Options for cavity insulation

[marshian]

Made an interesting discovery at the weekend now thinking how best to resolve it so throwing it open to the great minds of BH

 

Background 

 

House built in early 80’s - Brick outer skin, thermalite block inner skin with at the time of build an empty cavity.

 

Had a company inject cavity wall insulation for all the external walls (blown in via a large number of holes drilled in the mortar between the bricks)

 

insulation material is white/grey fluffy fibre

 

I was painting my electricity and gas meter boxes which are on an external wall and I dislodged a lump of mortar around the main cable feed into the electricity meter box

 

I can clearly see no insulation material in the cavity below the box - I’d like to fill this cavity as the wall is on the North side of the house.

 

question is do I

 

1. pour bead type insulation in the hole and hope it flows to all the areas where insulation is missing

 

2. Get a cavity wall insulation company to come and add similar to original (and maybe check other wall areas and top up as required

 

3. use a liquid foam?

 

 

[Redbeard]

I imagine the 

1 hour ago, marshian said:

main cable feed into the electricity meter box

is armoured in some way, and not a PVC-sheathed cable. Just in case any PVC-sheathed cables are involved, remember (a) that polystyrene (expanded or extruded) leaches the plasticisers out of PVC cable sheathing (symptoms include PS insulation 'glued' to the cable) and (b) that cables (particularly 'grunty' cables, whatever they are sheathed in) are not meant to be 'tucked up warm' in insulation.

Edited Wednesday at 12:33 by Redbeard

[marshian]

3 minutes ago, Redbeard said:

I imagine the 

is armoured in some way, and not a PVC-sheathed cable. Just in case any PVC-sheathed cables are involved, remember (a) that polystyrene (expanded or extruded) leaches the plasticisers out of PVC cable sheathing (symptoms include PS insulation 'glued' to the cable) and (b) that cables (particularly 'grunty' cables, whatever they are sheathed in) are not meant to be 'tucked up warm' in insulation.

Yeah black armoured cable

[marshian]

Picture

 

[Big Jimbo]

I have never been convinced that blown in insulation get to all the nooks and crannies. I wonder how many other missed bits there might be ?

[marshian]

13 minutes ago, Big Jimbo said:

I have never been convinced that blown in insulation get to all the nooks and crannies. I wonder how many other missed bits there might be ?

I did some thermal images around the house (inside and out) last winter basically all external walls to see if I had any “leaky” areas 

 

it showed an issue under the gas meter box (on the right) but not the electricity box (on the left)

 

it also showed another area that needs looking at on the other side of the house where potentially the insulation has compressed or sunk