Steel Framing a Gas Direct Vent Horizontal Fireplace
Horizontals are the big trend in gas fireplaces for 2012.
They have one big safety issue and that is the high heat around and in front of the unit. It makes sense. Unlike other fireplaces, the exposed viewing window is only about 1/2 of the fireplace body; the other half is hidden behind the framing and finishing. It takes special care in framing and finishing and I prefer to frame with steel studs and cement board.
READ YOUR MANUAL for framing and finishing details.
A final thought, I would not buy a horizontal that did not take a fan. It disperses the heat.
You need; yellow handle straight tin snips, screw gun, chalk line, good level, #2 Robertson and Philips screw bits, 9/16 waferhead screws (for steel studs), 2″#8 wood screws, self tapping drywall screws, 2×2 steel studs, channel and the FIREPLACE MANUAL(a must read). The studs are screwed into the top and bottom plates (channel) to make the wall.
Before you start, make sure the gas fitter (installer) has tried everything, fan, remote, pressures etc and that it works perfectly. As you frame it in, you block easy access to controls.
I am framing a Regency HZ40E gas fireplace on a raised wooden base, corner installation (premium fireplace). There is no mantel (no load) so I am using the lightest studs, 2 x 2. To accommodate a window on the right side, the wall will stop at the bottom of the window and a smaller wall set back about 8″ continuing to the ceiling. The mantel ledge is like a long triangle (client design) with only the right side going back 8″.
The base was installed the correct dimensions away from the corner (measurements in manual). The fireplace was levelled horizontally and vertically and centred in the space. The fireplace sticks out 2″ past the base to accommodate full 2 x 2 studs (easier to frame a full wall). The metal standoffs on the fireplace were secured in place for only a drywall finish (no tile or stone). For another finish, adjust the measurements for final finish(read the manual). I fasten the top and side cement board pieces (supplied). This is now the finished surface measurement for the wall.
At this point I ignore the base and place a level vertically on the fireplace cement board and mark the floor at each side. Measure back 1/2″ and snap a chalk line to the two walls through those marks. This is the bottom plate of your steel wall. The 1/2″
reduction allows for your final drywall. Here is the beauty of steel studs. You cut everything with essentially scissors. Measure the bottom line wall to wall and cut two pieces of channel that number. Because this is a corner install, cut back on each end 45 degree to allow the piece to fit on the line and screw to the floor. Now I measure to the bottom of the window and cut a couple of studs to that measurement (less 1/4″ for easier fit). Place the two studs into the bottom channel at each side of the fireplace behind the cement board and fasten with drywall screws. Place the other channel on top of the two studs. The top channel should touch the top side walls and be level. Adjust if necessary. Cut and secure the remaining studs. Put them at one foot on centre. I now fasten a 3/4 ” x 10″ plywood piece to the top of the 2 x 2 stud wall, flush to the front. I braced underneath the plywood at the sides. Snap another line on top of this piece for the desired upper wall location and cut another two pieces of channel. Secure bottom channel to line on mantel top and cut studs to ceiling (less 1/4″). put a couple of studs in the bottom channel, screw in place and put on top channel. Level and secure to ceiling.
When you are framing the top and bottom of the wall, you need to add channel pieces horizontally to secure those studs in place. Add enough studs to have them at one foot intervals or wherever there might be a drywall joint.
Fill in the drywall around the cement board and you are done.
I always cut the largest pieces of drywall possible to avoid joints. You can see, around the fireplace, I have used a full 4′ piece cut to width and cut out the area where the fireplace and cement board is. It takes practice to make these cuts. An easy way is to measure the areas to be cut out and mark that down. Partially screw the “cut to width” drywall piece in place and mark your measurements out and cut carefully in place with a knife and drywall saw. Always mark any stud locations on the floor or ceiling and when in place use a level and lightly mark the wall for screw locations.
Put 1 screw for each 16″ and every foot at seams.
Did I mention “READ THE MANUAL”.