Browse Forums Heating, Cooling & Insulation Re: Effect of excess batts on room temperature 11Dec 17, 2009 10:07 am themax Oh that looks interesting JilaMint? Too late for us now, but I am interested in what anyone can tell us about them. Yeah - I only came across these the other day. They do look very interesting. Why do you say "too late for us now" ? The whole idea of these is that you install them after construction (after handover). They look much easier to install than taking a rolled up sheet of RFL sarking and trying to cut it to fit while up in a cramped roof space (you would need some serious origami skills for that). @ $100 for 20sqm coverage (or $5per sqm), I think that is comparable in price to decent RFL sarking. Eccles I wish I had his roof space. Usually they are cramped and tight and definitely can't use a ladder in there. And it is interesting to see that he is fitting the concertina foil as a second radiant barrier under the sarking (probably because the photo is from a site that sells foil). You can also get narrow rolls of radiant barrier - typically used for insulation subfloor - that might work in the same fashion. The concertina profile does not increase its effectiveness. Try the local large hardware store. However larger span sheeting would work in this roof space - especially in the bottom section. It depends on what the roof structure is as to what is quickest to install. Good points. The picture is from the site that sells them (and other foil products). I agree, I don't think the concertina profile will increase effectiveness - just the expanding/contracting nature makes it easier to manipulate between the rafters. Also, there is an unusual amount of roof space and clearance in the photo (I imagine to enhance the appeal of "look how easy these are to install"). Re: Effect of excess batts on room temperature 12Dec 17, 2009 10:15 am We already have sarking and insulation installed in the roof. www.themaxbuild.blogspot.com forum.homeone.com.au/viewtopic.php?f=31&t=20717&start=300 www.leahspaperpassion.blogspot.com Re: Effect of excess batts on room temperature 13Dec 17, 2009 10:22 am krangsquared Thanks for the replies. I found out about the pile of insulation because I am planning to install sarking/ reflective insulation in my roof area, under the rafters. I will look at spreading out the batts after I've installed the sarking. =) If you have an overheating problem often it is not just one cause or one cure. If your roof is letting in say 40% of the heat and you cut this to say 20% it still means a lot of heat can be getting in from other areas and the overheating only partially addressed. So also look at things like unshaded Northern and Western (and Eastern) windows that allow sun light directly in. Look for air leakage around window frames, doors and elsewhere. This applies to the whole house as (as you have discovered) heat entering anywhere in the house will tend to go to the top storey. Re: Effect of excess batts on room temperature 14Dec 17, 2009 10:56 am Eccles The concertina profile does not increase its effectiveness. I should have said "The concertina profile does not increase its effectiveness in this usage". If the concertina foil is laid directly on top of insulation batts in the ceiling (another way of using them) the concertina shape is highly important as it provides an air space between it and the batt. All radiant barriers need an air space to work. Re: Effect of excess batts on room temperature 15Dec 17, 2009 6:03 pm krangsquared - The only real way that I can see the pile of insulation could be adding to you heat problem is by the extra efficienies in that area of your ceiling and I assume that it is more over one room - is the overnight/cooler day time looses would be less - so you have a lower rate of heat loss from the room - which equals - it feels hotter with any heat that gets in there. Re: Effect of excess batts on room temperature 16Dec 18, 2009 12:30 am Eccles: Wow. I was not at all aware of construction techniques used in your part of the world. Your posting was indeed a very enlightening one for me! Thank you! With only my North American perspective, it seems the attic is the least of the original poster's worries, since _I'm_ the one full of hot air! HEHE! Cheers! James. Re: Effect of excess batts on room temperature 17Dec 22, 2009 12:14 am James, No worries. I've done a fair amount of research into the issue of using sarking, so that matter's pretty much already settled for me. I was really just wondering about the excess batts that I had and if it was making things worse. JillaMint, From the previous posts in this forum, the general idea I got was to just get the cheapest possible sarking, as long as it doesn't tear easily. =) And there isn't much difference between .03/.05/.07 emissivity, so whatever is available should be fine. I was planning to get Sisalation from my local Bunnings but they didn't have any, so I just got Tradewrap wall wrap foil insulation, which is also from the same manufacturer (Fletcher Insulation). My roof space is really cramped so it's going to be a bit of a struggle to install the sarking. All the installation diagrams and photos I've seen are always showing these spacious roof cavities, while I have: Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ The pile on the right is the insulation I was talking about. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Makes me wonder if the concertina batts will be any easier to install! Re: Effect of excess batts on room temperature 18Dec 22, 2009 9:52 pm Quote: Makes me wonder if the concertina batts will be any easier to install! Certainly will be - and is only in the order of 0.3 less effective than the tough option. PM me your email. I have a build excavation calculator you can use based on your plans to double check what your builder is telling you. Cheers Simeon 1 10331 Found the answer. The recommended distance is .... 1 6041 |