Installation
Instructions
Domed Ceilings and
Barrel Vaults
Page 1 of 12
USG Drywall Suspension System
These installation instructions are divided into two parts: Part 1 applies to domed ceilings, and Part 2 applies
to vaulted ceilings. Note: For installation instructions for vaulted ceilings with domed ends, follow Part I for
domed ceilings to build the ends first.
To ensure proper installation, read all instructions before you begin. Check the enclosed Bill of Materials to
be sure that all parts and equipment are present and undamaged. Note: Parts will be permanently damaged if
installed incorrectly.
To generate a set of construction specifications on-line, go to www.usg.com > Resources > Online Tools.
Construction specifications (supplied separately) Bill of materials (BOM)
Parts
Custom curved tees
DGHUB Dome hub (if specified on BOM) DGSP180 Main tee splice plates (if specified on BOM)
DGLW Cross tees (if specified on BOM) DGWC24 Wall attachment clips (if specified on BOM)
Supplies
Tools
Hanger wire Self-drilling screws
12-ga. galvanized steel wire in
straight lengths
In addition to standard 16 to 32 spring clamps Locking “C” clamp
grid installation tools,
you should have:
#2 Philips round washerhead or similar
Technical Service 800 USG.4YOU
Samples, Literature 888 874.2450
Customer Service 800 950.3839
usg.com
Part 1:
curved
primary
spoke
dome hub
hanger wires
electrical box
knockout
center hole for plumb bob
tape measure slots
main-tee splice plate
12-ga. hanger wire
hanger wire holes
cross-tee slot
hanger wire spacing
varies with slope of curve
hub
B
W1
W2
W3
W4
W5
E
Installation
Instructions
Page 2 of 12
Domes
Step 1 Gather construction Dome construction specifications are prepared specifically for each dome, and may be provided by the architect,
specifications
your USG representative, or you can generate a set on-line at www.usg.com > Resources > Online Tools.
These specifications include important tables, diagrams, and dimensions that you will need to install a dome
successfully. For additional help, contact your USG representative.
Step 2 Install the To install the dome hub, identify the correct location and elevation for the center or apex of the dome. Hang
dome hub
the dome hub.
Tip: Form a “pail handle” between two opposite hanger holes so that the hub can be hung from a single wire
(Figure 1).
Tip: Hub detail provides connection points compatible with USG Curvatura™ splice plates, access point for plumb
bob, tape measure slots to aid in arc measurements, and a knockout for a standard electrical box, if needed.
Figure 1- Dome hub
Step 3 Position and install Curved grid is supplied with sets of punched holes spaced 8 apart (Figure 2) along the tee. The two round
Figure 2 – Pre-punched grid Figure 3 – Hanger wire spacing
hanger wires
holes are intended for hangers. Each hanger wire needs to fall in line with a pre-punched hanger hole; because
the spokes are curved, the horizontal distance between hanger wires will vary (Figure 3). See Table 1.1 of the
Construction Specifications for exact hanger locations (dimension B).
Technical Service 800 USG.4YOU
Samples, Literature 888 874.2450
Customer Service 800 950.3839
usg.com
Part 1:
strips of tape
applied to floor
B
45˚
221/2˚
hanger wire
locations for
primary spokes
secondary spokes must
be inserted between
primary spokes where
this dimension exceeds 48"
hanger wire
locations for
secondary
spokes
Installation
Domes
Instructions
Page 3 of 12
Tip: It may be easier to mark hanger locations on a tape measure or a long stick and use this as a template
against the ceiling. If there are many obstructions, it may be easier to mark the locations on strips of tape along
the floor (Figure 4), then use a laser to project the points to the ceiling.
Tip: Extra hanger holes are provided to help work around obstructions; however, the space between any two
hanger wires must not exceed 32
(every fourth hole).
Eight rows of hanger wires radiate from the center of the dome. As these rows diverge by more than 4
additional rows of hanger wires need to be inserted between them (Figure 4).
