If the insulation is going below the slab, the damp proof membrane (DPM) is laid next, followed by the insulation, a polythene separating layer, and the concrete slab. As you can see, adding flooring to your existing slab is more straightforward than it seems. In a solid or ground-bearing (because it is continuously supported by the ground across its whole area) concrete floor, the choice of insulation position relative to the concrete slab is commonly linked to the buildings heating system. Here we give our 4 easy-to-follow steps on exactly how to insulate a concrete floor. 29 November 2021 | 10:58 | By Tom Matthews. I would like to subscribe to updates and news from Longley Concrete and have read the, How to Lay a Concrete Floor with Insulation, Laying a concrete floor is a labour-intensive task that requires a few people to help with, Check that your building regulations allow you to make these changes. Register to gain access to our comprehensive technical library which contains helpful specification tools, including BIM objects and much, much more Saint-Gobain Construction Products UK Limited t/a Celotex. There was a problem. Now, its time to install the Interra. Type 2 Polyiso: Which Is Best For Your Project? Finishing a basement is a stellar way to add resale value, and a rental unit, to your home. Now, theres a way to improve your new floors energy efficiency, and it involves a small tweak to the process weve just seen. Installing any amount of insulation will warm the floorboards and go a long way towards eliminating draughts. Use self-tapping concrete screws or nails to attach the wood to the concrete. Company Number 10442670.VAT Reg: 438 3065 50
Bath 
A suspended timber floor tends to be cold and draughty because of the air circulating beneath it. Most modern homes have a solid floor, for example: Insulation is laid on the concrete and covered with a screed. The sub-floor is prepared using well-compacted hardcore and a layer of sand blinding. Achieving a U value of 0.25 would be a good target. Once your concrete has settled, its time to lay your flooring of choice (tiles, floorboards etc.) This will result in a loss of insulation. Per his calculations, Interra panels can support the subflooring with no strapping, just as long as the point loads dont exceed 1,000 pounds. Insulation below the slab suits continuous, low level heating, gradually warming the thermal mass of the concrete and sustaining it at a consistent temperature. Then, staggering the joints, place subfloor sheets with edges on the strapping. with the peace of mind that your room will be properly insulated! Thank you for signing up to Homebuilding. Where insulation is positioned above the slab, the slab and DPM can be installed either way round. When you select your strapping material, keep in mind that the sheets should be thick enough to span the wood strappings with minimal flexing. 
Does Halo Subterra Protect Against Carpenter Ants? The panels consist of a microporous core, which is evacuated and sealed in a thin, gas-tight membrane. Each Halo product features a high-performance graphite polystyrene core, plus an ingenious laminate surface that is customized to its precise usage application, giving you today's most advanced rigid insulation envelope. You can use a laser level to check the correct levelling is achieved. Instead of fitting Interra panels between the strapping as we described above, Matt will: As for the sturdiness of those plywood sheets Matts not too concerned. Heres why you can trust us. tape the joints between the panels and the perimeter bottom plate to form the vapor barrier, loose-lay 2 layers of 3/4-inch plywood sheets and fasten them to each other with screws to create the subfloor. Matt Risinger, a custom builder from Texas, is about to test this method in the field. It might be easier to apply an entire sheet to your area, but if it isnt possible, make sure the DPM edges overlap by about 150mm. Homebuilding is part of Future plc, an international media group and leading digital publisher. For structures like a garage, youll need to reinforce your concrete. You can retrofit floor insulation on top of a solid concrete base, too, but this will have an impact on floor height build-up. Please refresh the page and try again. Saint-Gobain Construction Products UK 2022. Its also a far less tangled process than you think. Type 1 Graphite Polystyrene (GPS) vs. Homebuilding is supported by its audience. VAT Reg: 438 3065 50
