Vanilla 1.0.3 is a product of Lussumo. More Information: Documentation, Community Support.
31 to 60 of 76
Posted By: adwindrumLots of theory, however has anyone got the perfect construction?
Posted By: Viking HouseThere has never been a documented case of decay in a wall due to moisture movement through a wall by diffusion alone!
Posted By: fostertomAnything on EPS, plywood? Along with OSB, I'd have thought both those wd be wideish-range figures, like several of those above. Strange that cem (?) render is so different from conc.
Posted By: TimberWhy is it hard to apply the 5:1 rule in existing buildings? Un-insulated buildings kind of fall outside of that rule, as the heat loss through the structure reduces the risk of condensation. Most types of building with insulation in them generally follow the 5:1 rule or get close to it.We know that there are potential risks with IWI on existing masonry walls if you put lots of insulation in (although this is another area where concrete proof of this is difficult tofind!).
Posted By: rhamduPosted By: Viking HouseThere has never been a documented case of decay in a wall due to moisture movement through a wall by diffusion alone!Can you say that again louder?
Posted By: Mike GeorgeEPS around 100,000
Posted By: Mike Georgecement. Noteable that it is the *same* as Lime.Concrete has a higher value as it necessarily contains a higher proportion of cement (to sand) and also chippins
Posted By: Mike GeorgeI was also surprised by the cement. Noteable that it is the *same* as Lime.
Posted By: djhHi Mike, Does the BS give a source for the numbers? Presumably it is quoting some experimental measurement somebody did somewhere at some point.
Posted By: Mike GeorgeWhy do you think the cement content makes no/little difference?
Posted By: Mike Georgemain school of thought ... that rich cement renders = impervious renders
Posted By: Mike GeorgeExpanded polystyrene 60Extruded polystyrene 150PUR 60Mineral wool 1Phenolic 50Perlite 5Wood wool 5Poly beads 2
Posted By: fostertomPosted By: Mike Georgemain school of thought ... that rich cement renders = impervious rendersDoesn't that mean impermeable to liquid water, which can be unrelated to water vapour permeability?
Posted By: SteamyTeaYes there are variables, but to a certain extent changing the flow rate can account for that so you can get an intuitive feel for the problem.The main point though when modelling this is to use the output from one as the input to another, if you want to include flows in the other direction, multiply that side of it by -1 and then add it to the input of that element. You can imagine it as pulling and replacing the plug.
Posted By: Mike GeorgeEither way though, the arguments against cement in this regard seem unfounded, as it will allow vapour passage as easily as lime.
© Green Building Press