Hi guys

 

Not sure if many of you watched the episode in Bristol where they had damp issues etc. I noticed they removed the cavity wall insulation and replaced it with something else. It looked like they removed the silver/grey EPS beads but not sure if that was going in to replace or being removed. I thought EPS beads would be less likely to cause damp problems.

 

Any thoughts?

Think the old stuff had sank and left voids which would give you a cold spots on the wall and would then lead to condensation settling here leading onto damp and mould. 

I think Declan is spot on, the old way of blowing in EPS beads was just to blow them in loose.  This caused several problems, from the stuff running out if a hole was drilled in the wall to it slumping over time.

 

To get around these problems they came up with the idea of blowing the beads in with a thin coating of wet PVA adhesive, the bonded-bead system.   This causes the beads to lock together as a cohesive block after they'd been blown in, so eliminating the problems of slump or them flowing out of holes.

We knocked down a few walls in my old house and burst into the cavity. Was finding white balls for months afterwards. They get everywhere.

Cheers guys. Do you think they put fresh new EPS beads back in with the PVA adhesive? I remember Nick's comments at the end saying all completely insulated or words to that affect.

I would guess so, as I don't think anyone uses the non-bonded bead system anymore, for the reasons given above.  When we had our cavity walls insulated a few years ago (in the old house) they used bonded beads, and there wasn't an option to have just the free flowing beads as far as I can recall.

God, can you imagine taking a wall down  with unbonded beads in it on a windy day! ?

Edited August 9, 20179 yr by curlewhouse

Presumably it helps to be Usain Bolton catch them :-).

 

Who is of course now available.

Edited August 9, 20179 yr by Ferdinand

My folks had a bonded bead system(from Shell IIRC?) fitted in the early eighties. Suffice it that the glue *didn't*.

Can you spray the top with instant aerosol or spray gun adhesive as you dismantle each course?

 

Or can you use some sort of industrial hoover? If a normal hoover can get soil from a posthole, then a big one could do this if attached to a suitable tank.

Edited August 9, 20179 yr by Ferdinand

1 hour ago, curlewhouse said:

God, can you imagine taking a wall down  with unbonded beads in it on a windy day! ?

 

 I don't need to imagine. I've done it. The house we demolished had the cavities filled with loose beads on 2 elevations and what I can best describe as cotton wool in the others.

The loft was insulated with loose polystyrene chips the type of which I've never seen before. They looked like pieces of shredded sheet, 10-20mm in size. 

What a bloomin mess!  

Same in mine, they're shredded polystyrene ceiling tiles. Forget the mess.....fire hazard and all the cables we're entombed in the stuff . Not good removing that when I did the attic out for my boy.