Catch-up Blog 15: Foundations (Oct/Nov 2018)

With piles in place and the earthworks to prepare the building platform completed it is time for the profiles and the formwork (boxing).

During this period, we had our first major caravan and awning test with a major southerly storm sweeping across New Zealand. It dumped about 200mm of rain in a couple of days in Hawkes Bay with gale force winds. And we found that the positioning of our caravan with its side facing South, while ideal in most respects, meant that strong winds blew straight into the ventilation grills spread along that side of the caravan for all the gas appliances - in this southerly gale it was nearly as windy inside as out! The awning also took a hammering, but survived thanks to Bob’s help in putting it up, with big steel waratahs instead of aluminium tent pegs and well guy roped corners… An amazing experience for us both huddling under the blankets in a rocking caravan like we were bobbing in a yacht in the roaring forties.

Back on the building site, we learned that the first step for the foundations, the “profiles”, are critical for measuring and marking off where walls and plumbing / cabling will be located, so that the services can be built into the foundations in the exact spots to be inside walls etc..

Everything we were yet to build would refer back to the accuracy of these initial profiles, so really critical…

The corner profiles were setup by MPT (the concrete contractors) and they also set the final level for the base of the foundations, using our datum already setup for the earthworks and a laser level to spread out a final course of lime sand. They were then straight onto putting up the formwork for the foundations; using ply formwork, steel waratahs and boxing braces that made the job simple and fast. Watching what was involved and the gear they had we soon appreciated Pat’s advice to get experts in to do this rather than tackle it ourselves.

Pat then marked up profiles on the formwork locating our internal walls, the kitchen island etc.. and these were then used by our plumber Kenny to set out where his plumbing was located. Kenny and Ayden then trenched out and laid the plumbing inside the foundation formwork, had the job inspected by council and backfilled it with pea metal, their work quality and work rate was really amazing.

MPT then picked up, laying the Cupolex thermal mat, Cupolex pods and the reinforcing steel. Again, watching them tie off the reinforcing with hand guns vs “by hand” made it abundantly clear why we had a specialist team on this job.

Then it was time for ready mix cement from Bridgemans… we had it booked for a Thursday, but a snafu on ordering and supply of the black oxide liquid colour for the mix meant that it had to be pushed back to the following Monday. Frustrating at the time as it broke the flow, but in hindsight a blessing…. a blessing because when concrete is laid it needs to be kept wet for several days during its initial curing, this is critical, and as luck would have it Thursday dawned with our spring water supply out of commission, so no water on-site. Thanks to quick action from Mike and Kirsty our water supply was restored by Friday, so we would be ready for the cement - a close call!

As Monday approached the weather forecast made it a nail biter, and in the end we decided on Sunday to plow ahead.

The team from MPT were on-site at 5:30am Monday with a concrete pump truck ready to pour. The day dawned with an updated forecast for rain in the afternoon, hopefully we could get it poured and screeded off before it arrived.

The Bridgeman’s ready-mix trucks had quite a drive out to the site from town, so we had a few pauses along the way waiting for trucks and this didn’t help the weather anxiety levels... we pushed on. The cement was pouring really black, great ! just as we wanted it for thermal gain.

The second ready-mix truck up was driven by Richard, my sister’s ex-husband, really good to catch up with him, and then Mike from MPT arrived with smoko for everyone from town - great! we weren’t expecting a visit from the boss and appreciated the care shown for our job.

In the end, the rain arrived about an hour earlier than we would have liked but within our “it will be ok” zone i.e. not a fail, whew… and this moved us into the next task of keeping the slab wet, after days of praying for the rain to hold off, lol…

We had agreed with the concrete grind/polishing contractors that we would pond the slab for 7 days before they arrived to grind. “Ponding” is where the concrete slab has a dam built up around the edge (using expanding foam, or in our case limestone sand as the foam method failed) and a pool of water is maintained over the entire slab.

This meant 7 days and 7 nights… it was like having a baby again, waking up and checking in the night, repairing breaches in our dams.. and refilling the pond. Our water supply was limited and the combination of sun and heat from curing caused rapid evaporation while rain showers would often wash away our dam edges. Late in this week the MPT team came back and stripped the formwork off the foundations, and after several hot weeks, and weather tension on the day of the concrete pour, it was a pretty ideal week for concrete curing, generally cloudy with intermittent rain showers.

Now the final phase for the foundations could kick-off. We had Byron Cash and his grind guru’s team, Pat our builder, and Kenny and Adyen from Advanced Plumbing all arrive ready to go first thing on Monday morning. There was a little traffic jam first thing as we sorted out site access and parking, possibly a first traffic jam for Maraetotara, but this was quickly sorted and it was full steam ahead.

Byron Cash’s grind guru’s team put in two day’s solid work levelling the floor with their grinders and getting a nice consistent finish of aggregate in the slab revealed, to “salt and pepper” level. They had all the right gear, with diamond grinding machines and a lot of skill to demonstrate why they are indeed the gurus of grind! We will welcome them back later for the final polish and seal after we have the internal walls plastered.

Kenny and Ayden from Advanced plumbing came back and finished off the pipe work outside the foundations for our waste and stormwater. They had the 5-tonne digger, laid a lot more pipe, another council inspection and then backfilled.

Amazing what Kenny and Ayden achieved in a single day’s work - grey and black water connected from the house back to our Waterflow NF8000 waste system, stormwater run back to the rainwater tank with downpipe risers in place and outside taps installed - all council inspected and approved! Kenny also helped with trenching in/out power and restored the work site to roughly level so we had a good base ready for the mobile scaffolding we would need to put up the framing.

While all of this was going on, my father Bob and uncle Geoff (with some help from the advanced plumbing digger) trenched and pulled through the power cables into the house ready for connection to the meter board.

There were a few challenges with the final duct in the foundation as it had ended up with a partial S bend rather than a simple bend, and we had some big inflexible mains cable to pull through - difficult… but we got it through!

A great start. Good foundations are key to our house performing well as a passive solar design and having services in the right places is a must.. no toilet, no water, no power are all showstoppers that would be very difficult (and ugly) to remediate when we have a solid concrete slab floor.

That’s us caught up, the next blog post for framing will cover what we have been doing in November and December as we head into Christmas… so we are onto a real time footing for the end of the year.

Catch-up Blog 15: Foundations (Oct/Nov 2018)

1281 Maraetotara Road, Maraetotara RD12,

Havelock North 4294, New Zealand