Renovation 4th Edition

by Michael Litchfield

  side casings 1⁄2 in. long, the head casing will be

  spreading, so remove the tacked-up casing, and

  that much higher than the head reveal line. But

  splice the joints with biscuits, as described earlier

  with all casing elements in place, you can see if

  in this chapter. Spread glue on all joint surfaces,

  the head casing butts squarely to the side casings, and nail up the side casing. (Insert biscuits, if

  or if they need to be angle trimmed slightly to

  used.) Draw the head casing tight to the side cas-

  make a tight fit. Use a utility knife to mark where ing by angle-nailing a single 4d finish nail at each

  the head reveal line hits each side casing, and

  end. To avoid splits, predrill the two nail holes or

  remove the side casings and recut them through

  snip the nails’ points. Then remove excess glue

  those knife marks. Retack the side casings to the

  with a damp cloth.

  Finish Carpentry

  491

  INSTALLING SqUAre-CUT DOOr CASING

  Square-cut head casing can easily span ganged windows or, as shown, a double door with windows on both sides. Here,

  a carpenter tacked up the door side casings before eyeballing the head casing to be sure the joints were flush.

  Use a pin-tacker (brad nailer) to tack the head casing until Slightly back-cut the side casings to ensure a tight fit to you’re sure all joints are tight. When that’s done, secure

  the underside of the head casing.

  the casing with 6d finish nails.

  492 Chapter 17

  installing Mitered door Casing

  confident you can cut the correct angle on the

  first try.) Miter-cut the top of the side casing so it

  Before installing the casing, first use a framing

  matches the bisecting angle you worked out ear-

  square to see if the doorway corners are square.

  lier on the scrap. Square-cut the bottom of the

  If they aren’t, use an adjustable bevel to record

  casing, and tack it to the frame using 18-ga. or

  the angles and a protractor to help bisect them.

  20-ga. brads.

  Then cut the miter joints out of scrap casing until Cut one end of the head casing in the same

  their angles exactly match the frame. You can

  bisecting angle, leaving the other end long for the

  install mitered casing by first cutting the side cas- time being. Fit the mitered casing ends together,

  ing and then the head casing, as you would with

  and align the bottom edge of the head casing to

  square-cut casing. But some carpenters maintain the head reveal line. Then, using a utility knife,

  that the best way to match mitered profiles is to

  mark the head casing where side and head

  work around the opening. That is, start with one

  reveals intersect in the second corner. You’ll cut

  side casing, cut the head casing ends exactly, and through that mark, using the bisecting angle for

  finish with the second side casing.

  the second corner (which may be different from

  Mark the first piece of the side casing, and

  the first corners). Again, there’s no shame in

  then cut it. After marking a 1⁄4-in. reveal around

  recutting, so you may want that utility-knife

  the frame, align a piece of casing stock to a

  mark to be 1⁄4 in. proud. When its miter is correct,

  reveal line on a side frame. Where head and jamb tack up the head casing, then line up the inside

  reveals intersect in the corner, make a mark on

  edge of the second side casing to the side reveal

  the casing, using a utility knife. (Or make the

  line. Use a utility knife to locate its cutline.

  utility-knife mark 1⁄4 in. higher if you’re not

  Back-cutting miters slightly can make fitting

  them easier.

  Whether you simply glue mitered joints or

  biscuit-join them, remove all three pieces of cas-

  ing before securely nailing them. If biscuit join-

  SIMPLE BUTT JOINT

  zzzzzz Baseboard and side Casings

  ing, after slotting each piece, reinstall the leg

  Ideal y, door

  jambs, apply glue and biscuits, and fit the head

  casing will

  be thicker

  than the

  baseboard.

  PLINTH-BLOCK JOINT

  Plinth block is thicker

  than door casing

  or baseboard.

  If baseboards are the same thickness as

  door casings, simply butt them together,

  or shape the end of the baseboard slightly

  to reduce its thickness.

  recutting miters is a normal part of installing casing. To adjust for a slight gap

  at the bottom of the joint, this carpenter is marking the amount he needs to

  remove from the top of the side casing.

  Finish Carpentry

  493

  casing down onto the biscuits. You can use miter

  clamps or 18-ga. brads to draw the joint together

  Corner-Block Casing

  until the glue dries. Be sure to wipe up the excess

  glue immediately.

  Casings with corner blocks are a variation of square-cut casing in which you have

  seven pieces of trim—two plinth (base) blocks, two cap blocks, two pieces of side

  casing, and one head casing—to measure, cut, and fit.

