How To Fill Large Gaps in Hardwood Floors For Greater Thermal Comfort EcoMaster

Gaps in floorboards may appear to be minor from afar, but they can have a huge impact on your home’s indoor temperature and overall thermal comfort. 

Find out why gaps exist in your floorboards and three ways you can fix them prevent them to protect your family from extremes of weather and rising utility bills.

Why are there gaps in floors?

The gaps are a direct result of your floorboards’ expansion and shrinkage during winter and summer.  This will affected by the levels of moisture present above and below the floors. Being made from wood, floor boards undergo expansion in the summer when moisture content is higher, and shrink in the colder months when moisture content is lower. This means that gaps in your floors can get wider in winter, allowing more draught in.

A tiny crack here and there won’t matter until you add them together. An average room has about 80 to 100 metres of gaps if you laid them end to end. These tiny gaps add up to an area measuring 50 x 50 centimetres or about the size of an open window! 

For cracks present in between floor and skirting boards, these can total 20 x 20 centimetres per room, the equivalent of another yet open window.  In addition, the free air exchange between sub -floor and living area can present highly undesirable odours, introducing stale, and musty air from below.

A blow to your comfort and energy cost

In general, draughty homes are wasteful of energy, because they allow expensively heated air to escape while homeowners continue to feel achingly cold. To make your space cosier, people end up blasting their thermostats to improve comfort, which puts them in an unending cycle of wasting more energy without locking in comfort.

Solutions. Below are realistic solutions you might want to try to prevent draught from seeping into your floorboards:

Solution 1: Carpet with good underlay  

Install carpets with good underlay.  This will give you a rating of R1.0 for your floor.  The timber floor is rated R0.7 and the carpet with underlay rates R0.3.  Click here for more details.

Gaps in Floorboards Carpet EcoMaster

Solution 2: Caulking Floorboard Gaps 

If you don’t want to carpet over your beautiful timber floors, you can gap fill your floors to seal the gaps and cracks using Fuller Ultra Clear sealant. This is a water-based gap sealant that is white when applied and clear when dry. You can also apply this sealant on your draughty architraves, skirting boards and air vents.  Click here for video instructions on how to do this. 

There are many discussions in inline forums around how to seal floor board gaps, from the downright silly – “put in tiny strips of timber” – to the very poorly considered – “Don’t, you need to let the floor breath” -. 

Any kind of timber putty is brittle and inflexible.  As the floor flexes, the putty cracks and falls out, or is vacuumed up.  Either way – it’s not there for long.  There is also those who consider silicone to be a choice.  Its not – and here are the reasons why silicone is a very poor choice for caulking

UltraClear Sealant EcoMaster

Solution 3: Installing Underfloor Insulation

Home Insulation 1280px EcoMaster

Install a premium Polyester Underfloor Insulation R2.5 under your floorboards.

Polyester is the most effective, safe, and durable insulation available for insulating under floors. It does an excellent job in improving your thermal comfort, and keeping your winter warmth in, and the summer heat out. This means you won’t have to run your heating, and cooling appliances any more than necessary. You can also enjoy much lower energy bills too.  This will rate a glorious R3.2 – R0.7 timber floor + R2.5 insulation – in conjunction with your timber floor.

For more tips on making your home more comfortable this winter or learn more about your home’s energy efficiency rating, get In touch via our Contact Form


People Also Ask:

⇒ Should I fill gaps in hardwood floors?

There are 3 ways to fill gaps in hardwood floors: 

  1. Install carpet with a good quality underlay – and achieve R1.0 
  2. Caulk with Fullers Ultraclear – no change in R value, but no breeze either
  3. Install underfloor insulation – and achieve R 3.2

⇒ How do I seal unused heating vents in my floors?

If you have decommissioned your underfloor heating system – and good on you! – and are wondering what to do about fixing the holes in your floors.  Its easy.   Leave your vents in place. There is no need to try and match and patch your timber floors. An easy and cost-effective way to decommission your unused floor heating vents and protect your home from draughts, rodents, and energy loss, is with ecoMaster’s Goodbye Heating Vents kit. 

The kit contains everything you need to draught-proof and rodent-proof up to four heating vents once and for all, no matter what happens to the ducting underneath.       Goodbye Heating Vents will provide you with extra safety, comfort and lower energy bills. 

What’s Next?

We hope this article has helped explain how to fill large gaps in your hard wood floors.  Draft Stopping is a surprisingly effective component of retrofitting your home.  

Next, explore some types of underfloor insulation and what to avoid. 

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