Insulating Pipes – DIY Step-By-Step Guide

Fri 28 October 2016

Two types of pipe insulation are commonly available. The first is made out of a glass fibre or mineral wool material similar to that used for insulating loft floors, but supplied in bandage form (75 to lOOmmI3 to 4in wide and 1 OmmJ3/Bin thick) generally with a flimsy plastic backing. The second type comes in the form of split sleeves which are made from some sort of foamed material — usually plastic. Both types of pipe insulation have their advantages and disadvantages (see below) and both types are cheap And since there is no reason why they can’t be used side by side on the same pipe system, you’ll almost certainly find that the easiest way to insulate your pipework is by using lengths of both.

Insulating Pipes - DIY Step-By-Step GuideFitting bandage insulation The bandage type is fitted by wrapping it around the pipe in a spiral, with each turn overlapping the previous one by at least 10mm (/8jfl). It doesn’t matter which way round the plastic backing goes. Make sure that the bandage is sufficiently tight to prevent air circulating between the turns, but don’t pull it too tight or you will reduce its effectiveness. When starting or finishing each roll, and at regular intervals in between, hold it in place using plastic adhesive tape or string. Tape or tie the bandage, too, on vertical pipe runs and on bends as these are places where the turns are likely to separate. And don’t forget to lag any stop-valves properly — only the handle should be left visible. Apart from being rather more time consuming to install than split-sleeve insulation the main drawback with the bandage type is that it is difficult to wrap round pipes in awkward places, such as those that run under floorboards. For pipes like these you will generally (md that sleeves are more suitable since once fitted they can be pushed into position.


Fitting split-sleeve insulation Split-sleeve insulation normally comes in 1 m (3ft 3m) or 2m (6ff 6in) lengths. It is available in a variety of sizes to fit piping from 15mm (1/2in) to 35mm (11/2in) in diameter. The thickness of the insulating foam is generally around 12mm (½in). Make sure that you buy the right size sleeve for your pipes — if the sleeves don’t fit snugly round your pipework they won’t provide satisfactory insulation. Both flexible and rigid sleeves are available, but as the rigid type isn’t much use for pipe- work that bends frequently, you’d probably be better off using the flexible variety. Fitting the sleeves is very straightforward. You simply prise apart the slit that runs along the length of the sleeve and slip the insulation over the pipe. It’s advisable to tape the sleeve at intervals, arid you must do so at joins. At bends, where the sleeves will tend to come apart, you should tape the split lengthways. Once sleeve insulation has been fitted, it can easily be slid along a length of pipe to protect a part of it that may be hard to get at. However, you should bear in mind that it won’t be able to get beyond any pipe clips, very sharp bends or bulky joints it may encounter. You’ll find that most flexible sleeves will readily slide round curves and even 90° bends made using soldered fittings, but whenever you run up against problems in the form of bulky compression elbows or tee connectors the sleeves will have to be cut accordingly. However, in some circumstances you might well find that bandage insulation provides the better solution.