Window Heads
Window headers are available in many different heights and can be sized to a necessary width. If the width adjustment is necessary, determine the correct width and mark from both ends of the breast board half the distance. To cover the seam, a keystone can be used. Window headers can be routed for j-channel when necessary although, when siding will be present a shim board is the recommended alternative.
Shim Board Applications
If vinyl siding will be present, it is recommended that a ¾” shim board be used instead of having a window head routed for j-channel. Before the siding is installed, mount either a ¾” Nu-Wood board or a wood board directly to the subsiding. This board does not have to be the exact size of the header. It is best to be at least ¾” less in height. After properly flashing, the shim board siding may be installed and then the window header placed over the top. This technique also completes the appearance of the window header since it is brought out in front of the siding rather than flush with the j-channel.
Arches
Arches are available in most half round windows sizes. To measure for an arch trim, determine the width at the base of the unit. (This is the diameter of the half round) When siding is present, a flexible j-channel may be used around the arch. If the trim will be extended vertically down the side of another window, an end cap may be ordered. This creates a more finished seam where the two trim pieces connect. If the end cap will not be used, be sure to use Nu-Wood adhesive at the joint. Follow the general guidelines for other applications.
Customer arches and ellipses are available.
SUNBURSTS
With most applications, follow the general guidelines when installing sunbursts. Sunbursts can be routed for j-channel if necessary or they can be mounted over a shim board. If a shim board is used, it must be large enough to properly secure the sunburst to avoid wind damage. If mounted directly to the subsiding and if siding will be present, flexible j-channel should be used.
Gable Vents
Gable vents may be ordered either as a functional or non-functional vent. Most can be routed for j-channel. In the case of the functional vent, the opening to the attic does not need to match the shape of the vent and should be smaller in size. It is often easiest to cut an undersized square or rectangular opening in the sheathing. Fasten the vent over the opening with both Nu-Wood Adhesive and screws/nails.
Non-functional or closed vents can be installed using the general guidelines. In some cases it may be best to use a shim board. Undersize the board as a square or rectangle and install the siding. At this point the vent can be mounted over the shim board.
Mouldings
Typically, moldings should be installed directly to the sheathing or brick. Long lengths of molding will expand and contract leading to shrinkage over time. Always use a combination of Nu-Wood Adhesive and screws to help avoid some of this movement. When pieces will be joined together, be sure to square or miter ends and use Nu-Wood Adhesive at the joint. It is very important to fit each piece tightly against the other. This may be accomplished first by over sizing the length slightly. After applying the first piece, install the second piece beginning at the far end and forcing it against the first piece until it a slight bow occurs. Fasten the moldings starting at the far end moving toward the first piece. Then, fasten every 16” hitting the studs or a solid surface. Follow the general finishing guidelines when done.