Browse Forums Heating, Cooling & Insulation 1 Sep 09, 2009 8:14 pm Hi everyone As an owner-builder, I'm realising more every day that there are 1000001 things you need to remember to do, otherwise its too late and you have to work around it! Our house is mainly one story and all external walls on the ground floor are double brick. I've used AirCell Glareshield in these as insulation. The master bedroom is upstairs and the walls are brick veneer. Unfortunately I was so caught up in getting the bricklayers to finish, I competely overlooked the need to put sarking/wall wrap around the frames and now I'm not sure what the best option is. The plans and our EER specified R2.0 batts plus sarking. Now I'm thinking of going with R2.5 batts to compensate for the lack of sarking. Is that going to be a problem?? Does anyone have any other suggestions? The roof is also on upstairs, so no option of retrofitting sarking in that way... Help?? Re: I forgot the sarking! :( options?? 2Sep 09, 2009 8:21 pm The sarking acts primarily as a moisture barrier rather than for the R rating it adds. Re: I forgot the sarking! :( options?? 3Sep 09, 2009 8:24 pm Dukekamaya The sarking acts primarily as a moisture barrier rather than for the R rating it adds. Will the batts not be sufficiently effective as a moisture barrier?? Are there certain batts which would be better from that perspective? Any other options?? Re: I forgot the sarking! :( options?? 4Sep 09, 2009 9:31 pm The batts will not stop the moisture from being transferred. They are a different product from the sarking Re: I forgot the sarking! :( options?? 5Sep 09, 2009 9:53 pm Dukekamaya The batts will not stop the moisture from being transferred. They are a different product from the sarking Hmm...so do you have any suggestions for a suitable solution?? Re: I forgot the sarking! :( options?? 6Sep 09, 2009 10:19 pm I'm not too sure, unfortunately the wall wrap goes on before the weatherboards go on or the bricks are laid. Same goes for the anti-con going on before the metal roof Re: I forgot the sarking! :( options?? 7Sep 10, 2009 12:27 am Dukekamaya I'm not too sure, unfortunately the wall wrap goes on before the weatherboards go on or the bricks are laid. Same goes for the anti-con going on before the metal roof I guess I'll just have to find the most water-resistant batts i can and take me chances....! Re: I forgot the sarking! :( options?? 8Sep 10, 2009 7:55 pm Does anyone else happen to have any suggestions?? Re: I forgot the sarking! :( options?? 10Sep 11, 2009 9:49 am I talked to CSR Bradfords recently as I'm putting insulation in an already built house (so similar problem to you). They said not to use a moisture barrier or sarking because unless you have it over the studs as well it doesn't work (considering I only have the internal walls off and not the external I can't cover the studs). They said: "If you can’t access the whole wall, I would not recommend using EnviroSeal. The insulation batts you install will need to be strung to the joists to ensure they do not fall back onto your cladding as moisture may be transferred though." So my plan is to string the insulation up so that it does not touch the external wall (leaving 10mm gap). I'm also using rockwool insulation but I haven't read anything definitive yet as to if it is moisture resistant or not. Re: I forgot the sarking! :( options?? 11Sep 11, 2009 2:53 pm The RFL has a thermal value of around 0.43 when facing a cavity & used in conjunction with wall batts. Increasing the batts from R2.0 to R2.5 should compensate. In a brick veneer construct the 'bigger' benefit of the RFL is to contain the insulation batt to the stud space. You would need to string the face of the stud in the cavity to make up for this. (There is no requirement for a vapour barrier in a brick veneer situation - the cavity provides the break) Check with the energy rater who did the original assessment to make sure R2.5 will suffice. Peter Clarkson - AusDesign Australia www.ausdesign.com.au This information is intended to provide general information only. It does not purport to be a comprehensive advice. Re: I forgot the sarking! :( options?? 12Sep 11, 2009 5:31 pm Thanks very much for the additional comments and advice; definitely makes me feel a bit more comfortable!! I'll be stringing the stud wall to keep the batts in place and, as much as possible, confined to the stud (88mm batts in 90mm stud). Also, now thinking of using Dulux Elastomeric exterior paint, which is in effect an elastomeric membrane, virtually moisture impermeable (10.6g/24hr/m2/kPa) and extremely crack resistant. That is on top of polymer modified render - if that doesn't do the job, not sure what will! Thanks again, Adam Re: I forgot the sarking! :( options?? 14Sep 19, 2009 11:32 am Hills Guy Another option would be to use the spray-in expanding foam. It is very popular in the USA, but I dont see it very often over here (other than in airosol cans for small jobs) We got a quote once. Fairly expensive ~ $25/m2. The structure needs to be modified. You still need sisalation as a backing to spray the foam onto. http://www.insulfoamsolutions.com.au/Pa ... rview.html See the installation brochures. Re: I forgot the sarking! :( options?? 15Sep 19, 2009 11:42 am Sorry I meant $50/m2. You get the same R value. The only apparent advantage is the avoidance of thermal bridging or convection currents. 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 1134 I ran into trouble finding a lock that would fit my particular door, like your situation with your pivot door. I wanted a safe lock that couldn't be messed with easily. 4 25704 Standard uninsulated double brick has an R value of around 0.7. An insulated standard 90mm stud timber frame can have an R value of around 2.7. Even if you insulate a… 17 10156 |