Plumbing – How to reduce heating of cold water pipes in the ceiling space


On a hot day our kitchen cold tap, if it hasn't been run for a while, will produce water at a temperature up to around 50-55 degrees C shortly after it is turned on. We haven't measured the exact temperature, but it's too hot to keep our hands in it.

Our house is only a few months old, so we had the plumber check the cause (in case the hot water pipes were too close, or similar) but the heat just appears to be from the ambient heat in the ceiling space, which the water pipes go through. I believe the plumber has since put some lagging around the pipe, but it hasn't prevented the problem.

Adding extra insulation around the pipe will obviously reduce the severity of the problem. What is the best type of insulation to use, and are there any techniques I can apply to get the best result? Is there anything else (within a sensible budget) that we can do?

Best Answer

If you dont want to run a new pipe you will need specific insulation

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Notice that this insulation has a shiny outside layer. This acts as a reflection for heat, and usually has a black/dark side on the inside.

The foam/glass wool used to wrap the pipe needs not be anything special, but I am sure there are special ones that locks out heat better.. instead of the conventional one that keeps heat in.. is there a difference? I am not sure.

Look at this insulation- They wrap silver around the pipe and then insulate it. You DONT want to do this.. because this keeps the heat INSIDE the pipe, and the insualtion slows down absorption of coldness form the earth

As commented- it has no difference--inside or outside- it will deflect the heat in both cases... This is open to debate though.

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So you are looking for Glass Wool Pipe Insulation with reflective outer shield

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