Browse Forums Heating, Cooling & Insulation Re: Roof insulation and Anticon blanket 5Sep 07, 2022 1:10 pm For compliance with NCC section J (energy efficiency), you need R3.7 total if you're going for a simple DTS compliance method. That includes everything from the inside to the outside: *the film of air against the ceiling *the plasterboard *the ceiling insulation *the air inside the roof space *the roof insulation *the roof material itself *the film of air against the outside of the roof It's odd for any builder to be including R3.0 roof insulation (130mm thick). Any thicker than 100mm will require roof spacers to avoid the sheeting buckling under the springiness of the insulation. Fitting spacers is labour-intensive and most builders avoid it like the plague. It's common to use R1.3 (60mm) anticon roof insulation in place of sarking because it's thin and easy to install, and then make up the rest of the R-value with ceiling insulation. If your raked ceiling means you'll have minimal space for insulation, this could be a reason to go with roof spacers. Personally I'm a fan of structural insulated panel roofs for raked ceilings. It gives you huge R values and muffles sound really well (ever heard somebody yell in a cold room?). If you're getting NCC section J compliance with the JV3 method (thermal simulation of the building) instead of DTS, you have full flexibility to break the rules on R-values. You just need to have a design which the simulations show is more efficient than if you HAD followed the DTS rules. If your building is efficiently designed in some places, it gives you wiggle room to be less efficient in other places. The JV3 method is more expensive than DTS but it can pay for itself easily through saving on materials and labour costs. Sometimes JV3 is necessary anyway because the specific building needs to have no floor insulation or a dark roof or wall colour that DTS doesn't allow. If you're getting a JV3 section J certification, don't worry too much about giving them a building which is already efficiently designed. The consultant doing the JV3 certification should consult with you (that's what consultants do) on the cheapest ways to improve the building. You're in climate zone 5 so the best thing you can do for energy efficiency is plant an apple tree just north of your house. It shades the house in summer but loses its leaves in winter to let the sun provide free heating. Hey guys building a new place through a volume builder and just wondering if i should complain to the site supervisor as we just had plasterboard installed. Looks like… 0 11279 1000000% definitely add insulation. I have in my home and it makes a big difference minimising sound transfer. Insulation is pretty cheap and definitely worth it 2 6211 |