Chapter 22: Insulation and Vapor Barrier

1. Introduction

Ceiling and wall insulation is currently installed by an insulation subcontractor after the rough-ins have been done by electrical, plumbing, security, and HVAC. The ceilings are typically done using blown-in cellulose and the walls using fiberglass. However, we will assume that volunteers are installing it, and follow through with a comprehensive instruction chapter. It is an irritating job, but is easily done by volunteers. Make sure they are told to bring the proper clothing.

2. Safety Issues

Fiberglass particles can be particularly harmful. When handling insulation, wear sturdy, loose, long-sleeved clothing, gloves, goggles, face mask, and a hat. Do not allow anyone to work without a face mask especially.
If particles do get on your skin, do not scratch
Utility knives - keep your hands out of the path of the blade. Always retract blade when not in immediate use.
Shower as soon as possible

3. Prior tasks to have been completed before starting

• All rough-ins (electrical, plumbing, security, and HVAC) complete and inspected.
• All drywall nailers and blocking installed.
• All doors and windows installed

4. Recommended Staff/Crew Assignments

On the insulation installation day, the crew should consist of 2-3 crew leaders. It is suggested that there be approximately 15 volunteers recruited for this task. Each crew can work in a separate room, or possibly all crews can work on installing the attic insulation first.

6. Tools/Equipment list

Tools & Equipment Needed at Each Site:

• Twelve-Gauge Drop Cords (50'-100' as needed for power at site)
• Heavy-duty Power Strips
• Extension Ladder (16')
• Step Ladders (8')
• Step Ladders (6')
• Straight-edge or straight board to use as cutting edge

Tools Each Crew Leader Will Need:

• 30' Measuring Tape
• (2-3) Hammer staplers with extra staples

Tools Each Crew Member Will Need:

• Retractable Utility Knife with Extra Blades
• Measuring Tape (16' Min.)
• Safety Glasses
• Work Gloves
• Face Mask
• Long-sleeve shirt
• Hat

7. Material List

• Attic Insulation
• Wall Insulation
• 5/16” Staples
• Vapor Barrier (typically a roll of poly)

8. Quality Checkpoints

____ All ceiling and floor penetrations filled (by subcontractor typically)
____ Insulation loosely packed around windows and doors
____ Insulation installed correctly in attic and wall cavities. No gaps or compressed insulation.
____ Paper backing or poly sheets entirely covering exterior walls
____ Band joist cavities in basement loosely packed with insulation

9. Construction Drawings and Text

NOTE: The following drawings, diagrams, and text are to be used on the job site when a question arises as to methods and procedures associated with the task. The notes on the drawings have been geared toward use as a quick reference. If a more in-depth explanation is needed, please read the text description. But most importantly, consult your Habitat Site Supervisor and Construction Manager for advice as needed.

1. Installing Insulation:

General Note: Avoid permanently compressing insulation as this will reduce energy savings. Also avoid gaps in insulation for the same reason.

Insulating Ceiling & Floor Penetrations
All ceiling and floor penetrations must be insulated. These penetrations are typically found in the bottom plates and top plates where sub-contractors have installed plumbing or wiring. This job is the responsibility of the subcontractors, and should be pointed out to the Site Supervisor.

Insulating Around Windows and Doors
Insulate the perimeter of all windows and exterior doors between the frame and the walls. This can be done by pushing small pieces of insulation into the crevices with either a shim or a screwdriver. Do not pack the insulation tight. For very small gaps, caulk may be used.

Insulating Attic (Using fiberglass insulation)
Batts of insulation should be installed between the trusses. If the insulation comes with a paper vapor barrier, install the insulation so that the paper is facing the interior of the house. The paper will be wider than the insulation. This tab must be unfolded and stapled to the inside of each truss bottom chord. This should hold it in place until the drywall is hung. For irregular sized cavities, cut the batts ¾" wider than the space. To cut insulation, compress with a straight board and use a utility knife.

Insulating Attic (Using blown-in cellulose insulation)
When the attic insulation is blown in using cellulose insulation materials, the primary task to complete is the installation of cardboard baffles where the exterior walls meet the roof trusses. The baffles prevent the loose-fill insulation from flowing into the soffit area. Tack the cardboard baffles to the framing using roofing nails or staples.

When using raised heel trusses, a soffit dam should be created using a piece of fiberglass batt or rigid insulation to block the loose-fill insulation at the eave. In addition, a cardboard baffle should be installed along the truss rafters to create a channel for air flow from the soffit area to the ridge vent.

Insulating Exterior Walls
Fiberglass insulation usually comes in rolls that are pre-cut to 8' lengths. These batts may or may not have a paper facing. For irregular sized cavities, cut the batts ¾" wider than the space. To cut insulation, compress with a straight board and use a utility knife. Split batts by hand to fit on both sides of electrical wiring or pipes. It may be necessary to stuff scraps of insulation behind electrical boxes, wires, and pipes. Cut paper out neatly around electrical boxes.
If the insulation comes with a paper vapor barrier, install the insulation so that the paper is facing the interior of the house. The paper will be wider than the insulation. This tab must be unfolded and stapled to the inside of each stud.

Installing Poly Vapor Barrier on Walls
If the insulation does not come with a paper facing, it will be necessary to install a 4 to 6 mil. polyethylene film over all exterior walls. Measure the wall length and cut the poly from the roll several inches longer than this measurement. Then, unfold the poly and staple it to the top plate, studs and sill plate. If necessary, trim after stapling. Do not roll over wall intersections as it impedes drywall installation.

Insulating Behind Shower Unit
Insulation and a vapor barrier should have been installed behind the shower unit during framing. This applies only to shower units that are against outside walls.

Insulating Rim Board
In the basement between the joists at the rim board (exterior wall), insulation needs to be installed between the joists. Typically this is left-over fiberglass insulation cut to fit and held in place by friction (plastic vapor barrier material may be stapled over the insulation to hold it in place if necessary).

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  Page last updated Saturday, May 3, 2008 at 6:40:09 PM