Installation Guide

window and door trim
To Install a Keystone
(to shorten or lengthen a mantle)
NOTE: Mantel keystones can be
purely decorative, or can be used to
modify mantels.
Determine the length of mantel
necessary. Using this measurement,
cut two equal pieces of the mantel
(each will be one-half the length of
the required total length). (Fig.1)
Clean the cut ends.
Drill three holes 3/16˝ in diameter
into each mantel piece spacing holes
1-5/8˝ from the centerline (along the
cut ends of the mantels). (Fig. 4)
If placing mantel keystone over
dentil blocks, you may need to cut
away a thin section on both sides of
mantel to accommodate keystone
over dentil blocks.
Place keystone face down on clean
work area. Insert one mantel section
into keystone and align drilled
holes with molded screw bosses
in keystone and fasten with three
screws. Insert and fasten second
mantel section with three screws.
(Fig.2)
To set clip locations when mantel has
modified or cut, measure from new
mantel cut centerline to the locking
legs. Install clips as described.
Install clips to wall. You must
determine the distance to place clips
from the center of modified mantel.
(Fig.3)
To stabilize the mantel system, it is
recommended that a piece of fitted
plywood be screwed into the back
of the mantel system behind the
keystone.
Install mantel as described in
Standard Mantel installation.
Center all Holes 1
5
/
8
"
from Centerline
Centerline
3
/8"
3
23
/32"
23
/32"
2" Ab
ove
Bottom of
Mantel
4
3
/4" Above
Bottom
of Mantel
Fig.1
Fig. 2
Fig. 3
27
TOP FRONT EDGE OF MANTEL
1
5
/ 8 ´´
3
/ 8 ´´
3
23
/ 32 ´´
1
5
/ 8 ´´
23
/ 32 ´´
CENTERLINE
Fig. 4