When and how to install a Chimney Sheep® draught excluder

The Team at Chimney Sheep® are preparing for the busy cold season and engaging fully in Autumn mode.  The nights are drawing in, the leaves are starting to fall, the weather has turned and Strictly Come Dancing has started!  Families across the UK are starting to have the conversation about putting the heating on.

Heating is a major cost in most households.  For my family, one of the best things about winter is lighting the fire in our living room after a tasty Sunday roast.  We don’t light it more than twice a week usually, and prior to installing a Chimney Sheep, it never really occurred to us that we could block it when it’s not in use.  The University of Liverpool calculated that we lose around 4% of our household heat up the chimney, so as we turn on the heating for winter, we need to be thinking about how best we can stop the heat escaping from our homes.

Take a quick at their “stack effect” air flow calculator. CFM stands for Cubic Feet per Minute. However warm your air is, that’s how much heat you’re losing up your chimney! The Chimney Sheep® is low tech and easy to use, but you need to have an idea of the size and shape of your fireplace. Have a squint into the top of the fireplace. The sheep works by being a little bit bigger than the flue so it can grip onto the sides and hold itself in place. The amount of overlap doesn’t matter too much as the felt is squashy and can fit into a range of gaps.  If you have a head torch it helps for this bit, but if not, just get a regular torch or light and prop it up so you can see up your chimney. Mind out for soot getting in your eyes. Get a tape measure. If you have a round flue, measure the diameter. If you have a round flue, you want a round sheep that is an inch or so larger than the flue.

If you have any other shaped flue, measure the depth and width of the nearest narrowest part. Don’t worry if it’s an odd shape, just measure the widest bits and the wool felt will squash in to fit.  While you’re in there, check the height above the fireplace. The Sheep comes with a 6” (150mm) handle and 6” (150mm) extension rod, and can be extended another 12”. More than that and the extensions get a bit of a wobble on them. It’s easier to fit a large sheep lower down than a small sheep high up.

It’s very important that the handle is long enough – firstly because it’s a lot easier to put in, and secondly the end of the handle must show in the fireplace so that no-one inadvertently lights a fire with the Sheep in place.

If you have a square, oblong, D-shaped, trapezium or similar shaped chimney, use the sizing chart.  Remember that a round sheep will squash into a trapezium or oblong hole.  See their handy draught excluder range sizing chart here. If you have a chimney flue that doesn’t match any of the sizes given you may need to have one made specially – let them know your chimney dimensions and we can give you a quote for getting a bespoke one made. Most people are pleasantly surprised by how reasonable the costs are for a made to measure one.  Visit the online shop here for Chimney Sheep Chimney Draught Excluders, accessories and more.