One of my favorite parts of framing a house is doing the
interior-detail pickup framing — elements like arches,
barrel vaults, and coffered ceilings. In this article, I'll
show a simple method for framing a hipped tray ceiling —
a ceiling that looks like the underside of a hip roof except
that it's flat on top (Figure 1).
Figure 1.A hipped tray ceiling (top) adds visual
interest without a lot of additional framing cost. It's framed
like a hip roof except that it's flat on top
There's nothing unusual about this shape, but we've gotten the
process down to the point where we can lay it out quickly and
hand most of the work off to the less experienced carpenters on
Ceiling as Roof
To help newer framers visualize the ceiling, we use
roof-framing terminology to describe the pieces. The members
running up from the sides of the opening are called "commons"
and the ones in the corners are "hips." These "rafters" butt
against a lower rim board at the inside face of the soffit and
angle up to meet the flat surface at the top of the tray. The
flat area is bound by horizontal rim boards that catch the
upper ends of the rafters and the tray ceiling joists that span
from rim to rim.
The trays we build are small enough that all the framing
members except the soffit rim can be made from 2x4s. The soffit
rim should be at least as tall as the room's ceiling joists; we
often make it from 2x12s.
Sizing rule of thumb. These ceilings typically go in master
bedrooms. In rooms of that size, it generally looks good if the
commons are about 3 feet long. They could be longer or shorter,
but we've found that regardless of the pitch, 3 feet is
dramatic enough without overpowering the room. It's also a nice
round number to work with.
We also have to determine what slope to use for the sides of
the tray. On upper floors, we try to match the pitch of the
roof so that the tray rafters near outside walls won't hit the
roof rafters or come so close it's hard to insulate.
We calculate our cuts and layout based on the 3-foot
common-rafter length. The length of our tray rafters
corresponds to the line length of a roof rafter — the
distance between the head cut at the top and a line projected
up from the plumb cut at the birdsmouth. Because the tray
rafters butt to rim boards top and bottom, they don't need
birdsmouths; instead, they have plumb cuts at both ends.
The photographs in this story come from a house with an 8/12
pitch roof, so that's the pitch we used for the tray ceiling.
We knew the rafters would be 3 feet long, so the only thing we
had to calculate was the length of a hip and the run of a
common. The easiest way to do these calculations is with a
Construction Master (Figure 2). I use a Construction Master Pro
Trig Plus III set to round to the nearest 16th inch.
The Geometry of a Hipped Tray
Figure 2.Laying out a hipped tray ceiling —
like the one in the drawing below — is like laying out a
hip roof. The author usually starts with a known rafter length
of 3 feet and often matches the pitch of the roof above. The
calculations shown here are based on an 8/12 pitch. With this
method, the only other dimensions the framer needs to know are
the length of the hip and the run of the common, information
that's easy to get from a Construction Master using the
After entering the pitch (8) and the length of the common (3
feet), the calculator gives us the length of the hip (3 feet
1013/16 inches) and the run of a common (2 feet 515/16 inches).
We write both numbers down and put the calculator away; that's
it for the math.
Everything else from here on out is a matter of measuring,
marking, cutting, and installing.
Rise doesn't matter. If we were framing a roof, we'd want to
know the rise of the commons to know how high above the plates
to support the ridge while we installed rafters. But with a
tray ceiling, the rise matters only if you're installing it in
a dropped ceiling and need to fit it beneath the joists.
The ceiling shown here bumped into a large attic space, so we
didn't have to worry about its height.
Laying Out Commons
To lay out the commons, we draw a pair of lines 3 feet apart
and square across the edge of a 2x4. We then use the Speed
Square to mark the two parallel lines, 3 feet apart on the
2x4's face, representing the plumb cuts at each end (Figure 3).
We saw through the 2x4 at both lines and use this first common
as a pattern to mark the others.
