Central heating insulation-pipes through garage+holes inwall

[edeveuk]

I have a 1987 house where the boiler is in the utility and the pipes between the boiler and the rest of the house runs through the garage- fab.

The pipes where lagged with 13mm PE foam insulation- but with gaps and areas exposed (central heating does not keep its heat). There was also loft insulation around the covered pipes.

I've started to renew with a larger wall thickness- some of the pipes are 12mm and some 28mm, I am going for a climaflex wall thickness of 19mm and 25mm where space will allow . But as usual I've uncovered some other challenges.....

Id be grateful for some advice.........

Does the addition of loft insulation after putting PE foam in add anything really?
There is a couple of decent holes where the pipes go into thehouse and back out- they were stuffed with insulation, would I be better off sealing with an expanding foam- or is the potential heat from pipes a nono with these products?

Thanks for the help

ed

 

[doitall]

The thicker and better the lagging the better.

Are the pipes sleeved through the wall.

 

[edeveuk]

the pipes have a traditional sleeving on- not very thick, I am tempted to cut off and replace with a PE foam where space allows

 

[doitall]

You can always trim the back where it touches the wall, the thicker the better though.