Browse Forums Heating, Cooling & Insulation 1 Mar 13, 2010 12:23 pm Hello, We are in the colour selection stage and are in a dilemma over whether to choose dark or light coloured roof tiles, with particular respect to keeping the house cool through summer (we are in Brisbane). From research and common sense we understand that lighter coloured tiles will absorb less heat, but we're not sure just how much of a difference we're likely to see between the two colours. It's a two storey house with R2.5 ceiling batts and sarking to external walls. Lower storey is exposed brick and upper storey is lightweight weatherboard cladding. The dilemma comes from the fact that we much prefer the look of a darker roof, and so we're trying to weigh up between a (possibly) hot but lovely looking house and a (possibly) cooler house with a little less street appeal. We hope to have the house temperature manageable without relying on air-con too much. So, can anybody shed some light on just how much of a difference lighter roof tiles will make as opposed to dark, given that we'll have insulation up there too? Thanks very much in advance! Re: Worth going for light roof tiles over (nicer looking) da 2Mar 13, 2010 4:07 pm If you are really keen on the dark roof tiles then you could upgrade the insulation. R2.5 would be the recommended minimum, so upgrade to 4 perhaps for the roof and then 2.5 for the walls instead of the standard. Internal insulation as well would help I think. Re: Worth going for light roof tiles over (nicer looking) da 3Mar 13, 2010 8:45 pm Foil under the roof (any colour) will block out >99% of radiant heat. A white roof blocks out about 50%. White roof + foil gives only a slight incremental benefit, it will reduce the remaining 1% of radiant heat by half. It might also keep the AC ducts in the roof space a bit cooler and improve the system's efficiency. Re: Worth going for light roof tiles over (nicer looking) da 4Mar 15, 2010 11:30 am Thank you both for the replies. Dymonite69, do you mean that basically as long as you have the foil underneath the tiles, the tile colour would make very little difference since the foil reflects back 99% of the heat anyway? If so that's definitely good to hear. I would have thought that wouldn't be the case since you often hear people say to choose a light roof colour? Fernyhouse, I'll ask the builder about upgrading the insulation. Any idea what the cost would be like while I wait to hear back from them? Is this something that may be cheaper to get done after the handover and therefore avoid the builder's margin? I'd imagine upgrading the roof insulation might be relatively easy but getting into the walls would prove more difficult and may be better done while the house was being built? Re: Worth going for light roof tiles over (nicer looking) da 5Mar 15, 2010 12:06 pm There is not much individual benefit from white roof if you already have foil underneath. However, if everyone had a white roof this would reduce the urban heat island effect that raises the outdoor temperature. You may a slightly cooler roof space with foil AND white roof because you have reduced some of the heat load before it enters. However, the effect on the temperature below the ceiling would be minimal. Re: Worth going for light roof tiles over (nicer looking) da 6Mar 15, 2010 12:19 pm Excellent, thanks for the clarification. I've asked the builder for more info as to what insulation we are getting as standard, as I'm not too sure if there is sarking under the roof or if it's just in the external walls. If it doesn't come with roof sarking as standard, it's starting to sound like an essential extra to have. Re: Worth going for light roof tiles over (nicer looking) da 7Mar 15, 2010 12:31 pm StartingOut Excellent, thanks for the clarification. I've asked the builder for more info as to what insulation we are getting as standard, as I'm not too sure if there is sarking under the roof or if it's just in the external walls. If it doesn't come with roof sarking as standard, it's starting to sound like an essential extra to have. Think about which part of the house gets the most sun. The roof cops a big radiant heat load. Foil is mandatory in any place with hot summers. Re: Worth going for light roof tiles over (nicer looking) da 8Mar 15, 2010 2:23 pm Ok, I just heard back from the builder and they quoted $1600 for sisalation under roof tiles, $200 to upgrade ceiling insulation from R2.5 to R3 and approx $280 to install a whirlybird. Sounds like the jury's very much still out on whirlybirds, but the sisalation is definitely something we will need to consider. (is sisalation the same as sarking?) Would an upgrade from R2.5 to R3 for the ceiling insulation make a noticeable difference? Thanks for the continued help. Re: Worth going for light roof tiles over (nicer looking) da 9Mar 15, 2010 2:49 pm StartingOut Ok, I just heard back from the builder and they quoted $1600 for sisalation under roof tiles, $200 to upgrade ceiling insulation from R2.5 to R3 and approx $280 to install a whirlybird. Sounds like the jury's very much still out on whirlybirds, but the sisalation is definitely something we will need to consider. (is sisalation the same as sarking?) Would an upgrade from R2.5 to R3 for the ceiling insulation make a noticeable difference? Thanks for the continued help. I believe sisalation is a brand of sarking Re: Worth going for light roof tiles over (nicer looking) da 10Mar 15, 2010 7:16 pm StartingOut Ok, I just heard back from the builder and they quoted $1600 for sisalation under roof tiles, $200 to upgrade ceiling insulation from R2.5 to R3 and approx $280 to install a whirlybird. Sounds like the jury's very much still out on whirlybirds, but the sisalation is definitely something we will need to consider. (is sisalation the same as sarking?) Would an upgrade from R2.5 to R3 for the ceiling insulation make a noticeable difference? Thanks for the continued help. That R2.5 would be blow-in, i'd go for R4 batts if your going to upgrade. I asked my builder if i could come in and put insulation in the walls before the plaster went on, he then informed me that it comes standard with R1.5 batts in the walls to meet the 5 star rating. I have upgraded that to R2 in the walls for an extra $190, as thats what i was going to put in. Re: Worth going for light roof tiles over (nicer looking) da 11Mar 16, 2010 9:29 am Thanks for the replies. The R2.5 is apparently ceiling batts, not the blow-in stuff. We might consider upgrading to the R3 batts though. Hi I am wanting some opinions about the build of a steel shed I am going to get one about 4.5 x 2.5 m steel shed and the height will be about 2.3-2.4m high The one I am… 0 14442 Hi All, I am looking to go with tiles instead of laminate timber flooring throughout my living areas for my new build (Ashbury 29 - Henley). My whole colour scheme is on… 0 24349 Cheers. The painted render is a bit chalky to the touch. To prepare the surface for best adhesion, what would you recommend? Also, given that there must be some… 6 8509 |