Over the weekend, I've started a job to install a flashing system and some framing timber to support a new cladding system to our house.
This was the state of the brick cladding following the Feb 22 Chch 2011 Chch quake.
The brick has been removed, Batts installed in the external walls, then building wrap, then Ecoply. The house was built with rimu 4x2 framing. In those days there was no prefab laserframe, so it would have always been uneven, and of course with brick cladding, it didn't matter. I have repaired the foundation, including epoxy to inject small cracks, re-levelling the top of the foundation in conjunction with jacking floors level (maximum about 40mm) and replacing 8 foundation piles, a builder did the work replacing the piles.
With "leaky homes" the councils are absolutely anal about water-proofing. My consented design required the following over the top of the foundation, before fitting a flashing system. The top of the foundation has a tanking membrane applied, then there's a DPC, then under it is a 5 deg beveled H3.2 treated timber support. This caused me a few nightmares, but I bit the bullet and bought a bench saw so I could rip timber as required.
Over this goes a a grade 5008 aluminium flashing. A major problem with this is that the gap between the edge of the foundation and the framing varies. I am getting the flashing supplied in custom sized folded sections. This weekend was "test of principle" - I didn't know if it was going to work.
So there's the flashing in place (the flashing is dead straight - it looks not that way due to lens distortion), the new timber above are "extra" H3.2 battens needed to pack out over the framing, to allow 95mm for the depth of the new cladding, which is a custom poly/plaster system 75mm designed specifically for re-cladding of brick homes, attached over 20mm vertical battens on top of that timber. The sheets are laid horizontally, staggered - so there are no full-height joins. The stud spacing isn't even - but about 450mm, so less than the 600mm maximum spacing I need. As the flashing was going to obstruct the top of the sub-floor vents, and some of the vents had been broken, I replaced them all, and reset them down about 25mm.
This is the area where I installed the flashing system and the "battens" packing timber this weekend. I used 4 string lines with 3mm spacers. Each piece is a slightly different depth. I had to pre-measure with a test jig I'd screw to the framing, then rip a 75x45 H3 to depth, then make "fine tuning" adjustments to allow for the bumps and curves in the original framing using an electric planer - and without bending the timber as it was fastened. The battens are screwed into the 50YO rimu studs with 14 gauge self-drilling galv batten screws at minimum 300mm centres. My old battery drill was not up to the task, so I bought an 18v brushless impact driver, which does the trick - no smoke has come out of it yet.
I have uncovered an issue with the consented plans - we'll need to change window jamb flashing details. Not a big deal.
I'm happy I've got the packed framing +/- 1mm. The framing was +/- 5mm.
I have other contractors coming this week to remove a 30m2 3m high concrete deck (this to be replaced with a timber deck). The combined weight of the brick cladding, concrete deck, chimney etc was over 50 tonnes. My objective since the EQ was to carry out repairs with additional strengthening and weight reduction a priority. It just seemed crazy to me to not do this, but it sure as hell would have been easier to just re-brick it.
So all good - I'll meet with my builder over the next couple of days to work out how we'll organise to do the rest of the house (flashing/framing). I'm also confident that the plans are workable, so can order materials. He's just done a similar job, but using different materials and design, and like me was concerned that the architect / designer I used may have underestimated the difficulty.
I'm now happy it can be done.