WHAT INSULATION DO I NEED ?
When it comes to insulating floors, it can be tricky to know what kind of insulation you need, especially if you are tackling a renovation project.
Insulating floors is often trickier than insulating other areas of your home. The ground floor beneath a house is generally warmer than the air around it, and so it would perhaps be third on your list of priorities (behind walls and roofs). However, it makes sense to consider retrofitting, particularly if you have a suspended timber floor.
You can retrofit floor insulation on top of a solid concrete base, too, but this will have an impact on floor height build-up. And it’s only worth digging out the floor if you’re undertaking a major renovation.
The Importance of Insulating Floors
The limiting U value (the maximum U value that cannot be exceeded) required under current Building Regulations are:
- Roof: 0.20W/m²
- Ground floor: 0.25W/m²
- Walls: 0.30W/m²
INSULATING A SOLID FLOOR
Most modern homes have a solid floor, for example:
- concrete slab
- concrete planks
- block and beam
Insulation is laid on the concrete and covered with a screed. There will be a damp-proof membrane under the insulation and possibly a second membrane on top, depending on the type of screed.
In this scenario, a rigid foam insulation is usual, and as you’d want the same U value in the roof, we need the same thickness of insulation (180mm). Many builders will baulk at this figure — it was not long ago that installing 50mm of insulation in the floor was considered fairly advanced.
INSULATING A SUSPENDED FLOOR
A suspended timber floor tends to be cold and draughty because of the air circulating beneath it. Installing any amount of insulation will warm the floorboards and go a long way towards eliminating draughts. The effect is a greater sense of comfort and that, in turn, allows the homeowner to turn the thermostat down.
Achieving a U value of 0.25 would be a good target. That would need 90mm of rigid foam or 150mm mineral wool. A semi-rigid material is generally best as it can be cut very slightly oversized and squeezed in between the floor joists, thereby ensuring no draught-causing gaps.
VAT £39.98 INC VAT
100mm Celotex GA4000 PIR insulation for floors-walls-roofs 100mm Celotex GA4000 PIR insulation for floors-walls-roofs is a general purpose insulation board for floors, walls and roofs. It has long been at the heart of the Celotex product range providing the user with a range of thermal insulation solutions. With low emissivity foil facings, GA..
VAT £74.40 INC VAT
Kay Metzeler EPS70 Expanded PolystyreneAn expanded polystyrene insulation board ideal for floor and wall insulation, Kay-Metzeler EPS70 provide a long lasting thermal solution. The polystyrene board is easy to cut to any shape making it ideal to fit to any space.Expanded Polystyrene (EPS) is proven in use over decades across the globe for const..
VAT £51.23 INC VAT
Kingspan Thermafloor TF70High performance floor insulation Kingspan Thermafloor TF70 is a high performance insulation with a fibre-free rigid thermoset polyisocyanurate (PIR) core.It used to insulate solid concrete and suspended timber ground floors, and has a thermal conductivity of 0.022 W/m·K.Thickness: 100mmAll thickness : 2..
VAT £63.22 INC VAT
100mm Kingspan Thermapitch TP10 pitched warm roof Insulation100mm Kingspan Thermapitch TP10 pitched warm roof Insulation is a high performance insulation with a fibre-free rigid thermoset polyisocyanurate (PIR) core.It is suitable for tiled or slated pitched warm roof spaces, and has a thermal conductivity of 0.022 W/m·K.Thickness: 100mmSize: 2400x..
VAT £31.20 INC VAT
Polystyrene EPS Facade white External Premium (White) EPS Board is used for external wall insulation. It works well in conjunction with a finish of timber or plastic weatherboarding, tile hanging or any other cladding or reinforced-render systems. Thickness: 100mmLenght: 1000 mmWidth: 500 mmAvailable thicknesses: 10mm,20mm,30mm,50mm,80mm,100..
100mm Quinn Therm QF PIR Insulation Board - 2400mm X 1200mm100mm Quinn Therm QF PIR Insulation Board - 2400mm X 1200mm is a high performance, fibre free board, with a rigid thermoset insulation core and faced on both sides with a low emissivity composite foil facing.The high compressive strength of Quinn Therm QF enables it to withstand the dead an..
VAT £43.80 INC VAT
Recticel Eurothane GP PIR BoardEurothane® GP is a high performance PIR insulation board that is light weight, easy to cut, handle and install. Whether it’s a pitched roof, framed wall or floor, Eurothane® GP is the ideal solution amongst contractors and installer.Eurothane GP will not degrade or deteriorate due to moisture and therefore m..
100mm Soprema XPS SL Rigid Thermal Insulation Board100mm Soprema XPS SL Rigid Thermal Insulation Board is used in Floor Insulating applications and boasts a moisture absorption of around only 2% after long term use due to immersion, diffusion or freeze-thaw resistance. The benefits of the sheets are they can withstand heavy loads on top and are lig..
100mm Thermafleece Cosywool Sheep wool Flexi Slab 1200mmx390mm (Pack/21)Thermafleece CosyWool – Sheep's Wool Flexible Slab100mm Thermafleece Cosywool Sheep wool Flexi Slab 1200mmx390mm (Pack/21) is a versatile insulation made from 75% British sheep's wool. and 25% recycled polyester A great choice for insulating walls and roofs. Research show..
100mm Thermafleece Cosywool Sheep wool Flexi Slab 1200mmx590mm (Pack/14)Thermafleece CosyWool – Sheep's Wool Flexible Slab100mm Thermafleece Cosywool Sheep wool Flexi Slab 1200mmx590mm (Pack/14) is a versatile insulation made from 75% British sheep's wool. and 25% recycled polyester A great choice for insulating walls and roofs. Research show..
100mm Thermafleece CosyWool Sheep Wool Roll (6.5mx370mm pack of 3) Rich in British sheep's wool - easy to install between and over joists, ideal for floors and lofts100mm Thermafleece CosyWool Sheep wool roll (6.5mx370mm pack of 3) is versatile insulation rich in British sheeps wool and is the ideal choice if you are looking for all roun..
100mm Thermafleece CosyWool Sheep Wool Roll (6.5mx570mm pack of 2) Rich in British sheep's wool - easy to install between and over joists, ideal for floors and lofts100mm Thermafleece CosyWool Sheep wool roll (6.5mx570mm pack of 2) is versatile insulation rich in British sheeps wool and is the ideal choice if you are looking for all roun..
Xtratherm Thin-R XT/PR Xtratherm Thin-R range is a high performance foil faced Polyisocyanurate (PIR) insulation with a certified thermal conductivity as Low as 0.022 W/mK. Thin-R Pitched Roof XT/PR on sloped roofs (ventilated, hybrid or warm) provides the most efficient U-Values with minimal intrusion into valuable living space. The roof co..
VAT £33.60 INC VAT
Graphite EPS for External Wall Insulation Graphite EPS for External Wall Insulation or grey polystyrene (graphite eps) for external wall insulation which can be used on all kinds of base surfaces and these are ideal for both new and old buildings, blocks of flats and non-residential building. Thickness: 100mmLenght: 1000 mmWidth: 500 mmAvail..
VAT £108.42 INC VAT
Price is based on the minimum order quantity per line.Carriage may be charged depending on how much is taken and where it's going.10mm Marmox Multiboard waterproofing Board10mm Marmox Multiboard waterproofing Board is ideal for many applications. In addition to being a lightweight tile backer board option, it is used for waterproofing, dry-lining a..