Is Moisture Infiltrating Your Roof?

May 10, 2013

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Moisture can enter into a roofing system many different ways. In addition to water entry due to roof membrane leaks, moisture can enter a roofing system due to condensation from internal humidity, infiltration through building walls, water entry through equipment housings and latent moisture entrapped beneath the roof system. Note: The inspection for moisture infiltration requires professional roofing experience.








1. Building Walls & Parapets
Many types of wall construction, especially masonry and stucco, can allow moisture infiltration due to porosity and cracking. Particular attention should be paid to metal flashings associated with walls, including wall copings, counter-flashings, and termination bars.
2. Large Rooftop Units
Frequently the metal housings around these units may allow water entry.
3. Skylights
Skylight glazing beads and metal trim flashings typically require periodic maintenance.









1. "Soft" Roof Insulation
If the roof insulation appears to be "soft" under foot, it may have absorbed excessive moisture.
2. Cracking, Spalling or Discoloration Of Walls
The deterioration may be an indication of moisture entry.
3. Loose Metal Wall Flashings
Look for any discontinuities in the firm, uniform compression between metal flashings and the wall surface.
4. Covered "Weep Holes"
Look for masonry weep holes that have become clogged or were accidentally covered over by the roof flashings.
5. Missing Or Broken Weather Seals On Equipment Housings
Frequent maintenance of rooftop equipment may allow weather seals and sheet metal joints to loose water tightness.
6. Cracked or Sunken Caulking
Almost all joints in metal flashings are sealed with an application of sealant or caulking. Any cracking or other discontinuity is a potential source of water entry.









1. Replace Wet Roof Insulation. A licensed roofing contractor should perform this work.
2. Re-Attach and Re-Caulk Metal Components. Maintenance of metal flashings and caulking
Joints typically can be performed either by a roofing contractor or trained maintenance
3.Repair Deteriorated Walls. Repair of walls can be performed by a variety of trades. Be sure
to select a recognized professional.









1. Roof Moisture Survey: If a new roof will be installed over an existing roof, or whenever moisture is suspected to be entrapped within a roof deck, a roof moisture survey should be conducted by a recognized professional, and the findings of the survey should be used by the roof designer to select the most appropriate roofing system.

2. Rooftop Equipment Maintenance Standards: A roof access log should be maintained in order to review and monitor the maintenance of rooftop equipment.

All roofs require periodic inspection and maintenance in order to perform as designed and to provide a long and effective service life. Periodic inspection and maintenance is also typically required by roofing system manufacturers to keep roofing warranties in full force and effect. Although all building owners should establish a periodic roof inspection program, inspection and maintenance of any roof should be undertaken only by qualified persons who are familiar with safe roofing practices, including all applicable occupational, health and safety regulations relating to the
roofing and construction industries.

Modern roofing systems contain a wide variety of components and installation techniques. All roof inspections should be conducted by a licensed roofing contractor or similar roofing professional.
Typically, two inspections should be conducted each year, one in the spring and one in the late fall. If the roof is warranted, at least one roof inspection each year should be conducted by the licensed
contractor who originally installed the roof.