to cut the stack. And, instead of using a no-hub

  each pipe end, and then replace the couplings.

  coupling, glue short (8-in.) lengths of pipe into

  Insert the no-hub fitting, unroll the sleeves

  the tee fitting, then use plastic slip couplings to

  onto fitting ends, slide the banded clamps over

  join the 8-in. stubs to the old pipe. (The slip cou-

  the sleeves, orient the fitting takeoff, and tighten

  plings also glue on, with an appropriate solvent-

  the clamps with a no-hub torque wrench. Finally, based cement.) Use a reducing tee, such as a 2 by

  use a transition coupling, which is a special no-

  11⁄2. Be sure to support the stack above and below

  hub coupling that accepts pipes of different outer before cutting into it.

  BuIlDIng ouT

  From The maIn DraIn

  3-in.

  Extending the DWV system out from the end of

  zzzzzz extending a Cast-Iron main Drain

  soil stack

  a cast-iron main drain—where it joins the soil

  3-in.

  stack—can be the least disruptive way of tying in

  main drain

  Cleanout

  a new drain if there’s a cleanout at the end of the

  If you build out from a cleanout,

  main drain that you can remove. Before cutting

  you must install a new one at

  into existing drains, however, support both sides

  the end of the extension.

  of the section to be cut, using pipe clamps or

  strap hangers.

  Combo fitting

  The exact configuration of the end run will

  depend on the size of the main drain, the fitting

  currently at the base of the stack, the fixtures

  you’re adding, and the size of the drain needed to

  Stack

  serve them. If you are not adding a toilet, the

  3-in. main

  3-in. cast iron

  drain extension can be 2-in. pipe, which can be

  attached with a reducing bushing such as the

  3-in. ABS drain

  male-threaded adapters shown in “Extending

  with 2-in. ABS” at left. If you’re adding a toilet,

  however, the extension must be 3-in. pipe, often

  inserted with a ribbed bushing to ensure a tight

  fit. If it’s not possible to insert the 3-in. pipe into

  Transition coupling

  an old cleanout leg, you may need to cut out the

  existing combo and install a no-hub combo to

  EXTENDING WITH 3-IN. ABS

  If the present cleanout is a cast-iron inset caulked with oakum,

  build out from.

  remove the oakum and the inset and replace it with a short section

  Note: If you build out from an existing clean-

  of 3-in. cast-iron pipe. From there, use a transition (no-hub) coupling

  out at the end of the main drain, you’ll need to

  to continue with 3-in. ABS plastic.

  add a new cleanout at the end of the extension.

  TyIng InTo The

  Stack

  maIn DraIn In mIDrun

  2-in.

  3-in. main

  MIP adapter

  Before tying into the main drain in midrun, flush

  the drain and support both sides of the section

  you’ll cut into. Then install strap hangers to sup-

  port both sides of the 3-in. or 4-in. drain. Tying

  into a cast-iron or plastic drain is essentially the

  same procedure as splicing into a stack, but it
<
br />   requires different fittings. With one hand, hold

  Threaded cleanout

  2-in. ABS drain

  Cleanout

  the no-hub combo fitting you’ll add next to the

  drain section, and with the other hand, mark cut-

  EXTENDING WITH 2-IN. ABS

  lines onto the drain using a grease pencil. The cut

  If there’s presently a threaded cleanout opening and you are adding a

  marks should be 1 in. longer than the length of

  tub, lav, or sink—but not a toilet—use a plastic MIP (male iron pipe)

  the fitting to accommodate the thickness of the

  adapter.

  stop lip inside each no-hub coupling’s neoprene

  340 Chapter 12

  Framing for Toilets

  and Tubs

  you may need to cut through joists to

  accommodate the standard 4 by 3 closet bend

  maximum sizes for holes and notches

  beneath a toilet or the drain assembly under a

  standard tub. In that event, reinforce both

  FRamINg eLemeNT

  HoLe dIameTeR (in.)

  NoTcH dePTH (in.)

  ends of severed joists with doubled headers

  attached with double-joist hangers. This

  Bearing studs

  beefed-up framing provides a solid base for the

  7

  toilet as well. If joists are exposed, you can

  24

  

  13⁄8

  ⁄8

  also add joists or blocking to optimize support.

  26

  

  23⁄16

  13⁄8

  Toilets. a minimum 6-in. by 6-in. opening

  Nonbearing studs

  provides enough room to install a no-hub closet

  bend made of cast iron (41⁄2 in. outer diameter)

  24

  

  2

  13⁄8

  or plastic (31⁄2 in. outer diameter). The center

  2

  of the toilet drain should be 12 in. from a fin-

  6

  

  31⁄4

  23⁄16

  ish wall or 121⁄2 in. from rough framing. If

  solid lumber joists

  joists are exposed, add blocking between the

  26

  

  13⁄

  7

  4

  ⁄8

  joists to stiffen the floor and better support

  the toilet bowl, even if you don’t need to cut

  28

  

  21⁄2

  11⁄4

  joists to position the bend.

  2

  Bathtubs.

  10

  

  31⁄

  a 12-in. by 12-in. opening in

  8

  15⁄8

  the subfloor will give you enough room to

  212

  

  33⁄4

  17⁄8

  install the tub’s waste and overflow assembly.

