Flooring Question

Insulating a suspended wooden floor

I live in a Victorian end terrace with suspended flooring and have exposed wooden floor boards. During the winter it gets very cold with very noticeable draughts coming through the floorboards.

My wife and I would like to keep the exposed flooring so I have been told that Kingspan insulating boards wedged between the underfloor joists will be a good way of remedying this. I went under the floorboards the other day and there is about a 3ft gap underneath so I should have enough room to install strips of Kingspan.

However, having looked online I have found conflicting views as to how much ventilation should be left between the Kingspan insulation and the underneath of the floorboards.

Therefore, I am after some advice how I should install and fix the insulation boards with respect to how much room I should leave between the insulation board and the underneath of the floorboards.

Many thanks in advance for any advice.

2 Answers

Best Answer

Hi Chris
Theres a type of insulation on the market called multi foil . Brands such as triiso super . And super quilt .
It's only one inch thick and flexible . Invest in a t50 stapler and a roll of this , oh and a very good pair of scissors as it does not cut with a knife .
Staple this directly to the underside of the boards not the joists . This will leave the whole under floor still ventilated and will insulate the floor better then the messy , awkward , smelly kingspan , and you'll have no waste apart from what's left over . It comes in 15m2 rolls . @ around 150£
Its the best thing since sliced bread .

Answered 5th Sep 2012

Apex lofts

Member since 25 Jan 2012

you should have air bricks installed under the floor for ventilation, if so you can fill the gaps between joists completely, if you put some nails in the bottom of the joists this will prevent the kingspan from falling through if it is a bit loose, rgards Terry.

Answered 3rd Sep 2012

tm property services

Member since 9 Mar 2011

Need help with your project?

We have tradesmen ready to help you. Post a job, read reviews and hire today.

Post a job

Need some help?

Post a job on MyBuilder to find quality, local Flooring Fitters who can help you with your project.

Search all questions