Figure 4 – Hanger wire locations from floor
,
Technical Service 800 USG.4YOU
Samples, Literature 888 874.2450
Customer Service 800 950.3839
usg.com
Part 1:
dome hub
main-tee splice plate
primary spoke S1
dome diameter "L
"
hub
distance between ends = L x 0.383
s
p
o
k
e
a
r
c
l
e
n
g
t
h
"
D
"
Installation
Instructions
Page 4 of 12
Domes
Step 4 Assemble and hang The first row in Table 1.2 of the Construction Specifications indicates the arc length required for each of the
primary spokes
primary spokes (dimension D). Prepare each spoke by measuring along the arc of the tee and trimming
the end to the required length. Depending on the size of the dome, several tees may need to be connected
to form the length required.
Tip: The vertical slots between the hanger holes are not used in dome applications but will be useful later to
gauge the correct position of headers and cross tees. The slots are exactly 8 apart along the arc of the tee.
Hang the primary spokes from the hanger wires by connecting curved tees to the hub and to each other
(Figure 5) using splice plates provided. Grid face elevations (measured from perimeter) are shown in Table 1.1
of the Construction Specifications to aid in the leveling of spokes (Figure 3) (dimension E).
Figure 5 – Connect curved tees to hub and other tees
Figure 6 – Connect curved tees to hub and other tees
Important
1. Check the elevation difference between the hub and the end of each primary spoke to make sure it agrees
completed installation. Check the integrity of the completed spokes. Extra care at this point will prevent
troublesome alignment problems later.
with the construction specifications. If elevations need to be adjusted, adjust them now.
! The integrity and accuracy of the primary spokes will ultimately determine the quality of the
2. It is important that the main spokes are hung in the proper position relative to each other. Check for proper
position by measuring the distance between the ends of the spokes. These distances should all be the same.
The correct distance between the ends can be calculated by multiplying the dome diameter (ceiling
opening size “L”) by 0.383
(Figure 6). If hanger wires need to be relocated, move them now.
3. Examine each completed spoke from one end. Hanger wires should be in line. They should hang straight
and plumb within 1:6 (about 10 degrees). The spokes should be straight with no waves. If hangers need to
be relocated, move them now.
Technical Service 800 USG.4YOU
Samples, Literature 888 874.2450
Customer Service 800 950.3839
usg.com
Part 1:
A
B
C
grid face
grid face
3
/8"
arc length
"C"
1
/
4
"
Installation
Instructions
Page 5 of 12
Domes
Step 5 Add headers to Steps 5-7 are not needed for domes smaller than 10-1/2 in diameter (dimension L). If your dome is smaller
expand spokes
than this, headers are not required. Go to Step 8.
For domes 10-1/2
in diameter or larger (dimensions L – see page 4), where spokes get too far apart to support
the dome (48 or more), short pieces of tees, called “headers”, are required to span between the spokes. Table 1.3
of the Construction Specifications indicates the length (dimension C) of the headers required. Depending on the
size of the dome, several rows of headers may be required.
1. Prepare eight (8) headers. When cutting headers, they must be trimmed at both ends to avoid interference.
Cut the headers to the length specified in the Construction Specifications (Figure 7A) (dimension C). Snip the
bulb back about 1/4 (Figure 7B) and the face back about 3/8 (Figure 7C). It is important that the headers are
all cut to the same length.
Figure 7 – Trim headers at both ends
Technical Service 800 USG.4YOU
Samples, Literature 888 874.2450
Customer Service 800 950.3839
usg.com
Part 1:
header H1
A
Installation
Domes
Instructions
Page 6 of 12
Step 5 2. Table 1.3 of the Construction Specifications indicates the correct position of each header (dimension A).
(continued)
Position and attach all headers and temporarily hold them in place with spring clamps (Figure 8). Use the
cross-tee holes on the primary spoke as a guide for positioning. The web of the header should fall in line
with a cross-tee hole on the spoke (1/16). The spring clamps will allow you to adjust the positions.
Figure 8 – Hold headers in place with spring clamps
Tip: If the headers seem tight and you’re having difficulty lining up the slots on the spokes, double-check
the lengths of the headers to make sure they’re trimmed properly. All eight (8) headers must be cut to the
same length.
3. Once all headers are in position, clamp the intersection and permanently attach the headers to the spokes
using self-drilling screws (Figure 9). For best results, use #8 x 1/2 washer-head self-drilling screws.