If you want help with or more information about the issues we blog about, then lets talk. Lightweight, rigid polyisocyanurate (PIR) foam insulation boards(such as Celotex GA4000 and XR4000), are among the most thermally efficient, commonly available insulation materials. To meet the newTarget Fabric Energy Efficiency(TFEE) and comply with 2014 Building Regulations, theU values will need to be no worse than 0.13W/mfor both the roof and floor. It is said to be more effective than simple fibreglass, as the metalised film reflects heat. They can, however, be installed above the raft slab, in the same arrangement as described above. (MORE:The complete guide to renovating a house). This is to prevent the joist becoming damp and encouraging dry rot. When using Celotex or ISOVER products, you need to satisfy yourself that use of the product meets all relevant national Building Regulations and guidance as well as local, national and other applicable standards relevant for your construction or application, including requirements in relation to fire and applicable height restrictions. Many builders will baulk at this figure it was not long ago that installing 50mm of insulation in the floor was considered fairly advanced. Follow these 5 essential steps to insulate your existing slab with Interra: Interra panels must sit flush against the slab. Registered Offices: Saint-Gobain House, East Leake, Loughborough, Leicestershire, LE12 6JU. It is useful in hard-to-reach spaces and under suspended floors as it can be tacked into place. They keep the depth of the floor construction down, meaning less excavation, and are easily handled and laid to quickly insulate large areas. At the start of a project or extension, its important to think about limiting heat loss in your home with properly insulated flooring. BA1 1UA. 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. Tim is an expert in sustainable building methods and energy efficiency in residential homes. 100-130mm is the recommended amount, and once its laid you should wait 3-4 days for the concrete to adjust to the temperature and moisture of the room. The panels should fit tightly between the strapping keep this in mind when you cut them. Installing insulation on top of the floor can present problems with ceiling, door and window cill heights. Add your insulation on top of the DPM and around the edges of the surface, and then its time to pour the concrete. Ideally, your strapping thickness should match or somewhat exceed that of the Interra panels. The insulation should be pushed tight to the underside of the floorboards. Typically a renovator does not have to meet the same Building Regulations requirements and has more freedom in the amount of insulation installed. Before proceeding with installation, be sure to mark the wood strappings locations on the wall; this will show you where to fasten the subfloor sheets later. They can achieve performance similar to the thickness of traditional insulation at levels ofjust 26mm. Run 2- or 3-inch strapping along the slabs perimeter and place strapping boards every 16 or 24 inches over the entire slab area. When you purchase through links on our site, we may earn an affiliate commission. Once the floors are levelled properly, you can lay the damn-proof membrane (DPM) over your sand layer to ensure the insulation isnt punctured by the concrete stones. While Celotex PIR boards have a good compressive strength, they cannot be laid below a raft slab and take the structural load of the building. This innovative method does away with strapping, thermal bridging, and heat loss and lets you leave out the separate vapor barrier. And the earth below the ground floor will be warmer (in winter) than the external air, so why does the floor need a better U value than the walls? The insulation is then laid, followed by a polythene separating layer, and either a concrete screed or tongue and groove chipboard, ready to receive the specified floor finish. Registered Offices: Saint-Gobain House, East Leake, Loughborough, Leicestershire, LE12 6JU. Halo is the Advanced Graphite Insulation System that's designed perfectly for specific applications. Once the slab is ready, cover its entire surface with an acceptable vapor barrier. Use screed and building sand to level off the area to be as flat as possible. Depending on the use of the building, the slab can then be finished ready for use, or receive a screed suitable for a floor finish.
Visit our corporate site (opens in new tab). For non-domestic uses you should seek the advice of a structural engineer regarding the suitability of any insulation product in a specific floor system.
