Loft insulation and pipes

[berty3000]

Hi all,

I live in a bungalow where water and central heating pipes run through the attic. The water and radiators are heated with a combi boiler which is located in the house below the attic.

There is a lot of insulation in the attic but it seems a bit of a mess so I'm thinking of improving it and running new 100mm base insulation between the joists before putting the existing back over the top. I've noticed that much of the piping up there, which is mostly copper, doesn't have any lagging on it. Does this matter providing it is all covered by the loft insulation? There will be a lot of pipework to insulate if lagging is needed.

When putting the new base insulation between the joists, is it ok for that to just go over the top of the pipes that also run between the joists?

Advice appreciated, and many thanks.

 

[Madrab]

If it is covered by insulation then that will certainly help but if insulation is then placed below it, then it will lose the little heat it will get from the house. Hard one to recommend without knowing what the specific situation is like but extra pipe insulation would be a belt and braces and never a bad thing.

 

[berty3000]

If it is covered by insulation then that will certainly help but if insulation is then placed below it, then it will lose the little heat it will get from the house. Hard one to recommend without knowing what the specific situation is like but extra pipe insulation would be a belt and braces and never a bad thing.

Presumably pipe insulation would also reduce the heat they get from the house below? I don't have any desire to run the loft jubilation under the pipes, would be easier to lay over the top and presumably that is sensible anyway to protect them from the cold attic?

 

[Harry Bloomfield]

Presumably pipe insulation would also reduce the heat they get from the house below? I don't have any desire to run the loft jubilation under the pipes, would be easier to lay over the top and presumably that is sensible anyway to protect them from the cold attic?

It will, but I doubt pipe insulation with loft insulation over the top, will make little if any difference to the protection, with the heating off. It will save some lost heat from the pipes, when the heating is on, so probably worth while, from that point of view. Even if you decide not to insulate the pipes, ensure any pipes exposed above the insulation, are protected by pipe insulation.

 

[berty3000]

It will, but I doubt pipe insulation with loft insulation over the top, will make little if any difference to the protection, with the heating off. It will save some lost heat from the pipes, when the heating is on, so probably worth while, from that point of view. Even if you decide not to insulate the pipes, ensure any pipes exposed above the insulation, are protected by pipe insulation.

Thanks mate.

Can I just check - are you saying the main thing is for the pipes to be covered by loft insulation and the pipe insulation is a bonus? Or is the pipe insulation more important?

Also, is it ok to use 15mm lagging on 10mm pipes? I can't find lagging for 10mm pipes. Also unclear how I insulate pipes that curving above insulation.

 

[Harry Bloomfield]

Can I just check - are you saying the main thing is for the pipes to be covered by loft insulation and the pipe insulation is a bonus? Or is the pipe insulation more important?

The pipe insulation will be a bonus against freezing, should the house be unoccupied for a period, but they will give most benefit when the house is occupied, as they will conserve heat in the pipes, when the heating is in use.

Also, is it ok to use 15mm lagging on 10mm pipes? I can't find lagging for 10mm pipes. Also unclear how I insulate pipes that curving above insulation.

15mm should be absolutely fine, providing it is clipped in place, with no gaps.

 

[berty3000]

The pipe insulation will be a bonus against freezing, should the house be unoccupied for a period, but they will give most benefit when the house is occupied, as they will conserve heat in the pipes, when the heating is in use.



15mm should be absolutely fine, providing it is clipped in place, with no gaps.

Thanks mate.

What kind of clips would you use and and how about tape? Also, how to do deal with elbows?

Do you consider loft insulation over the top of the pipes to be a worthwhile benefit on its own?

 

[Harry Bloomfield]

Thanks mate.

What kind of clips would you use and and how about tape? Also, how to do deal with elbows?

Do you consider loft insulation over the top of the pipes to be a worthwhile benefit on its own?

String, duct tape, tiewraps, what ever, just to make sure it stays put, and keeps the split together.

For the elbows, just cut the insulation for each straight bit, at 45 degrees, so they meet. Sometimes, you can get away with cutting a 45 degree slice out of the side, without cutting all the way through.

Good is loft insulation over the top, better is both loft insulation and pipe insulation.

 

[StephenStephen]

Heat to the pipe from rooms below will be utterly insignificant compared to the heat loss from uninsulated pipe.
Heat retention in the pipe from being under loft insulation will be insignificant compared to heat retention from insulating the pipe.

I've insulated our hot pipes in the attic with 22mm thick pipe insulation, seams taped. I've then put the loft insulation over the top.

The cold pipes you'd get away with just being under the loft insulation, and only need to insulate them individually if they're above the loft roll.