  Casing a Window

  start by installing the plinth blocks, which are thicker and wider than the side

  Casing windows is essentially the same as casing

  and head casing. plinths and cap blocks may line up to reveal lines on door frames,

  doors, so review earlier sections about prepping

  or they may line up with the inside frame edges; be sure to match the detailing of

  frames and installing casing. The main difference

  the existing casing.

  is that the side casing of windows stands on a

  tack up plinths, using 18-ga. brads. then measure from the reveal line on the

  window stool, rather than on the floor. Conse-

  head frame to the top of the plinth blocks to determine the length of side casings.

  quently, most of this section describes measuring

  tack up the side casings, aligning them to the reveal lines on the side frames.

  and cutting the stool, which covers the inside of

  a windowsill, and the apron beneath the stool.

  depending on the detailing of the cap blocks, you may need to recut the tops of side

  Sills and stools vary, as described in “Window-

  casings. recut the side casing as needed, then tack up the cap blocks and place a

  sills, Stools, and Aprons” on p. 496. The following

  spirit level atop them to see if their top edges align and if they’re level.

  text focuses on installing replacement stools

  Finally, measure between the cap blocks to determine the length of the head cas-

  appropriate to older windows.

  ing. (use a rigid folding rule with a slide-out extension for this task.) if the door

  frame is slightly out of square, cut the head casing 1⁄16 in. to 1⁄8 in. long, and back-

  cut both ends so you can shave them to fit. once the tack-fit is tight, carefully pry

  off the tacked-up pieces, cut biscuit slots, glue, insert biscuits, reassemble the pieces,

  and finish-nail the assembly. glue all joints even if you don’t use biscuits.

  Rough jamb

  zzzzzz
Window trim

  (trimmer stud)

  Frame jamb

  Bottom

  Side

  sash rail

  casing

  Stool

  Pitched

  horn

  sill

  Stool

  Apron

  Rabbeted underside

  of stool

  Interior wall

  Exterior sheathing

  Nail window casing to frame jambs and to the rough

  Use 6d or 8d finish nails to attach casing to rough jambs,

  opening, spacing finish nails every 16 in. Use a

  4d finish nails to attach the inside edge of casing to frame

  combination square to line up each pair of nails.

  jambs, and 4d nails to tie the stool to the apron edge.

  494 Chapter 17

  MarKing the WindoW stool

  Before you start, decide how far the stool “horns”

  will extend beyond the side casings and how far

  zzzzzz Cutting a Window stool

  TOP VIEW

  the interior edge of the stool will protrude into

  Interior dim. of window frame

  the room. Typically, horns extend 3⁄4 in. beyond

  31⁄2-in.-wide side casings, but use the existing cas-

  1. After transferring the

  ings as your guide.

  1

  interior dimensions of the

  To determine the overall length of the stool,

  window frame to the stool

  SIDE VIEW

  mark 1⁄4-in. reveals along both sides of the frame

  stock, cut across the stock til

  jambs. Then measure out from those reveals the

  the saw blade reaches the

  width of side casings plus the amount that the

  stool shoulder.

  stool horns will extend beyond that casing. Make

  Shoulder line

  Waste

  light pencil marks on the drywall or plaster. Rough-

  cut a piece of stool stock slightly longer than the

  2. Fol owing the shoulder line,

  distance between the outermost pencil marks.

  2

  cut in from the ends of the

  Next, hold the stool stock against the inside

  stock to create horns.

  edge of the windowsill, centered left to right in

  Horn

  the window opening. Using a combination

  square, transfer the width of the window frame,

  from the inside of one jamb to the other, to the

  Waste

  stool stock. Use a jigsaw to cut along both

  squared lines, stopping when the sawblade

  3. Rip down the stock so its

  reaches the square shoulder in the underside of

  3

  beveled portion butts the inner

  the stool. So you’ll know when you’ve reached

  window sash, less 1/16 in.

  that shoulder, lightly pencil the width of the

  Final bevel

  shoulder onto the top of the stool, using a combi-

  width

  nation square as a marking gauge. Next, cut in

  from each end of the stock to create the horns.

  Carefully guide your saw along the shoulder

  lines, being careful to stay on the waste side of

  Waste

  the line. Clean up cutlines with a chisel, if needed.

  4. Trim the horns of the stool

  The cutout section of the stool should now fit

  4

  so they protrude 3/4 in. beyond

  tightly between the jambs. Now, rip down the

  side casings.

  rabbeted edge of the stool so that it will be snug

  against the window sash, and the stool horns will

  be flush to the wall (and jamb edges). Push the

  arched Window Casing

  stool in until it touches the bottom of the sash,

  then pull the stool back 1⁄16 in. from the sash to

  there’s something inspiring about arched windows. restoration carpenter jim

  allow for the thickness of paint to come. Finally,

  spaulding (shown on pp. 498–499) offers this advice: “order all the casing from the

  measure the distance between the stool horns

  same shop so that the same knives cut the arches and the legs (side casing). that

  and the wall, which is the amount to reduce the

  width of the stool, along the rabbeted edge.

  way, all the profiles will sweep continuously around the frame.” arched casings are

  Use a tablesaw to rip down the width of the

  different from casings for other windows, so installing them takes some flexibility.

  stool, then test-fit it again. If it is parallel to (but

  after setting the stool and apron, for example, you install its head casing next. side

  1⁄

  casings are last.

