Browse Forums General Discussion 1 Feb 06, 2012 1:24 pm I am at the early stage of owner-building a 2-story house in Melbourne, and have pretty much chosen EPS boards with render for external wall claddings. My challenges at the moment concern the pros & cons of: (1) cladding the timber frame not all the way up to the top plates; and (2) having a cavity between the frame & EPS boards. Allmost all of the installation manuals I've seen show the EPS board installed up above the soffit but stopped short about 200 - 400mm from the top plates. Why so? The gap seems to defeat the whole insulation purpose of using EPS cladding. One of the EPS manufacturer's technical service explained that the enclosing soffit and the roof would minimize the thermal exchange with the outside thru this gap. But why minimizing instead eliminating? Besides, if there are ventilation openings in the soffits and the roof, which will be in my case, this explanation is weak. Another poster has stated w/o further elaboration in this forum that a lack of a cavity between the EPS board and the frame would be bad for the house's and its occupants' health. My understanding is that the cavity has to do with moisture barrier. Unlike brick veneer, EPS' moisture permeability is very low. Again, unless this cavity space is enclosed reasonably air-tight, it would significantly, in my estimation, reduce the insulative efficiency of the EPS cladding. Perhaps it's a compromise. One cannot have a completely air-tight and inhabitable house. But there are plenty of other openings around the house. Do we really need this much additional exposure? The spacing of the studs looks pretty large especially for a load bearing wall. 3 11059 Oh no! I would use a can of expandable foam ( there are some that will take render) then cut it back and render over the top 1 4108 Thanks mate, is there a standard off the shelf type breathable product I can apply DIY? Thanks 2 8187 |