September 17 - Building the Big, Complicated Firewall

No Ordinary Wall -
The firewall, which is the back wall of the sanctuary, is covered on both sides by a double layer of Sheetrock. (Sheetrock is a trademarked name. Did you know that?) The Sheetrock must extend from the floor to the roof sheeting without any break for nuisance things like trusses or roof rafters. The design of the firewall is such that it is not a straight, flat wall. It has angled bends in it, designed to improve acoustics in the sanctuary. It has cement blocks laid immediately on the footing. No foam blocks allowed in a firewall. The cement blocks, which are filled with cement,  will extend about three inches above the concrete floor. A wooden base plate goes on top of the blocks, and the wooden studs then go up to the top plate, which is a fire resistant wood type material. It is noticeable on site because of the red paint on the edges of the boards.
Putting the plate on the cement blocks is relatively easy. Measure the segment, cut the 2x6 board and secure it to the block base with the bolts in the cement filling. The only trick is cutting the miter joint at the proper angle, Putting the top plate in its proper place is another matter altogether. Consider - the wall is not straight, and the roof is not flat, but pitched upward. Further, the roof rafters above cannot be put in yet since they will be attached to hangers affixed to the Sheetrock wall that is not yet built. Got it?
Putting Up the Top Plate -
Temporary place holder supports are attached to span the open, truss-less area. These supports are manufactured from a 2x6 and a 2x4 attached at right angles.  Charles is carrying one from the assembly area to the lift, from which it will be hoisted into place.

Bob and Brian move the supports into place and attach them with screws into the existing trusses. Once eight or so are properly positioned, the bottoms of the supports are marked with a chalk line. The spanning supports must be placed over the places where the wall bends since that is where the top plate pieces must be joined (just like on the base plate).
A laser beam is used to locate the corner of the joint on the temporary spanning support.

Brian is holding the chalk line on the support. If you look carefully, you can see the red dot of the laser beam. Bob is holding the other end of the chalk line somewhere in the upper chambers of the trusses. When the line is snapped, all the temporary supports will have a line with which the top plate segment must be aligned.

The first long segment enters the building. Brian is using a strap with a loop to raise the right end of the board while the lift is used to hoist the other end of the board.









Brian anchors his end of the board on the far right as I view the scene. The screws holding the plate must be put in from the top since the supports are temporary and will be removed after the wall is built. After the wall is built the remaining rafters can be put in place. The roof sheeting can then go on the rafters and the sheeting will be nailed to the plate from above.













Brian crawls out on the trusses to attach the plate to the next temporary support. He gets to hang his head over to find the chalk line to make sure the plate is properly positioned. Then from this position he drills in a screw from above to secure the plate to the support.

Meanwhile, in the upper reaches, Bob and Kevin work to put the plate into position. Bob has the good fortune to be part of the structural framework until the plate can be aligned with the chalk line and more screws attached. After this segment of the plate is supported by screws, Bob gets a chance to relax his grip, but not until all the screws are put in.
















 As Brian gets a screw in, Bob progresses to being a one-arm support piece. Well, I guess his right arm is still being used as a support but he likely needed to restore the blood flow to the arm.

When Kevin got the final screw in, Bob could take a vacation, albeit a very short vacation.

I suspect if Bob did this every day he would not need a gym membership.

The first segment of the top plate in place.

On the bottom plate, a miter joint is necessary at the segment junctions. On the top plate a miter joint is also necessary but with the additional complication of the roof sloping upward. So now a three dimensional miter joint is cut using a circular saw and a sawzall, without the benefit of a jig or a stationary miter saw. After the cuts were made, the segments were secured with screws.

While the acrobats were toiling at high altitudes, Steve was busy setting the bottom plate.

The top plate as it looked when I left the site. The remaining segments were being cut when I had to leave and I am confident after seeing the high level workmanship that the rest of the plate was successfully installed. All that remains now is the matter of building a wall to connect the top and bottom plates.