Material to use to fill gaps around very hot pipes?

Joined
18 Jun 2016
Messages
129
Reaction score
4
Country
United Kingdom
Hello,

I have gaps in my ceiling, where the central heating pipes feed to the boiler.

When the extractor fan is on, we can feel the air coming back through the pipes. In the winter we can also feel the cold, what can I use to cover the gaps in the pipes which is safe to use on these hot pipes?


I have attached a picture of the gap.

Thank you.

IMG_0069.JPG
 
Sponsored Links
More importantly I think you need to check that the fan is actually venting outside with no leaks to inside, it sounds like it's venting into the void. If it's supposed to be venting humid air outside then it can cause condensation in the void.
Regarding the gaps I'd probably squirt in some excpanding foam or stuff insulating wool if the appearance isn't important and I had some around. But if it's on show you'd probably want some collars and caulk https://www.screwfix.com/c/heating-plumbing/pipe-covers/cat831640
 
More importantly I think you need to check that the fan is actually venting outside with no leaks to inside, it sounds like it's venting into the void. If it's supposed to be venting humid air outside then it can cause condensation in the void.
Regarding the gaps I'd probably squirt in some excpanding foam or stuff insulating wool if the appearance isn't important and I had some around. But if it's on show you'd probably want some collars and caulk https://www.screwfix.com/c/heating-plumbing/pipe-covers/cat831640


Hi John,

The extractor fan is for a hood in the kitchen, do you still recommend I check? I checked last night with a smoke pellet and saw the smoke come out from the outside vent. But some was returning via the gaps.

Is the expanding forma and insulating wool fire resistant, the pipe go direct to the boiler and therefore are extremely hot.
 
You're talking about pipes containing hot water?

Hot water is not hot enough to start a fire.

Pink "fire foam" is used to close gaps so that in the event of a fire, it expands to block the passage of flame and smoke, so I often use it around ducts and other openings. Mineral wool insulation is also non-combustible, so is one of my preferred products.

But even ordinary pipe insulation is sufficient with hot water pipes.

It sounds like the duct from your extractor is damaged or very badly fitted. Look at that first. Does it go straight through the wall?
 
Last edited:
Sponsored Links
yes you still need to check as any ventilation should go outside 100%. Could just be the joint with the terminal is not securely sealed, or could be damage to the duct. It's common that the terminal is very restrictive, so the pressure in the duct could easily cause a leak.
Regarding the foam/wool, either would be able to withstand 80c or whatever the pipes are. The wool would last better under heat though.
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Back
Top