House Insulation: All You Need to Know

Insulation is all around us and helps to keep our buildings warm in the winter and cool in the summer. It is incredibly important when it comes to reducing your home’s energy costs and consumption. By upgrading your home’s insulation you could make significant savings on your heating bills, as well as your household’s carbon footprint.

One of the most effective ways is PIR Insulation, which can be used in a wide variety of applications, including walls, roofs and floors, to meet the required U-values for new buildings as well as when retrofitting existing buildings.

Three main types of insulation are:

• Roof/Attic insulation
• Wall insulation:
• Cavity wall insulation
• External wall insulation
• Internal wall insulation
• Floor insulation

Cavity wall insulation is by far one of the most cost-effective ways to insulate your house. Insulating them is simple and consists of injecting insulation material directly into the cavity. Nowadays, using spray foam to insulate a cavity wall is also becoming common, but they tend to be more expensive.

Commonly-used insulation materials in Ireland are:

• PUR & PIR
• Fibreglass
• Insulation Foam
• Sheep’s wool
• Rockwool
• Cellulose

How does cavity wall insulation work?

A hole is drilled into the walls to be filled and the insulation material is injected. Afterwards, the drill holes are filled in and matched as closely to the surrounding wall as possible, although you may still need to touch up the walls at the injection site.

External wall insulation

External wall insulation may be some of the most expensive renovations to do. you will need to check with the relevant local council authority whether any planning permission will be needed for adding the external insulation. 

For solid block or concrete walls with no cavity, external wall insulation is generally the preferred option. It can also be used in addition to cavity wall insulation to further improve the performance of your external walls. External wall insulation involves wrapping a layer of rigid insulation around your home, fixing it to the walls, embedding mesh in it to provide strength, and covering it in a render to provide weather resistance.

Internal wall insulation

Internal wall insulation, also known as insulation with plasterboard, is a less expensive way to insulate external walls and consists of fixing insulation material to the inside of the house’s exterior walls, and then finishing it off with plasterboard.

Internal wall insulation might be recommended for your home because it has solid or cavity block walls, and external insulation is either not possible (i.e. for some protected structures) or is not considered the best solution.

Internal insulation (sometimes referred to as ‘drylining’) usually involves fixing insulation boards to the inside of the external walls and covering them with a vapour control layer, plasterboard, skim and new painting. As the boards are applied to the inner side of the walls, there will be some loss of space in the rooms.

Pump the cavity with bead insulation- If your home has cavity walls which are not insulated, or only partially insulated, then cavity wall insulation is an easy, cost effective first step to reduce heat loss. If your home has a cavity wall, insulation is pumped into the cavity. A series of small holes are drilled in the wall, at regular intervals, on the outside. The insulation is then pumped into the cavity through these holes, and the holes are filled in so that they match the rest of the wall.

Floor Insulation

Floor insulation is to protect the cool ground air from entering the home. Most modern homes have spray foam insulation below the concrete base to reduce heat loss, usually Polystyrene.

If you have an older home, the simplest way to overcome heat loss through the ground floor is to lay carpet with foam backing or a foam underlay.

Insulation can be inserted underneath your floorboards between the joists, but this will require pulling up your floors.

Rigid insulation, such as rigid foam insulation, can also be laid on top of the under-floor concrete slab.

Roof/ Attic Insulation

Around 25 per cent of heat is lost through the roof of your home. Building regulations stipulate that to meet today's standards your attic should have a minimum of 12 inches (300mm) of insulation.

By simply insulating your loft, you will not only be making your home more energy efficient, saving around €130 per year on energy bills, you will also make your home warmer and more comfortable to live in as well as doing your bit in reducing green house gases. You can also provide additional insulation to the roof between and roof joists.

Is It for Me?

Learn more about technique information and latest Insulation Regulations & Guild lines on our "Go Green & Build" Section.

Contact one of our qualified advisors to survey your property and let you know what simple measures your property requires to meet the current building regulations.

Check out our Grants Section to find out if you are eligible for various government Grants and Supports.