There will be a damp-proof membrane under the insulation and possibly a second membrane on top, depending on the type of screed. By protruding above the panels, strapping creates the air space needed to reflect heat inside the home and curb heat loss. All rights reserved. For low-rise buildings on poor ground, the floor slab can be designed as a raft to act as the foundation. Rods, bars or mesh are recommended for this. What Is Advanced Framing and Does It Impact Foam Board Insulation? Company Number 734396. This allows the concrete slabs to actually absorb the heat too, which makes overheating unlikely and is our preferred method of concrete insulation. In this application, Interra covers the top surface of the slab and needs a separate vapor barrier. The way the insulation is installed will vary with the type and rigidity of the insulation: The thickness required to achieve a U value of 0.25W/m on a suspended floor is: This is fibreglass insulation encapsulated in a metalised polythene film. It does not constitute advice and should not be relied upon. While it is possible to insulate after pouring your concrete (above the concrete) we recommend insulating below the concrete layer. And its only worth digging out the floor if youre undertaking a major renovation. Thinner polyisocyanurate (PIR) foam insulation boards, such as Celotex TB4000, can be considered for the perimeter upstand insulation. All rights reserved, ISOVER Acoustic Partition Roll (APR 1200), Lightweight, rigid polyisocyanurate (PIR) foam insulation boards, Environment, Health, and Safety Policy [PDF]. For the same reason, any airbricks must be left clear to ensure a good air flow. Thats why your first task is to clear the slab of any debris and remove any protrusions that could lead to damage. Learn More, Now, theres a way to improve your new floors energy efficiency, Read The Technical Bulletin For The Risinger Detail >>. As always, you should always consult the specific sub-flooring manufacturer and always defer to their particular installation recommendations. Longley Concrete are experts in concrete floor insulation. In addition to the product datasheet, please refer to the following product documents: The building detail is for illustrative purposes only. On the other hand, the noticeable impact of the insulation is likely to be greater. In this scenario, arigid foam insulationis usual, and as youd want the same U value in the roof, we need the same thickness of insulation (180mm). The effect is a greater sense ofcomfortand that, in turn, allows the homeowner to turn the thermostat down. Wood strapping fastens the vapor barrier to the slab and holds the weight of the subflooring. Use adhesive, such as PL 400, and screws spaced at 8 inches to fasten the subfloor to the strapping. One-off payment: 4.99 for six months full access to The Planning Hub, The Planning Hub offers in-depth guides to planning permission in England, brought to you by Homebuilding & Renovating's planning experts, THE NO.1 SITE FOR SELF BUILDERS AND HOME EXTENDERS, How to Measure Carpet For Stairs in Four Easy Steps, The 400 Energy Grant Payment Details Have Been Revealed, The 5 Best Bathroom Extractor Fans to Keep Humidity at Bay, Delist a Listed Building: Here's How and Why I Did It, How to Heat a Swimming Pool: The Best Ways Explained, Rigid foams just need a few tacks to ensure they do not drop, Semi-rigid batts will need battens fixed along the joists. Copyright 2022 Longley Concrete Group. Flexible wools will need battens across the joists. At least25mm of the joist must be left exposedto ensure air circulation. How To Properly Fasten Rigid Foam Board Insulation. The most straightforward solution is getting ready-mixed concrete pumped directly into the flooring. Saint-Gobain Isover UK Limited. This is a straightforward, tried-and-true technique for adding flooring to your existing concrete slab. This recognises that a uniform envelope is a good idea. All rights reserved.
Get the latest news, reviews and product advice straight to your inbox. Future Publishing Limited Quay House, The Ambury, If any gaps remain, use spray foam to fill them. This will make sure no moisture seeps into the concrete. All you need are these 5 components to pull off this task: Thanks to Interras strength, you can also eliminate the only thermal bridge in your floor the wood strapping and keep downward heat flow to a minimum. Whats more, the slab surface should be free of any items that can puncture the panels or the vapor barrier. Though it can be a lot of work, if you have a small surface area it is possible for you to barrow it in manually. There are several options for concreting your surface. Kingspan (opens in new tab)s new range of Vacuum Insulated Panels (VIPs) offers an interesting solution for those needing an ultra-thin build-up. You will receive a verification email shortly.
