Floor Insulation in Ireland: A Practical Guide for Irish Homes
Ground floors are one of the most overlooked parts of an Irish home. Here is how to tell what kind of floor you have, how each type is insulated, and what to think about before any work begins.
When people think about insulating their home, the attic and walls usually come to mind first. The floor is often forgotten, even though every ground-floor room sits on top of it.
Ireland has a very mixed housing stock. Period terraces, 1930s and 1950s semi-detached houses, bungalows and newer builds all have different floors, and a solution that suits one can be completely wrong for another.
That is why good floor insulation in Ireland starts with understanding the floor you actually have, rather than picking a product first.
Most Irish homes have either a suspended timber floor, with boards over a ventilated space, or a solid concrete floor laid on the ground. The way each one is insulated is very different, so this is where every floor insulation job begins.
Why Floor Insulation Matters in Irish Homes
Our climate is mild but damp, and the heating season is long. A cold, draughty ground floor can make rooms feel uncomfortable for much of the year, even when the heating is on.
Heat moves from the warm room down into the colder ground or the ventilated space beneath the floor. In older homes, air can also come up through gaps in the floorboards and around the skirting.
Insulating the floor slows that heat loss and, done properly, reduces the draughts as well, so more of the heat you pay for stays in the room.
The Two Main Types of Floor in Irish Homes
If you are not sure which you have, a quick look at an air brick on the outside wall, or a lifted corner of carpet, will usually tell you.
Suspended Timber Floors
Floorboards fixed to timber joists, sitting above a void that is ventilated through air bricks in the outside walls.
- Often found in period and early to mid 20th-century houses
- Usually insulated between the joists, with an airtight layer on top
- The ventilation underneath must be kept
- Original boards can often be relaid afterwards
Solid Concrete Floors
A concrete slab laid directly on the ground, with a screed or floor finish on top. Many newer homes were insulated when built.
- Usually found in more modern houses and extensions
- Insulating an existing slab normally means adding a layer on top
- That raises the floor level, which affects doors and skirting
- Often best considered as part of a wider renovation
Four Things That Shape the Right Approach
Every floor is different. These are the details that decide how a floor should be insulated.
Floor Type
Suspended timber or solid concrete. This decides the whole method.
Ventilation
Suspended floors need a ventilated void. Air bricks should be clear and working.
Condition and Damp
Joists, boards and the space below should be sound and dry before insulating.
The Finish You Want
Keeping original boards, laying a new floor, or matching existing door heights.
Insulating Between the Joists
For a suspended timber floor, the boards are usually lifted so the spaces between the joists can be insulated from above.
The insulation is supported so it stays firmly in place, and it is fitted carefully at the edges of the room and around pipes, where gaps would let cold air get past.
The void underneath stays ventilated. In a damp climate like ours, that airflow is what keeps the timbers dry, so it should never be blocked to make the floor warmer.
We explain this type of floor in more detail in our guide to suspended timber floor insulation.
Insulation Alone Does Not Stop Draughts
Many Irish homeowners notice draughts before they notice the cold. Air coming up through gaps between floorboards and along the skirting can make a room feel colder than the thermostat says.
That is why an airtight membrane is laid over the insulated joists and taped around the edges of the room before the floor goes back down.
Insulation slows the heat loss. The membrane stops the air. A good floor insulation job needs both.
What Floor Insulation Looks Like in a Real Home
These are genuine RH Insulation project photographs, not stock images. Real floors have pipes, cables, fireplaces, hallways and stairs to work around, and each one needs the same attention to detail.
Relaying the boards
Working around the stairs
The finished floor
What About Solid Concrete Floors?
Solid floors are insulated differently. With an existing concrete slab, the usual approach is to add insulation on top and then a new floor finish over it.
Because that raises the floor, it affects door heights, skirting, kitchen units and thresholds between rooms. For that reason, insulating a solid floor is often planned as part of a bigger renovation rather than as a standalone job.
Many newer Irish homes already had floor insulation installed when they were built, so it is worth checking what is there before deciding whether any work is needed.
Part of a Warmer, More Efficient Home
Floor insulation does not create heat. It helps your home hold on to the heat it already has, by slowing the rate it escapes downwards and cutting the draughts that come up through the floor.
It works best as part of a whole-house view, alongside the attic and walls, so you can see where the biggest improvements are likely to be.
More Comfortable Rooms
Ground-floor rooms that feel warmer at floor level and hold their heat for longer.
Fewer Draughts
A sealed, airtight floor stops cold air coming up through the gaps.
The Right Method
An approach that suits the floor you actually have, timber or concrete.
How to Get Started
You do not need to know every technical detail before you ask about floor insulation. These are the steps we follow.
Identify the Floor
Find out whether it is suspended timber or solid concrete, and what is already there.
Check the Condition
Look at the ventilation, the joists or slab, and any signs of damp, pipes or cables.
Choose the Approach
Agree a method that suits the floor and the finish you want to end up with.
Install It Properly
Fit the insulation without gaps, seal the floor and keep the ventilation working.
Floor Insulation in Ireland with RH Insulation
The floor is often the missing piece in an Irish home's insulation. If your ground-floor rooms feel cold or draughty, it is worth finding out what is going on beneath your feet.
RH Insulation is based in Dublin and specialises in floor insulation, including suspended floor insulation for older homes. We start by looking at the floor, the ventilation and the condition of the structure, so the work suits your home.
Not Sure What Is Under Your Floor?
Talk to RH Insulation about your home and the floor insulation options that could suit it.
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