  Ideally, there should be blocking or a header

  close to the tub’s drain that you can pipe-strap

  The toilet drain. After framing the toilet drain

  P R O T I P

  it to. To support the fittings that attach to the

  opening, install the 4 by 3 closet bend, centered

  shower arm and spout stub-outs, add cross

  12 in. from the finished wall behind the toilet.

  braces between the studs in the end wall. To

  If the neoprene sleeve inside

  Install a piece of 2x4 blocking under the closet

  a no-hub coupling won’t slide on

  support tub lips on three sides, attach ledgers

  bend, and end-nail through the joists on both

  easily, it may have a small stop

  to the studs, using galvanized screws or nails.

  ends. Use plastic plumber’s tape to secure the

  lip inside—sort of a depth gauge

  Finally, if there’s access under the tub, add

  bend to the 2x4. What really anchors the closet

  to stop the incoming pipe in the

  double joists beneath the tub foot.

  bend, however, is the closet flange, which is

  middle of the sleeve. soap the

  cemented to the closet bend and screwed to

  inside of the sleeve to reduce

  the subfloor.

  friction. you could use a utility

  The flange is screwed to the subfloor, yet it

  knife to trim off the lip, but that

  will sit atop the finish floor when it’s installed. If

  would be more time-consuming

  sleeve. (If the main drain is cast iron, use a snap

  the finish floor is not in yet, place scrap under

  and you’re likely to puncture

  cutter to cut it; if it’s plastic, use a wheeled cutter.)

  the flange so it will be at the correct height. If, on

  the sleeve.

  After cutting out the drain section, use no-hub the other hand, the flange is below the finish

  couplings to attach the new no-hub combo fit-

  floor, you can build up the flange by stacking

  ting. Slide a neoprene sleeve onto each end of the plastic flange extenders until the assembly is level

  cut drain, insert the no-hub combo, and slide a

  with the floor. Caulk each extender with silicone

  sleeve onto each end of the combo. Align the

  as you stack it, and use long closet bolts to rese-

  combo takeoff so it is the correct angle to receive cure the toilet bowl. (Check with local codes first

  the fixture drain you’re adding. Finally, tighten

  because not all allow extenders.)

  the stainless-steel clamps onto the couplings.

  Once you’ve secured the closet bend, add pipe

  sections to the bottom of the bend, back to the

  ConneCTIng BranCh

  takeoff fitting on the main drain that you

  DraIns anD venTs

  installed earlier. Maintain a minimum slope of

  1

  After modifying the framing, assemble branch

  ⁄4 in. per ft., and support drains at least every

  drains and vents. Here, we’ll assume that the new 4 ft. Dry-fit all pieces, and use a grease pencil to

  DWV fittings are plastic.

  make alignment marks on pipes and fittings.

  plumbing

  341

  Drilling and notching studs and Joists

  It’s often necessary to notch or drill

  third of the joist’s depth. notches are not

  those studs are doubled and holes don’t pass

  framing to run supply and waste pipes. If you allowed in the middle third of a joist span.

  through more than two adjacent doubled

  comply with code guidelines, given in

  otherwise, notches are allowed if they don’t

  studs; hole diameters must not exceed 60%

  “maximum sizes for holes and notches” on

  exceed one-sixth of the joist’s depth.

  of the width of nonbearing-wall studs. notch

  p. 341, you’ll avoid weakening the structure.

  width may not exceed 25% of the width of a

  although that table is based on the following studs

  bearing-wall stud or 40% of the width of a

  rules of thumb, remember that local building

  Drilled holes must be at least 5⁄8 in. from the

  nonbearing-wall stud.

  codes have the final say.

  stud’s edge. Ideally, holes should be centered

  in the stud. If it’s necessary to drill two holes edge protection

 
; Joists

  in close proximity, align the holes vertically,

  any pipe or electrical cable less than 11⁄4 in.

  you may drill holes at any point in the span

  rather than drilling them side by side.

  from a stud edge must be protected by steel

  of a joist, provided the holes are at least 2 in.

  Individual hole diameters must not exceed

  nail plates or shoes at least 1⁄16 in. thick to

  from the joist’s edge and don’t exceed one-

  40% of the width of a bearing-wall stud, if

  prevent puncture by drywall nails or screws.

  pipe slope

  Dwv pipes slope, so before drilling or notch-

  ing framing, snap sloping chalklines across

  JOISTS

  the stud edges, then angle your drill bits

  zzzzzz notching and Drilling limits

  slightly to match that slope. Drill holes 1⁄4 in.

  Holes OK anywhere,

  Notches 1/6 joist depth,

  larger than the outside dimension of the

  2 in. from edge, minimum

  maximum

  pipe so the pipe feeds through easily. none-

  theless, if Dwv pipe runs are lengthy, you

  may need to cut pipe into 30-in. sections

  (slightly shorter than the distance between

  two 16-in. on-center studs) and join pipe

  sections with couplings. That is, it may be

  No notches,

  impossible to feed a single uncut Dwv pipe

  middle third

  Holes 1/3 joist depth,

  through holes cut in a stud wall.

  maximum

  STUDS

  40% of stud

  60% of

  width, maximum

  stud width,

  maximum

  When hole diameters exceed maximums

  allowed by code, reinforce framing with

  Multiple holes?

  a steel stud shoe.

  Stack ‘em!

  Notches

  25% of stud width,

  Notches

  maximum

  40% of stud width,

  maximum

  Bearing walls

  Nonbearing walls

  342 Chapter 12

  The toilet flange (orange ring) will sit atop the finish

  Support vent stacks in midstory by using plumber’s strap

  floor. If the finish floor has not been installed, place scrap

  to tie stacks to blocking between studs.

  under the flange, elevating it to the correct height. This

  assembly is essentially the same as that shown in

  “Constricted Spaces” on p. 336.

  Other fixture drains. Run the 11⁄4-in., 11⁄2-in.,

  at least 42 in. above the floor, or 6 in. above the

  and 2-in. fixture drains up from the main drain

  flood rim of the highest fixture, and those runs

  takeoff. Drains must slope at least 1⁄4 in. per ft.,

  typically slope upward at least 1⁄4 in. per ft.