# Wall Top Plate Insulation



## joecaption (Nov 30, 2011)

http://www.energystar.gov/index.cfm?c=diy.diy_rafter_vents


----------



## Gary in WA (Mar 11, 2009)

In the above link Joe gave, if you down-load the rest, they used f.g. in garbage bags at open studs and under knee-walls, which is fine. Yet where it should also stop incoming air movement at the exterior wall line, they say just use an air-permeable f.g. batt, without the bag! F.g. should not touch the roof sheathing (conduction) at the baffle sides yet something should protect it at that soffit end from wind-washing (degrading the R-value). Night-sky radiation will wet the insulation in contact with the sheathing; http://www.buildingscience.com/documents/insights/bsi-049-confusion-about-diffusion

Best is to use homemade baffles of foamboard (stopping all air movement to your f.g.) pp.72; and add rigid f.b. stacked at the exterior wall line- pp.71 (Option 3); http://www.buildingscience.com/documents/published-articles/pa-crash-course-in-roof-venting

Another opinion on f.b. over wall at the slope junction; http://bct.eco.umass.edu/publications/by-title/reroofing-and-residing-to-save-energy/

Gary


----------



## Windows on Wash (Aug 30, 2011)

Just spray it with the same stuff you are seal the top plates with.

+1 to Joe and GBRs suggestions too.


----------

