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
- 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.