Bonus Room Knee wall Insulation
78bluestreak
| Posted in Energy, Heating & Insulation on
FHB – I had an ice dam last winter over the garage bay. three exterior walls (all insulated) with soffit venting and a roof can in the attic space. i hope to avoid a repeat of the event this winter. the ceiling of the bay is insulated and the soffits are moving air. my question is should I install baffles to direct the air flow along the ceiling and then add more insulation. looking for solutions. this is not an easy space to access but worth the headaches of worries over ice damming.
Replies
if you havent yet, locate all light penetrations and foam them, seal off as many holes you can.
if you have done this then increasing your attic ventilation and adding insulation would be way to go.
you have to much heat getting in the attic (through leaks mostly) and not enough ventilation to keep your roof deck from melting the ice on the top side.
The trick is to maintain airflow from the soffits, through the kneewall area, into the "attic" area, and out the rooftop vents. It's fairly common for airflow to become blocked by insulation or framing near the top of the kneewall and upset the applecart. As to the kneewall space itself you can either install baffles on the rafters and make it part of "conditioned" space, or insulate/seal the kneewall itself and make the space behind part of the "attic".