Search

A safe and healthy roof is a crucial part of each building. When one or more of the following roof problems occur, we know that the safety of your roof is at risk:

  • A leaking roof
  • Deteriorating roofing materials
  • The roofing materials are moving or shifting to an accepted degree, or the shape of material is changing.
  • The roof has an unsightly appearance.

The causes of roofing and flashing problems usually spring from design, from the materials selected by the builder or architect, and finally from the way the contractor applied the roofing and flashing.

Moisture and Roofs

Contemporary architects and building engineers recognize that their systems are vulnerable to moisture due to 3 sources:

  1. Rain penetration
  2. Entry of water vapor
  3. Ice damming

To avoid these dangerous situations, certain building science principles behind the problems of moisture and roofing should be understood.

Roof problems: Ice damming on shingle roof

Rain Penetration

Roofs leak when water finds an opening and sufficient force is applied to drive the water inwards. To eliminate rain penetration the roofer must either close the openings or neutralize the driving force. A sloped bitumen shingle roof seldomly leaks because gravity offsets the forces acting to move the water inward. Overlapping the shingles limits the direct entry of rain drops by impingement.

Gravity acts to move water outward down the roof slope. The greater the vertical height of the shingle lap, the greater the gravitational force. Leakage occurs when the roof is not sloped enough to let the force of gravity resist the wind force driving the rain through the openings. Generally, the only way to control water penetration on low slope roofs is by applying a continuous waterproofing membrane.

Roof problems: Rain on a shingle roof

IKO offers a few solutions for such critically low-pitched roofs:

 

1. Self-adhesive Cambridge Xtreme shingles can already be installed under certain conditions from a pitch of 9,5 degrees.

 

2. The IKO Thermo System concept can even be installed from 4 degrees, thanks to the Armourbase Thermo AD underlayment. This roll can be heated with a torch, which makes it possible to install the shingles without nailing.

 

!!! Attention: In case of low-pitched roofs, avoid ponding water. Roof leaks will occur, and damage will be considerable!

Water Vapor Penetration

Condensation on the inside surface of roofing materials is caused by water vapor moving through the ceiling system. It condenses on roof materials if their temperature is lower than the dew point. This happens during winter when the inside air has a higher moisture content and vapor pressure than the outside air. Humidifying the house can make the condensation worse.

Moisture severely damages building materials, causing them to deform and deteriorate. It can cause curling, cupping, and shrinkage on roof surfaces with bitumen shingles, corrosion on metal flashings and rotting of wooden roof structures. Builders should use a roof system designed to prevent the entry of water vapor by both diffusion and air leakage, or one that can remove the vapor by ventilation.

<<< Condensation forming in attic space.

 

Roof problems: Explanation vapor or condensation of roofing

Proper ventilation is the key factor in how to avoid moisture from the attic. An excellent ridge ventilation is IKO Armourvent Multi. IKO Armourvent Multi and Multi Plus are ventilation systems that provide you with a fabulous roof without visible appliances. The unique design consists of a thin but ultra-strong profile ensuring a smooth, straight, and virtually invisible roofline.

IKO ventilation on your roof offers quite some benefits:

  • Extend the life of your roof and of your shingles
  • Increase your living comfort
  • Regulate the moisture in your roof
  • Allow excess heat and water vapor to escape from the roof
  • Allow air to circulate between insulation and roof deck
  • Prevent humidity from damaging the roof construction
  • Cool down the roof in hot weather conditions
  • Prevents ice dams after snow
Armourvent Multi ventilation on roof

If we look from inside the house structure, vapor barriers and air barriers prevent water vapor from moving to the roof system. Some of these techniques include:

  • Installing a vapor barrier of 0.15 mm polyethylene on the warm side of the insulation in the ceiling
  • Cutting air leakage to the attic space by sealing holes leading to and from the house below