Felt pipe wrap - leave or replace?

[Sparrowhawk]

I've lifted my suspended floor to insulate and the heating pipes are wrapped in something that looks like felt or cotton waste with a plastic layer in it.

 

I'm guessing this doesn't do much for insulation in the vented floor void, but is it worth replacing, and if so with what?

 

 

 

[Redbeard]

If you have the clearance I would use the grey plastic pipe-sleeving, but *not* the 'economy' (approx 10mm wall thickness) stuff. Bldg Regs-compliant stuff has 19-25mm wall thickness, so on a 15mm pipe that's up to 65mm dia. Many pipe runs leave nothing like that much clearance, which is why the hessian wrap you show gets used. Definitely use the plastic stuff if you can.

[marshian]

On 26/05/2024 at 19:38, Sparrowhawk said:

I've lifted my suspended floor to insulate and the heating pipes are wrapped in something that looks like felt or cotton waste with a plastic layer in it.

 

I'm guessing this doesn't do much for insulation in the vented floor void, but is it worth replacing, and if so with what?

 

 

 

 

Looks like they've insulated flow and return together in one bundle - That was done in my house too - I've stripped it all off and insulated each pipe separately - made a massive difference to the return temps at the boiler as there was clearly some heat being lost from the flow to the return pipe driving down the delta at the boiler

[marshian]

I used this https://insulation4less.co.uk/products/tubolit-polyethylene-pipe-insulation-all-sizes

 

I tried to get the OD of both 22mm and 15mm pipe insulation to be the same so I could set up the pipe lagger tool to work with both sizes so that I didn't have to constantly change the width of the cutting box