Ceiling Insulation, Why It Matters Most and How to Top Yours Up
If your ceiling insulation is old, deteriorated, thin or missing altogether, it’s likely the main reason why you might not be able to keep your home warm. More heat escapes through your ceiling than through any other part of your house, after all, we all know that hot air rises. That makes ceiling insulation the first, and most important thing to get right for an energy efficient home. What’s more, It is also usually the cheapest place to win.
Why Your Ceiling Insulation Comes First
Heat rises. It gathers at the top of every room and then pushes out through the ceiling into the roof space above.
BRANZ puts roof heat loss at 30 to 35 percent in an uninsulated home. Windows, walls and floors each account for less. BRANZ says ceiling insulation should be the first priority when you retrofit an existing home.
That is why our Advisors look at the ceiling before anything else. It is the biggest single leak, and it is the easiest one to reach.
Summer Works the Same Way, in Reverse
Ceiling insulation is not only a winter product. On a hot day your roof sits in full sun for hours. The roof space underneath gets very hot, and that heat radiates down through the ceiling.
Bedrooms under a poorly insulated ceiling get stuffy by mid afternoon and stay warm long after dark.
BRANZ is clear that insulation works in both directions. It slows heat escaping in winter and slows it entering in summer. The same layer that keeps warmth in during July keeps heat out in January.
Are you eligible for a Warmer Kiwi Homes grant?
For households that qualify, a Warmer Kiwi Homes grant is the cheapest route to better ceiling insulation.
Warmer Kiwi Homes is run by EECA, the Energy Efficiency and Conservation Authority. It covers 50 to 90 percent of ceiling and underfloor insulation for eligible home owners. If you’d like to find out if you’re eligible we recommend booking an EECA Warmer Kiwi Homes Assessment with us.
To qualify you need to own and live in a home built before 2008. You also need a Community Services Card or SuperGold Combo card. Living in a low to middle income area also counts.
Criteria change, so ask us to check rather than assuming either way.
What to do if you’re not eligible for a Warmer Kiwi Homes grant
If you are not eligible for a grant that is not the end of the conversation. Most ceilings already have some insulation and a ceiling insulation top up might be all you need.
There are easy signs yours needs topping up. It sits below the level of your ceiling joists. It is thinner than 120 millimetres. You can see gaps in the coverage.
Topping up costs less than starting from scratch, because you keep and reuse the layer you already paid for. If you’re a home owner, you should also ask your bank about energy efficiency low interest loans as they are readily available from most major banks.
Why Blown Insulation Suits a Top-Up
Blown insulation goes in over the top of what is already there. Nothing gets ripped out, and nobody disturbs your ceilings from below.
It also goes where batts cannot. Installers blow it around trusses, wires, pipes and the awkward corners near the eaves. Old batts almost always leave gaps in those places.
Those gaps matter more than people expect. BRANZ found insulation loses roughly 3 percent of its R-value for every millimetre of gap around the edge. A finger-width gap can cut performance almost in half.
Then there is the R-value itself. R-value measures how well a layer resists heat passing through it, so a higher number performs better. Adding a new layer over an old one lifts the total. It will not always double it, because a heavy top layer can compress the one underneath. Ask your installer about that.
What We Recommend, and Who Fits It
We assess and recommend. We do not sell or install, so our advice is not tied to a product.
For a ceiling top-up we point people to Safe-R, whose blown ceiling insulation is made for exactly this job. Blow Insulation are the specialists who fit it, and they are part of the Healthy Home Team group.
Our article on heat transfer systems covers the regional companies who handle the heating side.
Talk to the Healthy Home Team About a Warmer Home
At Healthy Home Team we help assess the state of your ceiling and tell you what it actually needs. Sometimes we’ll recommend a full insulation replacement, but more often than not it is an insulation top-up.
Book an appointment with your local Healthy Home Team Advisor today, and let’s start a conversation about creating a healthier, more energy-efficient home.