Figure 3.The rafters for a tray ceiling have plumb
cuts on both ends. To use a Speed Square to lay out the 8/12
plumb cut on the end of a common, set the pivot point against
the edge of the stock and align the number 8 on the "COMMON"
scale with the edge of the stock (top). Use the same method to
lay out the 8/12 plumb cut on the hip, but index off the
"HIP-VAL" scale (bottom).
To save time, we stack the material for the commons, trace the
plumb cuts onto the top piece, and make the cuts with a saw set
deep enough to score the cut on the piece below (Figure
To save time cutting the commons, the
carpenters stack the material and score the cut on the second
piece while cutting the top piece.
Laying Out Hips
We lay out the hips the same way, again with the Speed Square,
but using the hip-valley scale this time.
Bevel cuts. The ends of each hip get beveled with a saw set to
45 degrees so that the top will fit between the king commons
and the bottom will fit the inside corner of the opening. Using
the Speed Square, we mark the hip plumb cut at one end of the
hip, then make a second line parallel to the first and 11/2
inches — the thickness of the stock — away. (If the
stock were 13/4 inches thick, the second line would be 13/4
We use these lines to guide the saw through the two bevel cuts
that will produce the desired 90-degree point (Figure 5). With
the saw set to a 45-degree bevel, we cut through the 2x4 at the
line closest to the end of the board. Then, without flipping
the board, we cut along the inner line (that's 11/2 inches
away), bringing the saw in from the other edge.
Figure 5.Here, a carpenter lays out the first set
of bevel cuts on a hip by drawing parallel lines at the angle
of the plumb cut on the hip. The distance between the lines is
equal to the thickness of the stock — in this case, 11/2
inches (A). It takes two 45-degree bevel cuts to cut the end of
the hip. The first cut is made on the outer line with the blade
angled toward the other end of the stock (B). The second cut is
on the inner line with the blade angled toward the cut end (C).
The result is a 90-degree point (D) in plan view that will fit
the inside corner of the opening or between the king commons
where they meet at the upper rim.
The two cuts cross at the center of the stock and give us the
diamond-shaped point we're looking for.
Getting the length right. We complete the hip by making a
mirror image of this cut at the other end of the stock. The
finished piece should be 3 feet 1013/16 inches point to point,
so we measure this distance down the edge from the diamond cut
we already made.
We make a mark, then use the Speed Square to draw an 8/12 plumb
cut at the mark with the hip-valley scale. This new line
represents the long point of the diamond cut we want to make
Figure 6.To lay out the second set of bevel cuts
on the hip, the author first marks the calculated length of the
hip, measuring from the long point on the other end. A pair of
lines 3/4 inch to either side mark the bevel cuts.
Next we draw a second and third line parallel to the first and
3/4 inch to either side of it. The first line is now centered
between parallel lines that are 11/2 inches apart. Our first
45-degree bevel cut is along the outer line with the blade
angled back in. Our second bevel cut is along the inner line
with the blade angled out. The cuts will cross to form a point
at the center line, 3 feet 1013/16 inches from the cut at the
The tray has four hips, so we cut three more that are exactly
the same as the first. The number of commons will vary with the
size of the opening, but they all must be accurately cut
because the way we install them leaves no room to fudge.
While a more experienced carpenter is calculating and cutting
the hips and commons, I'll have two less-experienced carpenters
frame the soffit around the opening in the ceiling. We
typically bring the soffit in 24 inches from the edge of the
room. We usually know in advance that we're going to install a
tray ceiling, so when we roll the joists we use pieces that run
partway into the opening and stop. (We use bearing ridges on
most of the houses we build, so it doesn't matter that the
joists don't reach from plate to plate.)
If we're framing a 24-inch soffit and using a single rim board,
we snap a line across the joists 221/2 inches in from the wall
and trim the joists back to that line, making sure the cuts are
plumb (Figure 7).
