Instructions / Assembly
13
EXISTING ROOF
APPLICATION
In many cases, FABRAL’s HORIZON S Panels can be installed over existing roong.
Some jurisdictions will allow retrot over certain types of roong without tear-off of the old roong. For
best results, always use furring strips and 30 lb. felt paper over old shingles. Furring strips can be installed
12” o.c. with HORIZON S to provide adequate panel support and wall capability. Check with your local
codes or building department for the specic requirements in your area.
If the roof is to be stripped down to the existing decking, follow the procedures for new roofs on page 13.
Be sure to check the existing roof and repair any damaged areas prior to installation of the new roof system.
The following steps should be taken when installing HORIZON S roof panels over existing roong.
• Inspect the roof for damage and make the necessary repairs.
• Secure any warped or loose roong material.
• Make sure there are no nails or other objects protruding from the roof that might puncture the new un-
derlayment or damage the new roof panels.
• Remove all moss and other debris from the roof.
• Cut off any overhanging roong ush with the roof deck, and remove all hip and ridge caps.
• Follow the directions on page 13, #2 through #4, on roof preparation.
Note: For best results, HORIZON S Roong requires a relatively smooth and at substrate. Application
over rough and/or uneven surfaces is not recommended, as this will cause oil-canning.
PANEL INSTALLATION
Note: Prior to panel installation, determine which items need to be installed prior to panels (such as vent
screen, eave, valley, swept wing, etc.)
1. Install eave trim.
2. Working off the eave edge, establish a straight line up the gable edge from which you are starting. This
will insure that the rst panel laid will be straight and square with the eave. (See Illustration #2 – page
13)
3. Before fastening the panel to the roof deck, hem 1” of the panel 180 deg. (or allow a 1” overhang to
attach an angle piece to the eave when using WEF4 alternate eave detail).
4. Once the rst panel is in proper position, secure it to the roof deck with the proper fasteners along the
screw ange (#10 x 1” Waferhead panel screw on 12” centers maximum.)
5. Install the gable trim and face screw it to fascia board (see page 21). This fully secures the rst panel to
the roof.
6. Position the second panel (overlap edge on top of the underlap edge of rst panel) assuring that the
eave edge is in position (1” overhang). Secure the second panel to the rst panel by applying slight
pressure on the overlap seam (or use rubber mallet) working from the eave toward the ridge. The over-
lap edge of the panel contains factory-applied sealant to ensure weathertightness. Be sure that you
achieve a positive engagement between panels. Fasten the panel to the roof as in step #3 above.
7. Each consecutive panel will be applied as in step #3 and #5 above.