West elevation cladding continues
July 3, 2016
We are now working our way along the west elevation completing the larch rainscreen cladding.
The door revels are dealt with much like the windows in so much as they are wrapped in Pro Clima Fronta Quattro breather membrane (which is suitable for underneath an open rainscreen cladding like ours with 6mm gaps between the boards), and the joints are lapped and taped using Pro Clima Tescon Invis. This overlaps the Pro Clima Extoseal Encors weatherproof flashing tape we used at the base of the door and window reveals to make sure that any water behind the cladding can be drained away properly.
Later we will clad the reveals themselves...
The next part we
tackled was the base of the corner. These photos show the sequence
required to get the appearance of a mitred corner but with the open
rainscreen having a 'soft' joint i.e. the two pieces of timber not
touching (more photos of a completed corner to follow in another post!).
Firstly the battens were covered in black insect netting - we used a fine 'midge' grade. Mainly we used this as we have wood fibre insulation behind the cladding so want to prevent any insect ingress at all.
Due to the height of the wall below the corner window the membrane just laps right up to underneath the window cill. The batten spacing is determined by the studs internally, but with a min. 600mm between centres.
The two vertical battens in the corner need to be connected with a shaped base and top piece, tapered in section to allow the rainwater to drain. It was easier to pre-staple the stainless steel insect mesh for the base of the wall / directly under the window cill to this corner piece in advance of fitting it.
One at the top...
One at the bottom.
This is just a view from above...
... and below showing the mesh in place against the breather membrane.
As there isn't any structure right at the external face of the corner of the wall due to the 100mm thick Gutex layer the end of the cladding boards cantilever beyond the last timber batten. To prevent them moving too much as they go through the wetting and drying cycle, and to keep them evenly spaced over time, we used a stainless steel strap and very short (20mm) stainless steel screws to connect them together. This was rebated into these little corner pieces we had made earlier.
The insect netting is continued over the face of the stainless steel strap.
We left enough spare to wrap it around to the first vertical timber batten on the adjacent elevation.
Then we had to 'pre-fabricate' the last few boards as they are too small to be nailed onto the battens and we needed to connect them to the stainless steel strap you saw earlier.
The view from the front.
Finally this little corner piece was screwed onto the stainless steel strap from the back. Obviously this method of fixing only works from one side of the corner so I will post more later on making up the full corner...