Browse Forums General Discussion Re: How big a cavity should double brick walls have? 2Jul 29, 2013 9:12 pm Accessible Carpentry & Cabinets accessiblecarpentry@gmail.com accessiblecarpentry.com.au https://www.facebook.com/pages/Accessible-Carpentry-Cabinets/583314911709039 Re: How big a cavity should double brick walls have? 4Jul 30, 2013 10:18 am As a comparison, my wall cavities are 70mm on a brick veneer Arfur Re: How big a cavity should double brick walls have? 5Jul 30, 2013 12:12 pm Thanks for the replies. It turns out there was a mistake on the plans, and it was specified as a 230mm wall, when it should have been 270mm. They are using 230mm x 110mm bricks I think, such that laying one crossways fits exactly across both layers. Looking down the between the layers you can only see one brick down before the mortar totally fills the gap. They are now suggesting that I can put insulation on the inside of the walls behind plasterboard instead. It sounds like I can reach the same R value this way (around 2.2), but I am concerned that this is not such a good option. Isn't it better to have the insulation inside a wall cavity? Also, the moisture issue Stewie D has raised sounds very bad. I thought double brick walls were always supposed to have a cavity, so I don't think I ever discussed wall thickness directly with the architect, and am now worried that I am going to have to foot the bill of several thousand dollars to start over on the walls. Re: How big a cavity should double brick walls have? 6Jul 30, 2013 11:30 pm Quote: As a comparison, my wall cavities are 70mm on a brick veneer. 70mm - gee that sounds wide. On brick veneer we used to allow 40mm - 50mm tops. Is that a South Australia thing or was there some structural reason ? Stewie Re: How big a cavity should double brick walls have? 8Jul 31, 2013 7:14 am In situations where water penetration is not a major issue such as in a garage a 230 wall is often used. An exterior wall to a habitable must have a cavity or as in the case of single skin concrete blocks a suitable waterproof membrane to the outer surface. On the face of it your Architect has a problem & I would expect them to rectify the issue & cover all costs. 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: How big a cavity should double brick walls have? 9Jul 31, 2013 7:19 am Quote: 70mm - gee that sounds wide. On brick veneer we used to allow 40mm - 50mm tops. Is that a South Australia thing or was there some structural reason ? Good question Stewie. I was surprised myself, when replacing my timber windows with aluminium I had to source wider reveal timber than normal (giving me a nice 155mm reveal) although in my days in the trade I have seen a few similar Arfur Re: How big a cavity should double brick walls have? 10Jul 31, 2013 8:51 am Quote: On the face of it your Architect has a problem & I would expect them to rectify the issue & cover all costs. As per Peters statement. The architect is a clown for not checking his plans before submitting them to the council or the builder and has made a mistake. The builder should have picked up on it as well. Very basic stuff. Quote: I was surprised myself, when replacing my timber windows with aluminium I had to source wider reveal timber than normal (giving me a nice 155mm reveal) although in my days in the trade I have seen a few similar Yeah I agree. We've demolished a few brick veneer walls for additions etc and come across a few discrepancies where the cavity at one end of a 5m wall was 10mm yet at the other end it was 75mm ????? Usually you'd suspect the timber framing is out of square somewhere but after checking it was pretty close to being spot on. I think the brickies had been trying to work their bricks into full or half sizes for window reveals etc. etc. Not good building practice. Stewie Hi All, I just wanted to close this topic out with an update. So we ended up agreeing to a number with the insurance company, and after an extensive amount of hand… 8 23401 Hey guys, what’s everyone opinion on James Hardie linea direct fix to frame? Would this be the most common method and anybody ever had any problems down the track? 0 5151 Firstly, if your house is still under builder's warranty (10 years in Victoria) you should have no need to crawl into roof space but let the builder handle it, unless you… 3 5640 |