[GSBN] windscreen

[John Straube]

Well Jim that is darn useful stuff!   have you done a paper or something on this?  Would be great to have this info to spread around.



On 2011-01-22, at 5:25 AM, Jim Carfrae wrote:

> As part of my research into the moisture performance of SB in a Temperate Maritime (Damp) Climate , I've monitored two structures where a direct comparison can be made between a plain lime rendered section of wall adjacent to a section of the same wall protected by a ventilated timber rainscreen. 
> (Plain lime wall = 3 x 12mm coats. Rainscreen = 1 x 12mmm scratch coat, 25mm vented void, permeable membrane, 25 mm vented void, vertical timber boarding with 5mm gaps) 
> In each case the average moisture content of the straw just behind the render was between 3% and 4% lower (typically 17% behind plain render, 13% behind rainscreen)
> This is an apreciable difference, especially as this was not a particularly exposed site. If there was significant driving rain I would expect the difference to be higher.
> 
> To reinforce what John Straube said - It has to be vented top and bottom.
> 
> Jim (moist) Carfrae
> 

Dr John Straube, P.Eng.
Associate Professor
University of Waterloo
Dept of Civil Eng. & School of Architecture
www.buildingscience.com