Glulam posts installed!
October 10, 2014
This week we installed the glulam posts that will form the support for the side of the staircase and the balustrade... With some help from a few family members these 5.9m long posts of various sizes were lifted into position and fixed in place at the top and bottom of the double height space.
The first step in the process was to install an area of the Intello airtight membrane to the ceiling - this is stapled in place directly to the joists, each staple is covered by a piece of airtight tape, and the perimeter is taped to the adjacent pieces that are already in place above the wall heads. Martin's brother did a very neat job with his first airtight membrane installation!
We then fitted a sheet of the Gypsum Wallboard that forms the fire protection to the roof, and a rail which was also fixed through the membrane to the joists, to enable the posts to be offered up to one side of this which allows for some adjustment when checking that they are plumb.
Starting at the front edge of the stair there are 7 of the 5.9m tall glulam posts which alternate with smaller posts that create the spaces between - in accordance with the technical standards the space between any balustrade pieces should be no larger than 99mm. We have designed our stair so that one tall post and one small post are exactly the tread depth. This alternating pattern of light and dark (or solid and void) is repeated up the whole flight of stairs and forms a central 'wall' that the stair wraps around.
Each of the posts was glued and screwed through into the one before so that the fixings are hidden, and the whole assembly was fixed to the ground floor slab with L-shaped brackets via a rail that was plugged and screwed into the slab.
We then had to repeat the process on the first floor as there is another short wall that forms the guarding to the top of the stair from the landing level and we have designed this to be a similar wall of posts to create patterns of shadow and light on the first floor.
Finally this meant that the landing could be properly finished off and supported on another horizontal rail which is fixed into the vertical posts with coach screws, all of which will be concealed by our lower ceiling level within the inner 'box'.