  16 in. back from) the sash rail, you are ready to

  cut each horn to its final length. If your stool is

  although modern window makers offer a limited selection of prefab casing for

  flat stock, that’s the last step. But if the stool is

  the arched windows they sell, plan on custom-ordering casing for older arched win-

  molded (has a shaped profile), miter returns to

  dows. Correctly determining the radius of the arch is challenging: one method is to

  hide the end grain of the horns, as shown in the

  tack 1⁄8-in.-thick plywood (also called doorskin) to the inside edge of the arched

  top photo on p. 487.

  frame head—run it about 1 ft. below the “spring line” of the arch, where the frame

  becomes straight. go outside and trace the arch, tracing lightly so you don’t bow the

  attaChing the stool and apron

  plywood. Make templates for each arched window, and take them to a local shop

  Lightly sand and prime the stool, including its

  that mills trim.

  underside and ends, so it won’t absorb any mois-

  Note: the inside edge of arched casing must be revealed (set back) from the arch

  ture from condensation or driving rains. After the

  you traced of the frame’s inside edge.

  paint is thoroughly dry, apply waterproof glue to

  the underside of the stool, level it, and nail it to

  Finish Carpentry

  495

  the rough sill using two or three 6d galvanized

  INSTALLING A WINDOW STOOL AND APrON

  finish nails. Try not to lean on the only partially

  supported stool until it’s nailed to the top of the

  apron, which will steady the stool.

  Next, cut the apron, which is generally the

  same casing used for side and head casing. Its

  thicker edge is butted to the underside of the

  stool. The apron should be as long as the head

  casing so that it lines up visually with the outside

  edges of the side casing. If the apron is molded,

  cope each end to accentuate its profile or miter-

  cut it and glue on a return. If you’ll be painting

  the casing, caulk along the underside of the stool

  to prevent drafts. Then butt the apron to the

  underside of the stool. Nail up the apron, driving

  6d finish nails into framing beneath the sill.

  Start casing a window by installing

  Typically, the apron is as wide as the casing above the

  Finally, nail the stool to the top of the apron,

  its stool. Use a combination-square

  window stool; the stool horns project 3⁄4 in. beyond both.

  using three or four 6d galvanized finish nails.
>
  level or a torpedo level to level it,

  Set and fill those nails.

  then 8d finish nails to secure it to the

  rough sill underneath. However, the

  install the side and head casing in the same

  stool won’t be stable until it is also

  order that you would case a door: side casing,

  nailed and glued to an apron under

  head casing, and second side casing. The main

  its inside edge.

  difference is that window side casing sits on the

  stool horns. If you’re casing side-by-side windows

  with flat trim, you can run a single piece of head

  casing over both windows and butt the middle

  Windowsil s, STOOLS, And ApROnS and side casings to the underside of the head cas-

  ing, as shown in the top photo on p. 492.

  Windowsills have both an inner and outer life—one half is interior, and the other is

  exterior. it makes sense to pitch the outer portion of a sill so it can shed water. but in

  the old days, windowsills were pitched all the way, front to back, which created a use-

  Baseboard and

  lessly pitched interior section that had to be covered with a stool piece, as shown in

  Crown Molding

  “Window trim” on p. 494. to fit a pitched sill, usually set at 14º to 20º, the underside

  As noted in “The Case for Not Leveling Trim” on

  of a stool must be partially rabbeted at the same angle so that when the stool is

  p. 488, baseboard and crown molding should fol-

  nailed on top of the sill, the top face of the stool will be level. it’s an archaic design,

  low floors and ceilings, rather than level lines

  but, surprisingly, it survives in some new window designs.

  projected across the walls. If floors and ceilings

  Many modern windows, however, have a sill whose interior portion is flat on top and

  are level, fine. Otherwise, leveled trim next to

  flush to the insides of the window frame. consequently, there’s no need for a stool or

  out-of-level surfaces is glaringly obvious.

  an apron. such windows may be “picture framed.” that is, the casing can be mitered

  around all four sides of the window frame.

  installing BaseBoards

  if your windows have traditional stools and aprons, the trickiest part of casing the

  Install the finish floors first, with a slight gap,

  windows will be fitting the stools. typically, a stool’s outer edge almost abuts the

  typically 1⁄2 in., between the wood flooring and

  inside of the lower window sash (allow a 1⁄16-in. space for the thickness of paint), and