The GIB going up really feels like a milestone. Like I say over on stuff.co.nz this week, walls just make the house more….houseified. I talked about getting the plasterboard onto site over there (so glad that wasn’t my job) but for those of you interested in more of the detail on this part of the process I thought I’d go into the products a little more here.
Interior magazines are full of glorious bathroom designs with fully tiled showers and walls, but because we just couldn’t squeeze that into the budget, we’ve gone for Athena Acrylic Lifestyle showers coupled with GIB Aqualine®. When we were looking at buying a house rather than building, many were the bathrooms we walked into and realised that steam, moisture and bigger sneaky water damage had destroyed what would have been a nice room. This new build (like most of them) has been a long, expensive process so we don’t want to have to repeat or repair anything for a long (long) time. The GIB Aqualine® has a water resistant core containing special polymers to help prevent steam and moisture penetration so we’re hoping it’s the best insurance against future liability and expensive call-backs.
If you are planning on tiling your bathroom though, it is the top tiling substrate used in bathrooms too. Strengthened with a fibreglass core, it provides a solid stable backing so you can go for gold. Gold tiles that is.
On the ceiling we’re using GIB Ultraline®. The modified core with plaster and fibreglass provides density and rigidity and it’s got a special Pearlcoat coated white surface paper, (doesn’t that sound smooth already – Pearlcoat) making it easier to get a higher finish quality. With all the light coming through our windows that ceiling is going to show everything, so the higher the finish quality the better as far as we’re concerned. Especially as Mr BuildingBoxes is going to be going for gold paiting that ceiling in a couple of week’s time.
And finally, along with the standard GIB plasterboard, we’ve got dual board GIB Braceline® GIB Noiseline®. Its higher density core can reduce noise transmission between rooms and also between floors in two storey homes – important when our two boys turn into heavy footed teenagers. It’s formed part of our bracing structure too – a cost effective way to add to the bracing of the building – win win.
Now it’s down to GIB stopping, and then….painting. Can’t decide if I’m excited about seeing colour start to coat the walls, or terrified about putting my roller and paintbrush to work again!
Yes, really. While over on stuff.co.nz this week I’m talking about the unexpected bonuses of housesitting (and a little on the downside of the constant packing and repacking), we’re still insulating. This time, downstairs with a great new (to New Zealand) product, DriTherm, again from Knauf. It’s part of the Earthwoold glasswool range and is specifically for masonry walls and cavities.
If you’ve been following along a while you’ll know that we have 50mm of ClimaFoam XPS on the outside of the blockwalls, and now with the DriTherm on the inside, we’ve bumped our Rvalue up to R3.3. With the added insulating properties of the block walls we should be toasty warm down there now. And I should add dry, cos while we’ve made sure to seal out the moisture in a bunch of ways, it’s nice to know the DriTherm won’t transmit water into the inner leaf as a double check. While we don’t need to dampen down the sound much on the wall that’s effectively buried in the bank, DriTherm provides great acoustic benefits too so hopefully those gleeful screams of The Lego Engineer and Destruction Specialist celebrating finally having their own lawn, will be damped somewhat.
Like the standard Earthwool glasswool we used upstairs, this stuff is super easy to deal with. All it takes is a measure, cut and place and it’s all done. I have to admit that it did take me longer than upstairs simply because DriTherm is stiffer and so doesn’t provide as much opportunity for measuring by eye – which is of course, my preferred method. The rigidity comes from its silicone treatment and because of that you can see every cut, nook and nick, so I had to get busy with a straight edge and measuring tape which simply takes more time. Once you’ve cut it to the exact size however, it just stands up nice and neatly in your chosen cavity until you cover it up. Job done.
It feels like things are starting to pick up and the place is really starting to look and feel like a house. Yeay! Over on stuff.co.nz this week I'm talking about the air tightness system from ProClima that we've installed - another of the Passive Design principles we've chosen to adopt in the build. As I keep saying we are not trying to achieve PassivHaus standard because we simply cannot afford it. To put it in context: getting the right windows on our build to meet the standard, we would have meant adding more than 20K to our bill (that's over and above the double glazing, LowE glass windows we already have, I'm talking ones that are truly air-tight - but that's a whole other post that I'll come to when I talk more about numbers).
We have, however, been able to put in the air tightness system and we're already feeling the big change in warmth in the building - and we haven't even got the real doors in yet! Seriously, while there is white ice all around outside (which doesn't happen often in Auckland) it's pretty warm inside, and like I said, that's without proper doors and the garage still being open.
In case you're not heading over to stuff, the basic principle of the air tightness system is giving our insulation the best possible chance of keeping us warm. It's a Goretex jacket over a woolly jumper - keeping all the warm in but not letting the cold air outside steal it and make us need to heat the house with means we need to pay for.
The process is relatively straight forward: cut Intello pieces to fit, staple them in place and tape the puppy every which way to Christmas. We also need to tape or fill every nook and cranny we can find, so around power points (where there are special boxes to help with the job), doorframes, floors, ceilings, you name it, we're trying to seal it up. It’s another job we’ve done ourselves with staple guns, a sharp pair of scissors and some seriously specialised tape from ProClima.
We’ve had to think hard about plumbing and wiring – keeping as much of that in the internal walls as possible, because every time we make a hole we have to seal it up. Real good. In the ceiling however, we got round that problem by creating a service cavity, fixing the Intello directly to the frame and then using GIB Rondo battens to create the cavity for wiring and light fittings.
We’re not experts, and a few insulation installers do put it in, but it’s a pretty specialised product so it’s not like the yellow pages are crawling with installers yet so it’s hard to gauge how much we might have saved putting it in ourselves, but to put it in perspective it’s taken Mr BuildingBoxes about four and a half days, plus the blower door test (which is definitely outside of our scope). And speaking of blower door test, if you have popped over from stuff, here are the edited highlights with Jon Davies from ProClima New Zealand.
Happily yes, we did manage to crack the rating we were hoping for, less than 2ACH, which wasn't bad considering, as I said, we've still got work to do. The process of course is to do this test now, while we can access the membrane and seal up any obvious leaks. Then when the linings have gone in and we're almost there, we'll test again to see how we're doing and the rating should drop again. So 2ACH at this point is great, compared to anywhere from 5ACH in a great new build house to 10ACH in a pretty standard one. Should save us plenty on powerbills as we manage to use the heat we've gathered in the insulation and the thermal mass in the concrete slab rather than turning on the heater! And just in time, it's been COLD this winter!
A family of four: writer, scientist, lego engineer and destruction specialist. Our previous home is featured in New Zealand Interior Style and this new project promises to provide plenty of great, green, smart and maybe madcap solutions to new building in New Zealand.