Figure 7.The author's crew frames the opening by
carefully trimming the joists in a straight line (top), then
nailing on a 2x12 rim board (middle). Rafters will be installed
above the line on the rim. On the outside wall, the rim is
positioned plumb against the rafters using short nailing blocks
Lower rim board. Although the joists are usually 2x8s, we use
2x12s for the rim because the added height allows us to install
rafters several inches up from the bottom of the opening. This
leaves a vertical surface below the slope large enough to
install a crown with cove lighting.
If we chose to, we could make the rim the same height as the
joists and install the rafters flush to the ceiling.
We start by cutting rims and nailing them (crown side up) onto
the ends of the joists. We then install a second pair of rim
boards perpendicular to the first, 24 inches out from the walls
at the ends of the opening.
We check to make sure the entire opening is plumb, square, and
straight. If it's not, the precut hips and commons won't fit
properly and it will show in the finished ceiling.
Installing the Tray Ceiling
With the soffit framed and the hips and commons cut, it's time
to install the rafters. But first we have to mark their layout.
We like to install rafters 5 to 7 inches up from the bottom of
the opening, so we snap a line at the right height on all four
The hips land at the inside corners and the commons are spaced
24 inches on-center along the rims. But the commons on either
side of each hip (the king commons) have to be a specific
distance out from the corner, equal to the run of a common
— in this case, 2 feet 515/16 inches. This ensures that
the hip and king commons converge at the same point.
King commons and hips. Unlike roof rafters, which need
immediate support at the ridge, tray ceiling rafters can be
installed by toenailing them to the lower rim. They're so short
and light that toenails will hold them until we get around to
installing the upper rim (Figure 8).
Figure 8.King commons, which flank the hips, are
positioned the same distance out from the corner as the run of
a common — in this project, 2 feet 515/16 inches (top).
The rafters install fast because toenailing holds them in place
until the upper rim is installed. After the hips are nailed up
(middle), the king commons and hips get nailed together at the
Again, this is why we didn't bother to calculate the rise of
the commons: If our cuts are accurate and we nail the hips and
king commons tight to the rim, all the rafters automatically
top out at the same elevation.
We measure out from the corners of the rim and nail the king
commons in place. Next, we toenail the hips in the corners. The
hips and king commons will converge, and we nail them all
together where they meet. (Be careful when positioning these
pieces for nailing: If you hold on at the wrong spot, you could
easily shoot a nail into your hand.)
Upper rims. Once all the hips are nailed to the king commons,
it's time to install the upper rim pieces. There's no need to
calculate their lengths; all we have to do is measure from
corner to corner where the hips and king commons meet. We cut
the pieces from 2x4s and nail them at the corners (Figure
Figure 9.While it's possible to calculate the
lengths of the upper rim pieces, the author finds it quicker
and easier to install the hips and king commons (A), measure
between them (B), and then cut the rim pieces to fit (C). Once
the upper rims are in place (D), it's a simple matter to
install the commons and run ceiling joists across the
At this point, the upper rim goes all the way around the
opening and is supported at the proper height. Next we install
the commons 24 inches on-center between the king commons.
Commons and joists. The only framing left is to install 2x4
ceiling joists between the upper rims. Once more, we install
these pieces 24 inches on-center. If there's going to be a
light or fan in the tray, we avoid running a joist across the
center. There's no need to install hip jacks because the
drywall will be able to span from hip to king common without
any added support.
Cost to Frame
A while back I timed how long it took me to frame a tray
ceiling by myself. It took about two hours, but I was going all
out. If I do the math and make a pattern for the hips and
commons, the less experienced guys on our crew can frame a tray
ceiling in about three man-hours.
Compared with the value that a tray ceiling adds to a new home,
the material cost to frame one is almost negligible. The only
things we have to go out of our way to get are the long 2x12s
used for the lower rim. None of the 2x4s are very long, so we
can usually get them from scrap.
Tim Uhler is a lead framer and exterior
trim carpenter for Pioneer Builders in Port Orchard,