4. Examine each of the spokes from one end to make sure they are not twisted or pushed out of line at the
header intersections. If header adjustments are needed, make them now.
Figure 9 – Screw-attach headers
Technical Service 800 USG.4YOU
Samples, Literature 888 874.2450
Customer Service 800 950.3839
usg.com
Part 1:
secondary
spoke S2
primary spoke S1
distance to
first cross tee slot
distance to first
cross tee slot
header
X
X
secondary
spoke
header
hanger wire
Installation
Instructions
Page 7 of 12
Domes
Step 6 Install secondary Use the primary spokes as a model for hanger locations on the eight (8) secondary spokes. Table 1.2 of the
spokes
Construction Specifications indicates the length of the secondary spokes (dimension D). It is important to have
the slots and hanger holes on the primary spokes line up with the ones on the secondary spokes. The only
way to do this is to build the secondary spokes working inward from the perimeter of the dome. Examine
the end of the primary spoke. Measure the distance from the end of the spoke to the first hole (Figure 10)
(dimension X). Cut the new spoke using the same offset distance and build the new spoke working inward from
the perimeter toward the header (Figure 10). Attach the secondary spoke and a hanger wire to the midpoint
of the header (Figure 11).
Figure 10 – Trim and position secondary spoke
Figure 11 – Attach secondary spoke and hanger wire to midpoint of header
Technical Service 800 USG.4YOU
Samples, Literature 888 874.2450
Customer Service 800 950.3839
usg.com
Part 1:
cross tees
perimeter cross tees
cut to fit 16" o.c.
S2
S3
H2
H1
S1
Installation
Instructions
Page 8 of 12
Domes
Step 7 Install additional Additional headers and secondary spokes are generally needed for domes larger than 21 in diameter
For construction of additional headers and spokes, refer to tables 1.2 and 1.3 of the Construction
Specifications. Progression of assembly is H1, S2, H2, S3, and so on
Figure 12 – Assembly progression of headers and spokes
Step 8
headers and spokes
Install cross tees Beginning at the perimeter, cut, fit, and screw-attach cross tees into all openings so that the maximum
(dimension L).
(Figure 12).
open space is 16 inches (Figure 13). For the length of the perimeter cross tee, refer to the general data in
the construction specifications.
Figure 13 – Cross-tee installation
Tip: Exact locations of cross tees are not critical in this step since their purpose is only to provide a surface for
Step 9
Finish the dome Brace the completed dome suspension system against the surrounding structure as necessary to prevent move-
material attachment.
ment. Apply lath and plaster to the exposed surface of the suspension system as indicated on the architectural
plans. Use StruCto-BaSe™ plaster only. Check the architectural plans for any perimeter transition treatments
that may be required. Examples may be found in the USG drywall suspension system brochure (AC3152).
Technical Service 800 USG.4YOU
Samples, Literature 888 874.2450
Customer Service 800 950.3839
usg.com
Part 2:
12-ga. hanger wire
hanger wire holes
cross-tee slot
hanger wire spacing varies
with slope of curve
apex
F
W7
W5
W3
W1
W2
W4
W6
H
Installation
Instructions
Page 9 of 12
Barrel Vaults
Step 1 Gather construction Vault construction specifications are prepared specifically for each vault and may be provided by the architect,
specifications
your USG representative, or you can generate a set on line at www.usg.com > Resources > Online Tools. The
construction specifications include important tables, diagrams and dimensions that you will need to complete
the vault successfully. For additional help, contact your USG representative.
Step 2 Install hanger wires Curved main tees are supplied with sets of punched holes (Figure 14) spaced 8 apart along the tee. The round
holes are for hangers. Each hanger wire needs to fall in line with a pre-punched hanger hole; because the
spokes are curved, the horizontal distance between hanger wires will vary along the rib (Figure 15). See Table
2.1 of the Construction Specifications for hanger locations. The distances shown (dimension F) are the distance
along the floor and are measured from the apex of the vault. Hanger wires should be installed symmetrically on
either side of the apex.
