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The Afternoon Show
The Afternoon ShowRTÉ One, Weekdays, 4.00pm

The House Doctor

Tuesday, 17 November 2009

Tom Brennan will show us common insulation problems and solutions

Autumn is here, winter is around the corner and insulation problems are felt more at this time of the year, leading to illness or costly insurance claims. But help is at hand!

Dr Thomas Brennan -from

Has devoted the greater part of his life to developing and researching methods of non-destructive treatment and protection of historic buildings and family homes. He has pioneered several non intrusive exploratory techniques which has greatly reduced damage and costs normally associated with general inspection methods. He is involved in many European research projects and has lectured in Trinity, UCC, and RICS etc. With a doctorate in conservation, he has won the Conservation Award of Excellence and numerous awards for his work as on the Old County Hospital Portlaoise, Farmleigh House and 25 Eustace Street, Dublin.
Up to 30-35% of heat produced in the home is lost through an un-insulated attic.

Attic insulation
. Ceiling level insulation
. Rafter level insulation

Benefits of Roof Insulation:
. Reduction in heating bills
. Increased comfort levels
. Low capital cost
. Short payback periods
. Reduction in Greenhouse Gas emissions

The Benefits of Wall Insulation:

. Reduction in heating bills
. Increased comfort levels
If your home is built using solid wall or hollow block construction methods, cavity fill insulation is not an option. Internal insulation (sometimes referred to as 'dry-lining') involves fixing insulation to the inner surfaces of your external walls. This usually involves fixing an insulation board to the walls and covering it with a vapour barrier layer and plasterboard. Reduction in Greenhouse Gas emissions

Cavity wall Insulation:
A cavity wall consists of two rows of brick or concrete block with a cavity or space between them. Injection of insulating product from the outside is the best method for insulating this type of wall. This type of insulation must be done very carefully to ensure that the cavity is fully filled and that there is no thermal bridging. This can be difficult and therefore internal or external insulation can be the preferred options.

External Insulation:
External insulation involves fixing insulating materials such as mineral wool or expanded polystyrene slabs to the outer surface of the wall. The insulation is then covered with a special render to provide weather resistance. A steel or fibreglass mesh is embedded in this render to provide strength and impact resistance.

Heat flows naturally from a warmer to a cooler space. In the winter, this heat flow moves directly from all heated living spaces to adjacent unheated spaces, or to the outdoors; or indirectly through interior ceilings, walls, and floors - wherever there is a difference in temperature. To maintain comfort, the heat lost in winter must be replaced by your heating system. Insulating ceilings, walls, and floors decreases this heat flow by providing an effective resistance to the flow of heat.
The effectiveness of an insulated wall or ceiling also depends on how and where the insulation is installed. For example, insulation which is compressed will have reduced effectiveness. Similarly the effectiveness of insulation in wall or ceilings can be diminished because some heat flows around the insulation through the studs and joists. With careful design, this short-circuiting can be reduced.

To put it simply, U-Value is the measure of the rate at which heat is lost through a material. As it is a measure of heat loss, the lower the U-Value the better. So for example, one square meter of a standard double glazed window will transmit about 2.5 watts of energy for each degree difference either side of the window (denoted by the unit W/m2K) whereas a low-emissivity window will do better at about 1.8 W/m2K.

Good workmanship and attention to detailing are most important when insulating a building, to avoid thermal bridging and other related problems, and could have greater impact on overall heat loss than simply increasing the thickness of insulation.
Grants are fixed for each type of measure as indicated in the table below. Grant approval must be in place before any purchase of materials or commencement of measures undertaken. Grants are paid after the measures are completed and the contractor has been paid by the homeowner. In the instance where the cost of the work (vat inclusive) is less than the fixed grant amount, the actual cost will be reimbursed. You are entitled to claim all of the grants!!

1. Roof Roof Insulation €250
2. Wall Cavity wall insulation €400
3. Internal Wall Dry-Lining €2,500
4. External wall insulation €4,000
5. Heating Controls High Efficiency Gas or Oil fired Boiler with Heating Controls Upgrade €700
Heating Controls Upgrade €500
7. BER Assessment A Before works and an Afterworks BER assessment €200

Grants from Sustainable Energy Ireland -
Attic Insulation
. Rolled Fibre Glass
. Blown Loft Insulation
Cavity Wall Insulation
. The wall cavity is filled with Bonded Beads. A hole is drilled and beads are blown into the cavity.
External Wall Insulation
. Cladding the external walls with a composite build of seamless rigid insulation to the entire outside of the building.
. This is then coated with insulation with a reinforced protective base coat before applying a finish coat which is usually a coloured acrylic render.
Internal Wall Insulation
. Insulated internally - usually referred to as internal dry-lining.

Depending on the type and style of building there are many options available to insulate your home.

If you have a solid brick or block building or stone building, insulation can be achieved in the following manner.

If the areas internally are of high decorative value and cannot be altered - insulation can be placed on the exterior of the building. The unfortunate point about external insulation is that you lose some of the aesthetics of the external wall. It is always best, if possible, to insulate from the inside. Many houses built in the 1920-30's and upwards are quite suitable for this as they had a very plain external finishes to the exterior.

There are a number of systems available on the market, from solid board type systems such as bonded aeroboard to rockwool and rigid insulation slabs used in conjunction with plastering systems all give excellent insulation value.

The systems available for internal insulation are wide and varied. We can go back to the original dry lining system and in between that you put batons on the wall and between the batons insulation materials are fixed. The products range from Rockwool or Glass Fibre which is fibre glass wool - (new fibre glass wool available without the risk of skin irritation to those DIY experts who may be installing the material).
Kingspan manufacture a high density board which is an excellent insulation system.

Thee main products are Kingspan, Hightherm and Quinnterm - These materials are buttoned directly onto the wall using a plastic plug system. This eliminates the necessity for timber batons and this is also an excellent means of insulation.

In the past attics were insulated with 4" of insulation which was the accepted grade now it is the norm is to use 8-12" of insulation as the best means of insulating attic space.

It is also important to bear in mind that there are some grants available for the various systems. E.g. Attic insulation there are grants available of c.€250.00. For walls anything from €400 - €4,000 can be achieved. For heating control systems there are grants available of up to €500.00. If you incorporate a new boiler into you heating system there is a grant for the boiler up to €700.00. for more details.

To have a BER Assessment carried out where a trained assessor uses a thermographic camera to take thermal photographs of your building showing where heat is being lost in the building.
This camera can highlight the cold spots in the building where heat loss is occurring. It is also a very good tool for detecting damp in a building. Grants of up to €200.00 are available.

There are other systems of insulation whereby the material is pumped into the cavity and this is very popular if you have a cavity wall. Even though the cavity wall is already built with a rigid system there is normally a 2" airflow gap. This gap causes a cold airflow and cools the building down. This can be filled with various types of bonded bead and this can be demonstrated using a model in the studio and physically happening on site.

Attic insulations. This can be done with materials ranging from papier-mâché, rockwool, fibreglass wool, loose fibre rock wool which can be blown around and this covers every crack and crevice. This system allows air to flow.

Rigid systems can also be installed in the attic. This is where you want a want a warm attic where you can run with the slope of the roof and insulated between the rafters with high density board from the various 3 big manufacturers, Kingspan, Quinntherm and Hightherm. This product renders the attic as a warm place. If you insulate the ceiling the attic becomes a cold place so it is important to bear in mind that you insulate all your water systems i.e. water tank, expansion tank and any plumbing systems that are in the attic. The attic has the same temperature as outside so this may lead to burst pipes in the winter. These are simple things that can be demonstrated.