When you don't have a preexisting or properly functioning chimney,  insulated twin-wall flue systems are what you need to solve the problem of getting your stove installed.Twin Wall Flue

If you need to create a new chimney system without masonry, you can use sections of highly insulated double wall pipe to solve the problem. In accordance with building regulations, you can build twin wall flues through your ceiling to the roof, where they can safely take the smoke and exhaust gas up and out of your home. Note that you absolutely cannot do this with a standard single-wall flue pipe for safety reasons.

From our years of experience installing and selling flues, we have created this guide to give you all the details you need to decide if you need to use twin wall flues, how you install this type of flue liner inside your chimney stack, or even without any existing chimney stack. We cover it all!


What Exactly Are Unsulated flues?

Stainless steel twin wall flues are also known as double-skin flues or factory-made chimneys. The flue is made of two separate steel walls insulated with high-grade insulation material.

In properties without masonry chimneys, twin-wall flue systems are used with stoves to achieve higher temperatures since you can use them to safely run internally or externally.


What Is The Advantage Of Having an insulated flue?

Installing a twin-wall insulated flue system is fast, easy, and safe. By adding insulation to your chimney, you protect your home from heat from your fire and make your stove perform more efficiently, keeping your home warmer and saving you money. 

Why buy From Flue-pipes.com?

In most cases, you use these systems when there is no chimney in the room where you want to put your wood burner or stove. You can use a twin wall flue system to install a stove in a room that isn't connected to your main chimney, or if you don't have a chimney at all. So twin wall flue pipes are really a bit of a gift. They give you the option to choose to put a woodburner or a stove in almost any room in your home.

If you need the pipe itself, or brackets, adapters, bends, fire stops, finishing plates, and more, at flue-pipes.com we offer low prices on all components of twin wall flue systems without compromising quality. 


Are There Regulations For Insulated Flue Systems?

As flues deal with high temperatures, dangerous fumes, and flammable embers, they are always subject to building regulations.

All UK regulations apply to the installation of a stove or chimney, the link is available at the end of the article.

You will need to pay your local council to certify the work once your twin wall flue is installed. As explained later, the installation is actually pretty easy. We have all the information you need in our installation guides, which we will link to later in the article.


As an example, here are some flue regulations:

  • You must have a safe distance between the pipe and any combustible materials, such as joists and floorboards. Below, for example, you can see how the flue liner doesn't touch the combustible floors.

  • Passing through a ceiling or floor requires firestop plates -- which you can buy here

  • You can't pass through walls or ceilings at more than 45 degrees 

  • A twin wall flue should not have 90-degree bends 

  • Twin wall flues are restricted to four bends 

  • Clipping the twin wall flue together should be done with the male piece on top so that any condensation can run down easily 

  • It is necessary to notify building control unless you are a HETAS engineer

How to Install a Flue System

You might think that installing this type of system could be difficult, but actually, it isn’t. If you have a basic level of DIY experience, then you can do this yourself with tools from a local DIY shop. You might even be able to do it with the tools you have at home. If you feel like this is a bit daunting, then guaranteed, your competent local handyman can do the job. Note: You don’t need to get professional builders to do this. That is a totally unnecessary expense.

If you're thinking about installing a twin wall system in your home, you'll probably wonder how to do it. Generally, twin wall flue pipes are installed externally along the side of a house, or internally.

Depending on your own circumstances, you may want to choose the easiest or most cost-effective method of installing a twin wall system. In either case, you will need to follow all building regulations and ensure the system is well supported from the stove all the way up to the cowl on the top of the roof in order to install twin wall flues, connecting pieces must be clipped together. For this reason, many twin wall pipes cannot be cut to size.

Our Flue Pipes team can assist you with all of your brackets, connectors, and adapters. You can find our high-quality adapter below, and buy it here.

Also see our Installation Manuals


How Hot Does an insulated Flue Get?Twin Wall Flue stainless Steel

These systems have a double wall construction that is key to their performance and safety. As a result of the heating of the flue inside, smoke is able to rise up and leave the stove, allowing it to perform at its best. As well as keeping the outside of the pipe cool, it minimises the risk of fires caused by high temperatures. Due to this, the pipe can be installed safely through a wall or roof.

In spite of that, it is not entirely true that twin wall flues are completely cool to touch. It is always a good idea to keep twin wall pipes a safe distance away from combustibles - the distance could vary depending on the manufacturer and the material used, but is usually around 70mm.
You also need to bear in mind that if there is combustion happening inside the flue (ie burning happening as the smoke rises inside the outflow pipe), then that will create significantly more heat than just an outflow of hot air and smoke. This will definitely cause the outside of the twin wall to get hot. Always treat these systems with caution and put safety first.


Buy a Trusted Flue From Us

The flue-pipes.com team offers a wide variety of options if you are considering a twin wall flue pipe, including our range of ready-to-go flue kits that are readily designed for those in need of a twin wall flue pipe. With a push-together design that is easy to install, including the necessary locking bands, brackets, adapters, and accessories, insulated flue pipes are available in diameters ranging from 5 inches to 8 inches, so that they can be used in a variety of flue system setups. 

Build your own Twin Flue System Kit with clear images and all the help you need here.

Did We Miss Anything? 

Here is our guide to UK regulations or our installation guide.

We did our best to go deep on this one, but you never know.....If you want to know about any other topic, then please checkout our FAQ page.

If you have something more specific, or you need to get your purchase sorted out quickly, then take advantage of our years of experience and head to our contact page.





Or go to the Twin Wall Flue page