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. The most common insulation sheets are 4 metre sheets. If your job is bigger than just a DIY project, then get in touch and our experts will be on hand to help spec out and get the perfect fitted insulation for your project. However, it makes sense to consider retrofitting, particularly if you have a suspended timber floor. This post will show you a handy way to insulate and add subflooring to your existing concrete slab. Refer to the local code or consult with your building department to pick the right product. 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). But keep these things in mind before you start: Having your floors on a slope means that the insulation boards, once installed, are likely to be uneven and move around. That would need90mm of rigid foamor150mm mineral wool. Where the heating is likely to be turned on and off, such as in new-build domestic properties, and a faster thermal response is required, the floating floor arrangement of insulation above the slab can be more appropriate. Insulating floors is often trickier than insulating other areas of your home. England and Wales company registration number 2008885. The limiting U value (the maximum U value thatcannot be exceeded) required under current Building Regulations are: Heat rises as denser colder air falls and pushes the warmer air up, and is more likely to escape through the roof. If you cant cover the whole area with one sheet, you can lay more but make sure you fill any gaps with foam and tape the sheets down to avoid moisture seeping into the concrete.
A suspended timber floor tends to be cold and draughty because of the air circulating beneath it. Most modern homes have a solid floor, for example: Insulation is laid on the concrete and covered with a screed. The sub-floor is prepared using well-compacted hardcore and a layer of sand blinding. Achieving a U value of 0.25 would be a good target. Once your concrete has settled, its time to lay your flooring of choice (tiles, floorboards etc.) This will result in a loss of insulation. Per his calculations, Interra panels can support the subflooring with no strapping, just as long as the point loads dont exceed 1,000 pounds. Insulation below the slab suits continuous, low level heating, gradually warming the thermal mass of the concrete and sustaining it at a consistent temperature. Then, staggering the joints, place subfloor sheets with edges on the strapping. with the peace of mind that your room will be properly insulated! Thank you for signing up to Homebuilding. Where insulation is positioned above the slab, the slab and DPM can be installed either way round. When you select your strapping material, keep in mind that the sheets should be thick enough to span the wood strappings with minimal flexing. Does Halo Subterra Protect Against Carpenter Ants? The panels consist of a microporous core, which is evacuated and sealed in a thin, gas-tight membrane. Each Halo product features a high-performance graphite polystyrene core, plus an ingenious laminate surface that is customized to its precise usage application, giving you today's most advanced rigid insulation envelope. You can use a laser level to check the correct levelling is achieved. Instead of fitting Interra panels between the strapping as we described above, Matt will: As for the sturdiness of those plywood sheets Matts not too concerned. Heres why you can trust us. tape the joints between the panels and the perimeter bottom plate to form the vapor barrier, loose-lay 2 layers of 3/4-inch plywood sheets and fasten them to each other with screws to create the subfloor. Matt Risinger, a custom builder from Texas, is about to test this method in the field. It might be easier to apply an entire sheet to your area, but if it isnt possible, make sure the DPM edges overlap by about 150mm. Homebuilding is part of Future plc, an international media group and leading digital publisher. For structures like a garage, youll need to reinforce your concrete. You can retrofit floor insulation on top of a solid concrete base, too, but this will have an impact on floor height build-up. Please refresh the page and try again. Saint-Gobain Construction Products UK 2022. Its also a far less tangled process than you think. Type 1 Graphite Polystyrene (GPS) vs. Homebuilding is supported by its audience. VAT Reg: 438 3065 50
If you want help with or more information about the issues we blog about, then lets talk. Lightweight, rigid polyisocyanurate (PIR) foam insulation boards(such as Celotex GA4000 and XR4000), are among the most thermally efficient, commonly available insulation materials. To meet the newTarget Fabric Energy Efficiency(TFEE) and comply with 2014 Building Regulations, theU values will need to be no worse than 0.13W/mfor both the roof and floor. It is said to be more effective than simple fibreglass, as the metalised film reflects heat. They can, however, be installed above the raft slab, in the same arrangement as described above. (MORE:The complete guide to renovating a house). This is to prevent the joist becoming damp and encouraging dry rot. When using Celotex or ISOVER