33To make installation easier, put the appliance in place and install the vent system before framing thefireplace. Remember to install the required clearance post on top.If you install your fireplace on an outside wall or in an alcove, use a firewall and drywall in compliancewith local building codes.3.1.4. TOP CLEARANCETop clearance post are not installed whenyou receive your fireplace. They must bemounted before installing the unit. Eightmachine screws are already placed on topof the fireplace where clearance post willgo (2 screws per spacer). Please see thefollowing illustrations.3.1.5. FACING MATERIALSOnly non-combustible materials (brick, slate tile, steel or other non-combustible materials allowed by localstandards) can be used to cover the appliance’s non-removable/fixed surfaces.WARNINGBefore framing your fireplace, check dimensions, framing methods and finished wall facingdetails. Determine the total thickness of the finishing material – drywall, ceramic, tile, slate, etc.Make sure the finished surface will be flush with the front or side of the unit.Figure 3.1.3.a Figure 3.1.3.bCAUTIONNever obstruct the air duct inlet or outlet. This could pose a risk of overheating, which could leadto a fire.CAUTIONRemote wiring (wall switch) must be before the facing materials to avoid costly reconstruction.The appliance must not be completely enclosed in an alcove. Clearance above the top of thefireplace is 0 in. from the top clearance post. This means that combustible building materials canrest directly on top of the upper mounts.You must leave a 3 in. clearance between the first 8 ft. of vent and combustible materials(unless protected by a firewall). The rest of the vent requires a clearance of 1 in.