Red Bank, NJ Kneewall: From Poorly Insulated to Efficiently Insulated
Challenge
In Red Bank, NJ, we’re examining a kneewall where the floor of the kneewall space also serves as the ceiling for the room below. The exposed fiberglass insulation doesn’t effectively block air flow, leaving it inadequate for air sealing and insulation. As a result, the floor of the upper level, the ceiling of the lower level, and the kneewall itself remain cold in winter and hot from radiant roof heat in summer. Additionally, the kneewall space is unsuitable for storage due to temperature fluctuations and dust.
Solution
Blocks of Foamax insulation are placed between the ceiling joist bays. The gaps outside the blocks are sealed with sprayed foam or Foamax boards. Foamax insulation is also installed under the rafters up to the kneewall and sealed at the top with foam sealant. This setup prevents inside air from escaping through the kneewall spaces and stops outside air from entering, ensuring the kneewalls are well insulated. As a result, the homeowner now enjoys a warmer upstairs room in winter and a cooler one in hot weather, with fewer drafts, less dust, a properly insulated storage area, and a more comfortable, energy-efficient home.
Project Summary
Products Used: Foamax, Spray Foam & ZypFoam Sealant