Attic Access

Desired Outcome:

Attic access door properly sealed and insulated

SWS Detail: 3.0103.1 Intentional Attic Openings

Author: Jake

Before

Panel not insulated, No dam existing

After

Panel insulated, dam installed

Steps

  1. Horizontal access on thermal boundary

  • Includes steps 1a. - 1e.


1a. Secure panel

  • Secure panel by adhering a weight such as a brick to interior ceiling accesses, or a latch.


1b. Insulate panel

  • Insulate panel to same R-value as adjoining insulated assembly using rigid foam board & ignition barrier or fiberglass batts and attach with construction adhesive.


1c. Repair/Install casing

  • Repair or install casing to allow for installation of gasket.


1d. Airseal attic panel

  • Install foam tape or weatherstripping on panel and ensure air tight seal.



1e. Build a insulation dam

  • Build an insulation dam to allow for maximum attic insulation R-value that extends 2" above height of insulation using rigid materials like plywood so that the dam supports the weight of a person entering the attic.

  • Use Fiberglass batts to build insulation dam when access opening is limited.


2. Vertical access on thermal boundary

  • Follow steps 2a. -2 e.


2a. Secure panel

  • Secure panel with latches, fasteners, and or hinges.


2b. Insulate panel

  • Insulate panel to maximum practical R-value using rigid foam board & ignition barrier or fiberglass batts and attach with construction adhesive.


2c. Repair/Install jam

  • Repair or install jam to allow for installation of continuous gasket around the edges of the panel.


2d. Airseal access door

  • Install foam tape or weatherstripping on door or jam to ensure air tight seal.


2e. Insulation dam

  • Build an insulation dam to allow for maximum attic insulation R-value that extends 2" above height of insulation using rigid materials like plywood so that the dam supports the weight of a person entering the attic.

  • Use Fiberglass batts to build insulation dam when access opening is limited.


3. Access not on thermal boundary

  • Follow step 3a. Air sealing and insulation is not necessary.


3a. Latch access panel

  • Install latch to secure Access panel in garages and on vertical access panels.


4. Access with attic ladder on thermal boundary

  • Follow Steps 4a. - 4d.


4a. Build a insulation dam

  • Dam shall be made of rigid material and high enough that the insulation will be inside the walls of the dam and above the stairs. (see image)


4b. Air seal insulation dam

  • Seal all joints with mastic or one part foam.

4c. Build & insulate panel

  • Insulate panel with fiberglass batts.


4d. Airseal between top of dam and panel

  • Install foam tape on panel, be sure to wipe panel before installing foam tape to ensure proper adhesion.


5. Worst Case Draft

  • Conduct a Worst Case Draft Test to verify Category I, II and III appliances are venting safely before leaving home for the day.

  • Testing shall be recorded using the Utah WAP Worst Case Draft Test from.