Figure 14 – Pre-punched grid Figure 15 – Hanger wire spacing
Tip: It may be easiest to mark hanger locations on the floor and then use a laser to project these points
to the ceiling.
Tip: Extra hanger holes are provided to help work around obstructions; however, the space between any two
hanger wires must not exceed the specified maximum indicated on the construction specifications.
Refer to the construction specifications to determine spacing of main-tee ribs. Using Table 2.1 of the Construction
Specifications as a guide, install additional rows of hangers for each main-tee rib.
Technical Service 800 USG.4YOU
Samples, Literature 888 874.2450
Customer Service 800 950.3839
usg.com
apex
apex
H
G
cross tees
cross-tee
spacing as
specified
Part 2:
Installation
Barrel Vaults
Instructions
Page 10 of 12
Step 3 Install main tee ribs The construction specifications indicate the total arc length required for each main-tee rib (dimension G).
Begin constructing each rib by hanging a main tee at the apex. Hang the main tee so that a cross-tee slot
is at the apex (Figure 16). Work outward at both ends, connecting curved tees as needed using splice plates
provided (Figure 17). Grid face elevations (measured from perimeter) are shown in Table 2.1 of the Construction
Specifications to aid leveling of ribs (dimension H). If the barrel vault terminates into a wall, the perimeter
hanger wire may be omitted. Instead, tie back or mechanically fasten the main-tee perimeter as required.
Figure 16 – Hang main tees
Figure 17 – Join curved tees
Step 4 Install cross tees Install cross tees to connect main-tee ribs (Figure 18). Use spacing as indicated on the Construction
Specifications.
Figure 18 – Cross-tee installation
Technical Service 800 USG.4YOU
Samples, Literature 888 874.2450
Customer Service 800 950.3839
usg.com
Part 2:
A
1) insert tab through tee slot
B
2) fold against tee web
3) screw-attach to wall
Installation
Instructions
Page 11 of 12
Barrel Vaults
Step 5 Cut and terminate For perimeter cuts, cut in and terminate cross tees at both ends of the vault.
2. If the barrel vault terminates at a half dome, cut cross tees to fit and mechanically fasten the cut ends to the
Figure 19 – Insert clip
cross tees for
perimeter cuts
1. If the vault terminates at a perpendicular wall, attach a complete main-tee rib against the wall using wall
attachment clips (Figure 19). Space the clips about 4 on center (every sixth slot). Use the ledge of this rib to
attach cross tees. Cut cross tees to fit and permanently attach them using self-drilling screws.
face of the dome spokes.
Step 6 Finish the vault Apply SheetroCk® brand gypsum panels to the exposed surface of the suspension system as indicated on the
architectural plans. Check the architectural plans for any additional perimeter transition treatments that may be
required. Examples may be found in the USG drywall suspension system brochure (AC3152).
Technical Service 800 USG.4YOU
Samples, Literature 888 874.2450
Customer Service 800 950.3839
usg.com
Technical Service 800 USG.4YOU
Samples, Literature 888 874.2450
Customer Service 800 950.3839
usg.com
Literature number AC3157
Manufactured by
USG Interiors, Inc.
550 West Adams Street
Chicago, IL 60661
Product Information
See usg.com for the most
up-to-date product information.
Note
All products described here
may not be available in all
geographic markets and are
subject to change without
notice. Consult your local
sales office or representative
for information.
The following are trademarks of
USG Interiors, Inc. or a related
company: Curvatura, SheetroCk,
truCto-BaSe, USG.
S
Notice
We shall not be liable for
incidental or consequential
damages, directly or indirectly
sustained, nor for any loss
caused by application of these
goods not in accordance with
current printed instruction or
for other than intended use.
Our liability is expressly limited
to replacement of defective
goods. Any claim shall be
deemed waived unless made
in writing to us within thirty
(30) days from date it was or
reasonably should have been
discovered.
Safety First!
Follow good safety and industrial hygiene practices during
handling and installing of all
products and systems. Take
necessary precautions and
wear appropriate personal protective equipment as needed.
Read material safety data
sheets and related literature on
products before specification
and/or installation.
AC3157/rev. 6-06
© 2006, USG Interiors, Inc.
Printed in U.S.A.
Loading...