Underfloor insulation is one of the most overlooked upgrades in New Zealand homes. People repaint, renovate the kitchen or buy a better heater, then walk across a cold floor every winter morning. If your house has a suspended timber floor, the space under it is often where the cold and the damp are coming from.
What underfloor insulation is
Underfloor insulation goes beneath a suspended timber floor, between the joists, so the floor sits above a layer of insulation instead of open air. It is common in older Kiwi homes, including villas and bungalows, that were built without any.
For retrofit underfloor work we install Mammoth. The aim is simple:
- A floor that feels warmer underfoot.
- Fewer draughts rising through the boards.
- A drier, more comfortable home.
Why it matters
Warmer, more comfortable rooms
The difference is easy to feel. A bare timber floor over open air is cold, and it pulls warmth out of the room above it. With underfloor insulation, rooms feel less draughty and more settled.
Less damp and condensation
Cold floors and damp subfloor air contribute to musty smells, condensation and mould. Insulation on its own is only part of the answer. On damp ground, a ground moisture barrier that stops moisture rising into the space under the house is just as important, so the two often go together.
A healthier home
A drier, warmer home is more pleasant to live in, especially for children and older people. A warm, dry house is simply a better place to be.
Heating that does less work
When less warmth is escaping through the floor, your heater has less to make up. How much that matters depends on your house and how you live in it, so we will not put a figure on it.
For landlords
If you rent out a property, we can help with the insulation your rental needs and arrange a Healthy Homes assessment for you.
What it costs
As a guide, underfloor insulation for a 100m² home runs from $2,200 to $2,500. Your quote depends on access and materials. A low, tight crawl space is harder work than an open subfloor. Our quotes are clear and detailed, with no hidden fees.
For a 100m² home, the job typically takes about a day.
Choosing an installer
Underfloor work happens in tight, awkward spaces, and gaps or sagging insulation are easy to leave behind. When you compare installers, ask:
- Are they licensed and insured?
- Is the quote written, clear and detailed, with nothing hidden?
- Will they assess the subfloor for moisture as well as insulation?
- What do they do if access is difficult?
We are licensed and insured, with a team of four, and we work across the Bay of Plenty, Coromandel and Hauraki and Gisborne and the East Coast. Coastal homes in particular benefit from a good look at the subfloor. See our underfloor insulation page for how we work.
Where to start
If you are not sure whether your floor needs attention, start from the top. Ceiling insulation is usually the first upgrade, and the floor is a close second. If you live near the water, you may also like our post on the role of insulation in coastal homes.
Get a free quote
Ready to insulate your floors? Request a free, no-obligation quote. We aim to call you back within 48 hours, or you can phone us on 027 482 0333.