Internal rainwater pipe insulation?

[ashthekid]

I have a couple of box gutters that are draining internally through a cavity wall space. I know that isn’t ideal but had to be done because of various party wall conditions with the neighbour. 
 

I want to insulate this pipework to protect against acoustic potential and also to stop any potential condensation that maybe produced because of it being located in a cavity space. 
 

Has anyone used Rocklap before or an alternative product or maybe a different idea to insulate it quickly and easily? It’s soil pipe size.

I attach some details on the Rocklap.

[PeterW]

Used on process engineering pipe work. Brings back memories of a summer job in about 1993 sticking the foil onto that stuff ..!! 

[ToughButterCup]

9 hours ago, ashthekid said:

I have a couple of box gutters that are draining internally through a cavity wall space.....

 

Morning.

I'm tinkering with an idea to hide an external downspout between the wall and the back of some wooden cladding. Have you found a downspout that is particulalrly thin .... if you have, could you post a link please?

[PeterW]

20 minutes ago, ToughButterCup said:

Have you found a downspout that is particulalrly thin ....

How much space have you got ..??

[ashthekid]

My cavity space is unusually massive because of structural specifications so am using a 110mm pipe. 
 

So nobody has used the Rocklap that I attached earlier? I’ve never heard of it before but it seems good on paper. 

[ToughButterCup]

Ermmmm,  75mm ish....

( Apologies @ashthekid for hijacking your thread)

[ashthekid]

Or perhaps this Superfoil wrap will work better?

 

@ToughButterCup get your own thread ??

 

 

[ToughButterCup]

?

[PeterW]

@ashthekid superwrap is not suitable 

[PeterW]

40 minutes ago, ToughButterCup said:

Ermmmm,  75mm ish....

( Apologies @ashthekid for hijacking your thread)

standard downpipe is 68mm

[Adrian Walker]

1 hour ago, ToughButterCup said:

 

Morning.

I'm tinkering with an idea to hide an external downspout between the wall and the back of some wooden cladding. Have you found a downspout that is particulalrly thin .... if you have, could you post a link please?

 

If you want to reduce noise in a down pipe then a Syphonic drainage system is very good, more commonly used in commercial buildings.

[saveasteading]

I don't like, and have never specified syphonic. It is clever and works in principle, but risky, and I have always found a safer solution.

Weighing up an irritating noise against risk of leaks and flooding is easy.

 

Have observed the use of syphonic in a commercial building and seen it go wrong due to occupier lack of maintenance.

It works on the principle that the downpipes are deliberately downsized, not running freely, become completely full of water and then suction kicks in. There is no plan B if there is a problem, unless you can build in a substantial overflow somewhere safe.

my checklist:

 

1. Get the gutter and pipes outside the building wherever possible or asap in the run.

2. Have a secondary outlet of pipe or weir, and a substantial gutter.

3. Ensure the flow is smooth (no sharp bends), fit an effective leaf guard, and a means of rodding.

3. Sound insulation inside, as above, then box round for some solid barrier too, and stuff the box with fg. 

4. think of any sounds as connection with nature, and evidence that the pipe is running freely.

5. check and clean gutter frequently.

 

All that, or find a way of having conventional external drainage.

[ashthekid]

What product would you recommend exactly for insulation inside around the downpipes?

 

Mine are all already installed and ready to be insulated with something. I just want to make sure I get the right product and don't waste money on something else that is awful and inefficient at soundproofing and thermally protecting from any moisture/condensation on the internal pipework(which is soil pipe size) before the next wall layers go on.

 

Apart from the Rocklap I suggested in the beginning, is there anything else similar and possibly cheaper?

[saveasteading]

Rocklap if you can fit it, and then make a box and stuff it with fibreglass, or line with cuts of wall batt.

Plasterboard over the box will help too.

 

do you have an alternative outlet if the rain doesn't all get down that pipe

[ashthekid]

No alternative outlet sadly, this was the only option. It's quite a wide cavity space that the pipe is in and it's just by the living room kitchen area so I just want any noise from rainwater to be at a minimum. I have a large roll of TXL foil insulation that the builder said I could use to wrap it with but I'm not sure it will do the job very successfully.

I'm trying to get hold of RockLap quickly though, that's likely to be my next problem.

And what thickness of RockLap?

Edited May 25, 2021 by ashthekid

[saveasteading]

 As thick as will fit,  so any thickness then stuff the rest of a box-out.

[Carrerahill]

16 hours ago, ashthekid said:

I have a couple of box gutters that are draining internally through a cavity wall space. I know that isn’t ideal but had to be done because of various party wall conditions with the neighbour. 
 

I want to insulate this pipework to protect against acoustic potential and also to stop any potential condensation that maybe produced because of it being located in a cavity space. 
 

Has anyone used Rocklap before or an alternative product or maybe a different idea to insulate it quickly and easily? It’s soil pipe size.

I attach some details on the Rocklap.

 

I have an internal soil pipe that also carried roof gutter water for about a year (until the build was on far enough I could fit the external downpipes) - the soil pipe serves the upstairs bathroom, so gets a fair bit of use and runs down a wall in the kitchen. I had the same concerns as you, acoustics and condensation.  

 

To deal with this I protected the void with a VCL, ensured it was also essentially ventilated, and then sorted the acoustics by building a sturdy frame around the pipe and sheeting around the pipe in in OSB then 12.5mm PB. Once skimmed, when the shower is running or WC flushed, you would need to be standing in kitchen, in total silence, listening for it. I also ensured that it was a straight single piece of pipe to reduce noise creators like bosses and connections. I am happy with the solution and it was easy to do.

 

I went under the house during the winter and had a look for signs of condensation running down the pipe and there was nothing, if it did however, as it touches nothing it would run to ground level where ventilation would deal with it.

 

 

Edited May 25, 2021 by Carrerahill