You would be right to say ceiling level Roof Insulation is one of the weakest areas causing Room Heat loss in a building. In a house with no roof insulation this may be as high as approximately 30% of the total building losses.
Roof Insulations
Roof Insulation may be divided for simplicity as:
• Ceiling Level Roof Insulation
• Rafter Level Attic Insulation
Ways You Lose Heat through the Roof
Lack of insulation, poor insulation or damaged insulation all contribute to the waste of Thermal Energy through a roof. If you are considering an energy saving upgrade this is
the first place you have to check.
Interestingly some of the existing homes may be already fitted with roof insulation. You may be confident that this is adequate for the purpose as you installed correct thickness in the beginning itself.
But what you may not realize is that:
• The insulation settles over the time and the current thickness may be less.
• The spaces between the insulation fibers are essential for its insulation property. Once the fibers settle or get crushed the insulation quality is decreased.
• Moisture and pests damage insulation and some places may be even totally devoid of any insulation material without your knowledge.
• The radiant heat loss (and vapor) barrier may be damaged over the years
How do you gauge the Insulation Property of Materials?
The insulation property of a material is gauged by it’s “U” factor which is a measure of the quantity of heat that will be conducted through that particular material The lower the “U” factor the lesser will be the Heat Lost (ie. transmitted) through it and in turn the warmer your home will be.
Home Energy Saving Scheme stipulates achieving of a U value of 0.13 W/mK or less in order to qualify for the Ceiling Level or Attic home Insulation Grant.
How much will an upgrading save you?
If you consider an average house of approximately 150 m2 having a roof insulation of 100 mm thick resulting in annual energy bill of approximately Euro1600 one can expect a saving of approximately Euro 250 per annum if the insulation is increased by a further 200 mm. in order to achieve the HES scheme stipulated thickness of 300 mm. (This will earn credit towards qualifying your installation for the roof insulation grant of the SEI).The total capital cost for such an installation would be in the region of Euro 700 to Euro 1000 without the benefits of the grant.
A simple technique for Roof Insulation
If your house consists of a Pitched Roof and an Attic Space, a simple way to fix the insulation is to lay a quilt of insulation material such as Mineral Fiber, Rock Wool, Fiber Glass Wool, Hemp, Sheep Wool etc.(among several others) horizontally over the ceiling
It is recommended that the insulation quilt is laid in two layers and crosswise to each other to achieve the best performance.
If your roof is flat the insulation can be fitted to the roof with Insulation Slabs and Plaster Board.
More Tips
The insulation which will fit between joists should be cut true to fit tightly to prevent heat loss through the gaps. It is important to fit the home insulation to cover the joists right over as heat is lost through these as well. It is always good to avoid use of attic space as a storage area as this might damage the insulation. When laying the insulation ventilation grilles to attic should not be obstructed by your new insulation. The storage water tanks, hot water cylinders and plumbing should be thoroughly insulated to prevent freezing (though these may not have been insulated before).Ensuring a catwalk (walkway) to reach the water tanks and other areas needing maintenance is installed so that the roof insulation may not be damaged.
Any money spent on upgrading the Roof Insulation does not necessary cost you the earth especially if you take in to account the life cycle cost and the savings over the years. The typical example sighted above shows what one might expect as monetary savings.
An added benefit would be the tons of savings on CO2 emissions that will help your environment
many years to come.
Thanks the Techstore Team
