The cost, hassle and mess of removing walls to add insulation has, for years, been the daunting reason why many people continue to live in uninstalled cold homes. Most DIY’ers take weeks, months or even years to insulate their walls the old fashioned way and it’s an expensive job for the professionals. Retrofit wall insulation systems can cost effectively complete your wall insulation project in about one to two days. There is no need to remove wall linings to upgrade your home! It is a hassle free and cost effective way to help give your old home that new home feel.

WHY SHOULD I INSULATE MY HOME?
Insulation will make your home warmer, drier, healthier and cost less to heat. Sunlight and heating systems pump heat energy into your home. The resulting temperature depends upon how much energy is pumped in and how much is lost. Imagine trying to fill a leaky bucket with water. To get more water in the bucket you could open the tap more, or you could find and repair the leaks. Insulation acts in the same way in your home and “plugs the heat loss holes”.

Heat leaks from your home by convection, conduction and radiation. Bulk insulation products act as a barrier to flowing heat allowing the heat to build up in your home. An increase in heat energy means higher temperatures and because less energy is being lost, your home is easier and cheaper to get up to a comfortable temperature. The increased temperatures also mean that your home will feel drier and the reduced relative humidity means that the development of mould is reduced or prevented.

HOW MUCH HEAT IS LOST THROUGH THE WALLS OF MY HOME?
A LOT – When you consider that an average home of 100 square meters has about 80 square metres of exterior walls, it’s no surprise that external walls lose a significant amount of heat. The large range of construction types and styles of home in New Zealand mean that it’s difficult to state the exact percentage of heat lost through walls, however it’s typically between 25% – 35%.

HOW IS RETROFIT WALL INSULATION INSTALLED?
The vast majority of homes in New Zealand are composed of vertical, horizontal and diagonal timber framing called studs, nogs/dwangs and bracing. Installers use a variety of techniques to find the cavities formed by these timbers, including high resolution thermal imaging, which some customers compare to an X ray of their walls. The insulation is blown into the wall cavities using small holes drilled either in the exterior cladding or the internal wall lining. The exterior cladding is left weather-tight with the aim to leave no sign that your walls have been insulated.

WHAT IF MY HOUSE DOESN’T HAVE BUILDING PAPER?
Certified wall insulation systems can be installed in wall structures with or without building paper. Dry mineral fibre insulation used by the leading retrofit wall insulation companies is highly resistant to absorbing or wicking liquid water so it does not require the additional protection from water that conventional insulation products require. Conventional insulation products are manufactured to be protected from water by building paper systems because they readily absorb liquid water.

CAN YOU INSULATE BRICK HOMES?
YES – the vast majority of brick homes are built as a masonry cladding over a conventional timber framing although some are a double brick construction. Some retrofit wall insulation companies are able to insulate masonry clad homes through small holes made in the “T” joint of the exterior brick cladding. Alternatively by customer request, the insulation can be installed via the internal lining, which works well if the plan is to redecorate.

Due to the drafty 150mm deep cavity found in most brick homes, they are one of the thermally least efficient wall structures in New Zealand. Customers with brick homes experience the greatest improvement in their property as the 150mm drafty cavity is converted to a wall structure containing insulation with a thermal rating of R – 4.2. New build walls typically contain insulation with a rating of R – 2.2.

Interior wall lining removed to show the 150mm cavity to the back face of the brick cladding.

HOW DO YOU KNOW THE WALL IS FULL?
The leading retrofit wall insulation companies use installation machinery that is designed to fill wall cavities in a similar way as a petrol pump turning off when your fuel tank is full. In addition, as part of a quality assurance process, your chosen company should fill a sample wall during each install. After a confirmation check that the sample wall is completely filled they can commence insulating the walls of your property.

As a final check, high resolution thermal imaging cameras are used to ensure that all areas of the wall have been correctly filled. Cold areas of walls that are not insulated are very clear to infrared technology and appear as a distinctive darker colour. Ensure to ask about this process when receiving your quote.

WILL MY INSULATION SETTLE OR SHRINK OVER TIME?
When installed by a leading retrofit wall insulation company, the dry mineral fibre insulation is installed under slight pressure and is packed into the wall cavity so it cannot slump, settle or shrink. The product used by Insulmax® has an E.U. Standard rating of S1 in relation to settling. This rating corresponds to settling measured below 1% or unmeasurable. The installed density of Insulmax® is over 50% denser than most conventional segmented fiberglass insulation products which contributes to it’s stability and high thermal and acoustic insulation properties.

IS THE RETROFIT WALL INSULATION METHOD CERTIFIED IN NEW ZEALAND?
The Insulmax® Retrofit Wall Insulation Method is CodeMark certified. CodeMark certification is administered by the New Zealand Government and is the highest form of product assurance in New Zealand. External auditing by AssureQuality ensures that high standards are always met. CodeMark is the highest form of certification in New Zealand and is an unchallengeable form of product assurance. Ensure you ask about CodeMark certification when receiving a quote.

Editors Note: This is a guest post written by Harley Turner from Insulmax