Browse Forums Building A New House 1 Jul 16, 2015 10:27 am Hi guys, looks like from all the posts here I understand that sarking is needed but I can't seem to understand the difference between ceiling insulation and sarking. My contract says I have the following - Ceiling insulation rating R3.0 to ceiling area as required - Sisalation “Wall-wrap” and R1.5 to external stud walls Yesterday during my color selection they asked me if I need sarking and I declined it becaue they quoted me 2000$ and I thought I already have ceiling insulation. After I came home , I was reading through the forums and now I'm confused. Can you please advise me if I need sarking on top of the Ceiling insulation(R3.0) they have already provided? Re: Sarking under colorbond roof 2Jul 16, 2015 10:45 am Ok so from the enquiries we made sarking is like a foil wrap that goes directly under your roof sheets. Some say it's essential and some say it's not. I think the climate of where you live needs to be taken into account too. It can re direct the condensation that forms under the tin I believe and some say it can dampen rain noise yet others say it doesn't. We didn't get sarking under ours in the end, we have not started building yet. The best option is to ask some builder mates or someone in the business what they think for you and your build. Re: Sarking under colorbond roof 3Jul 16, 2015 11:05 am Yes climate does play a role in how much you need as well as the design of your house. We have insulation in walls, sarking and batts. The sarking is because we have a raked ceiling in living areas and batts can't be fitted there. We actually put sarking over the top of the whole house so some parts have both batts and sarking. We really enjoy the benefits, otherwise all our heat would end up flying out the raked ceiling roof. As it is we are cozy in winter and cool in summer. Re: Sarking under colorbond roof 4Jul 16, 2015 11:16 am We are in Queensland and we had to have sarking for our bushfire rating, but we would have taken it anyway for condensation and noise control. We actually considered upgrading it further to anticon (which is kind of like extra insulation batts sandwiched in sarking) but didn't in the end. Jen (& Dave) Plantation Bronte, Ormeau Ridge, Gold Coast QLD 12/03/2015 - Commencement... 26/08/2015 - Handover! viewtopic.php?f=31&t=76446 Re: Sarking under colorbond roof 5Jul 16, 2015 11:32 am Rikesh Hi guys, looks like from all the posts here I understand that sarking is needed but I can't seem to understand the difference between ceiling insulation and sarking. My contract says I have the following - Ceiling insulation rating R3.0 to ceiling area as required - Sisalation “Wall-wrap” and R1.5 to external stud walls Yesterday during my color selection they asked me if I need sarking and I declined it becaue they quoted me 2000$ and I thought I already have ceiling insulation. After I came home , I was reading through the forums and now I'm confused. Can you please advise me if I need sarking on top of the Ceiling insulation(R3.0) they have already provided? Where are you building? Do you have BAL ratings for building requirements (For bushfires) ? Re: Sarking under colorbond roof 6Jul 16, 2015 11:42 am goody59 Rikesh Hi guys, looks like from all the posts here I understand that sarking is needed but I can't seem to understand the difference between ceiling insulation and sarking. My contract says I have the following - Ceiling insulation rating R3.0 to ceiling area as required - Sisalation “Wall-wrap” and R1.5 to external stud walls Yesterday during my color selection they asked me if I need sarking and I declined it becaue they quoted me 2000$ and I thought I already have ceiling insulation. After I came home , I was reading through the forums and now I'm confused. Can you please advise me if I need sarking on top of the Ceiling insulation(R3.0) they have already provided? Where are you building? Do you have BAL ratings for building requirements (For bushfires) ? We are building in Brookwater, Queensland. I remember the builder mentioning that there is no bushfire requirements, but i'm not sure about the BAL ratings. Re: Sarking under colorbond roof 7Jul 16, 2015 11:45 am Are you in an area that requires a bush fire rating? If not and you are building in Queensland then sarking may not be required. It is required for BAL rated areas for bushfires and required for condensation control in colder climates. Re: Sarking under colorbond roof 8Jul 16, 2015 11:50 am You may also need sarking under a colorbond roof if you select a dark colour roof, in order to satisfy the minimum energy/insulation requirements of the National Construction Code Re: Sarking under colorbond roof 9Jul 16, 2015 12:29 pm If the builder doesn't require you to have it, then you don't need it. However, there are some distinct advantages to having a sarking type product. The sarking is at the top of the roof space, just under the sheets. It performs a few roles. One is condensation control. By restricting airflow around under the sheet, it limits condensation forming when the sheet temperature drops while the roof cavity is warm and humid. By having a downward facing foil surface, it also acts as a radiant heat barrier, to reduce heating of the roof space in summer. Personally, I wouldn't bother with plain sarking under a metal roof, but rather use a product with insulation bonded to it, as it shouldn't cost much more. These are products like Bradford Anticon. They offer a a thin insulation batt directly under the metal, and then a reflective foil surface below that. I've seen this make a huge difference when used in sheds without ceiling lining. Rain noise is greatly reduced, as the insulation damps the movement of the metal, and heat transfer is reduced as well, by the combination of insulation and reflective barrier. These products have the biggest advantage in hot climates and with darker coloured roofs, in helping keep the internal roof space cooler. By the time you have R3 ceiling insulation, you can argue that the roof space temperature doesn't matter so much, and so the extra cost for sarking isn't warranted, or that the money may be better spent increasing the ceiling level insulation. So it is a cost vs benefit tradeoff. However, if there is ducted air-condioning in the roof space, roof level insulation reduces the temperature of the roof space and consequently there is less heat gain through the ducts. The structure of the roof may also last better, together with all the wiring, plumbing and A/C etc that's in it, as it goes through less thermal cycling, and is subject to less heat. Building Standards; Getting It Right! Hi all I’m in VIC and had some storm damage in my garage a month ago. Gutter found not fit for purpose. Insurance company saying the guttering and flashing to be fixed… 0 11712 Your house roof does not show rusting other than some surface rust on the flashings. In my opinion you dont need to replace or paint the roof other than treat surface rust… 1 10206 You should pressure clean your roof first and make sure the paint you buy also is anti mould. 4 18563 |