products, you need to satisfy yourself that use of the product meets all relevant national Building Regulations and guidance as well as local, national and other applicable standards relevant for your construction or application, including requirements in relation to fire and applicable height restrictions. Many builders will baulk at this figure it was not long ago that installing 50mm of insulation in the floor was considered fairly advanced. Follow these 5 essential steps to insulate your existing slab with Interra: Interra panels must sit flush against the slab. Registered Offices: Saint-Gobain House, East Leake, Loughborough, Leicestershire, LE12 6JU. It is useful in hard-to-reach spaces and under suspended floors as it can be tacked into place. They keep the depth of the floor construction down, meaning less excavation, and are easily handled and laid to quickly insulate large areas. At the start of a project or extension, its important to think about limiting heat loss in your home with properly insulated flooring. BA1 1UA. 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. Tim is an expert in sustainable building methods and energy efficiency in residential homes. 100-130mm is the recommended amount, and once its laid you should wait 3-4 days for the concrete to adjust to the temperature and moisture of the room. The panels should fit tightly between the strapping keep this in mind when you cut them. Installing insulation on top of the floor can present problems with ceiling, door and window cill heights. Add your insulation on top of the DPM and around the edges of the surface, and then its time to pour the concrete. Ideally, your strapping thickness should match or somewhat exceed that of the Interra panels. The insulation should be pushed tight to the underside of the floorboards. Typically a renovator does not have to meet the same Building Regulations requirements and has more freedom in the amount of insulation installed. Before proceeding with installation, be sure to mark the wood strappings locations on the wall; this will show you where to fasten the subfloor sheets later. They can achieve performance similar to the thickness of traditional insulation at levels ofjust 26mm. Run 2- or 3-inch strapping along the slabs perimeter and place strapping boards every 16 or 24 inches over the entire slab area. When you purchase through links on our site, we may earn an affiliate commission. Once the floors are levelled properly, you can lay the damn-proof membrane (DPM) over your sand layer to ensure the insulation isnt punctured by the concrete stones. While Celotex PIR boards have a good compressive strength, they cannot be laid below a raft slab and take the structural load of the building. This innovative method does away with strapping, thermal bridging, and heat loss and lets you leave out the separate vapor barrier. And the earth below the ground floor will be warmer (in winter) than the external air, so why does the floor need a better U value than the walls? The insulation is then laid, followed by a polythene separating layer, and either a concrete screed or tongue and groove chipboard, ready to receive the specified floor finish. Registered Offices: Saint-Gobain House, East Leake, Loughborough, Leicestershire, LE12 6JU. Halo is the Advanced Graphite Insulation System that's designed perfectly for specific applications. Once the slab is ready, cover its entire surface with an acceptable vapor barrier. Use screed and building sand to level off the area to be as flat as possible. Depending on the use of the building, the slab can then be finished ready for use, or receive a screed suitable for a floor finish. Visit our corporate site (opens in new tab). For non-domestic uses you should seek the advice of a structural engineer regarding the suitability of any insulation product in a specific floor system.
There will be a damp-proof membrane under the insulation and possibly a second membrane on top, depending on the type of screed. By protruding above the panels, strapping creates the air space needed to reflect heat inside the home and curb heat loss. All rights reserved. For low-rise buildings on poor ground, the floor slab can be designed as a raft to act as the foundation. Rods, bars or mesh are recommended for this. What Is Advanced Framing and Does It Impact Foam Board Insulation? Company Number 734396. This allows the concrete slabs to actually absorb the heat too, which makes overheating unlikely and is our preferred method of concrete insulation. In this application, Interra covers the top surface of the slab and needs a separate vapor barrier. The way the insulation is installed will vary with the type and rigidity of the insulation: The thickness required to achieve a U value of 0.25W/m on a suspended floor is: This is fibreglass insulation encapsulated in a metalised polythene film. It does not constitute advice and should not be relied upon. While it is possible to insulate after pouring your concrete (above the concrete) we recommend insulating below the concrete layer. And its only worth digging out the floor if youre undertaking a major renovation. Thinner polyisocyanurate (PIR) foam insulation boards, such as Celotex TB4000, can be considered for the perimeter upstand insulation. All rights reserved, ISOVER Acoustic Partition Roll (APR 1200), Lightweight, rigid polyisocyanurate (PIR) foam insulation boards, Environment, Health, and Safety Policy [PDF]. For the same reason, any airbricks must be left clear to ensure a good air flow. Thats why your first task is to clear the slab of any debris and remove any protrusions that could lead to damage. Learn More, Now, theres a way to improve your new floors energy efficiency, Read The Technical Bulletin For The Risinger Detail >>. As always, you should always consult the specific sub-flooring manufacturer and always defer to their particular installation recommendations. Longley Concrete are experts in concrete floor insulation. In addition to the product datasheet, please refer to the following product documents: The building detail is for illustrative purposes only. On the other hand, the noticeable impact of the insulation is likely to be greater. In this scenario, arigid foam insulationis usual, and as youd want the same U value in the roof, we need the same thickness of insulation (180mm). The effect is a greater sense ofcomfortand that, in turn, allows the homeowner to turn the thermostat down. Wood strapping fastens the vapor barrier to the slab and holds the weight of the subflooring. Use adhesive, such as PL 400, and screws spaced at 8 inches to fasten the subfloor to the strapping. One-off payment: 4.99 for six months full access to The Planning Hub, The Planning Hub offers in-depth guides to planning permission in England, brought to you by Homebuilding & Renovating's planning experts, THE NO.1 SITE FOR SELF BUILDERS AND HOME EXTENDERS, How to Measure Carpet For Stairs in Four Easy Steps, The 400 Energy Grant Payment Details Have Been Revealed, The 5 Best Bathroom Extractor Fans to Keep Humidity at Bay, Delist a Listed Building: Here's How and Why I Did It, How to Heat a Swimming Pool: The Best Ways Explained, Rigid foams just need a few tacks to ensure they do not drop, Semi-rigid batts will need battens fixed along the joists. Copyright 2022 Longley Concrete Group. Flexible wools will need battens across the joists. At least25mm of the joist must be left exposedto ensure air circulation. How To Properly Fasten Rigid Foam Board Insulation. The most straightforward solution is getting ready-mixed concrete pumped directly into the flooring. Saint-Gobain Isover UK Limited. This is a straightforward, tried-and-true technique for adding flooring to your existing concrete slab. This recognises that a uniform envelope is a good idea. All rights reserved.
Get the latest news, reviews and product advice straight to your inbox. Future Publishing Limited Quay House, The Ambury, If any gaps remain, use spray foam to fill them. This will make sure no moisture seeps into the concrete. All you need are these 5 components to pull off this task: Thanks to Interras strength, you can also eliminate the only thermal bridge in your floor the wood strapping and keep downward heat flow to a minimum. Whats more, the slab surface should be free of any items that can puncture the panels or the vapor barrier. Though it can be a lot of work, if you have a small surface area it is possible for you to barrow it in manually. There are several options for concreting your surface. Kingspan (opens in new tab)s new range of Vacuum Insulated Panels (VIPs) offers an interesting solution for those needing an ultra-thin build-up. You will receive a verification email shortly.
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. The most common insulation sheets are 4 metre sheets. If your job is bigger than just a DIY project, then get in touch and our experts will be on hand to help spec out and get the perfect fitted insulation for your project. However, it makes sense to consider retrofitting, particularly if you have a suspended timber floor. This post will show you a handy way to insulate and add subflooring to your existing concrete slab. Refer to the local code or consult with your building department to pick the right product. 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). But keep these things in mind before you start: Having your floors on a slope means that the insulation boards, once installed, are likely to be uneven and move around. That would need90mm of rigid foamor150mm mineral wool. Where the heating is likely to be turned on and off, such as in new-build domestic properties, and a faster thermal response is required, the floating floor arrangement of insulation above the slab can be more appropriate. Insulating floors is often trickier than insulating other areas of your home. England and Wales company registration number 2008885. The limiting U value (the maximum U value thatcannot be exceeded) required under current Building Regulations are: Heat rises as denser colder air falls and pushes the warmer air up, and is more likely to escape through the roof. If you cant cover the whole area with one sheet, you can lay more but make sure you fill any gaps with foam and tape the sheets down to avoid moisture seeping into the concrete.