Cavity wall insulation - fiber vs beads

movilogo

I need to insulate cavity walls for 1960s detached house. It seems suppliers who do beads push for beads and those who do fiber/mineral wool do for fiber.

From consumer's point of view, which one is better?

I have done customary internet search but still not able to figure out if one is clear winner over another.

I have not got prices from suppliers yet so don't know whether price can influence me but at this point I am comparing without considering price.

tacpot12

I'm not an expert on this subject, but there seems to be more potential for the insulation to fail with fibre, and it will not work well if it gets wet, and the cavity inside a well is expected to have water inside it. (This is why cavity trays and weep vents are needed.)

With beads, the issues seem to be more that the cavity may not be completely filled due to installer error (which can also happy with blown fibre) but then the beads don't always set, such that any maintenance on the house at a later date is hampered by large quantities of beads flowing out of the cavity.

Your third option might be external wall insulation on the outside of the cavity wall. This is going to be more expensive than insulating the cavity, but if you also need to put a new roof on the property around the same time, you will get a much warmer and robust result if you fit external wall insulation and a larger, better insulated roof. While the cost will be horrendous, it will renovate the property to a very high level of energy efficiency making it much more likely that a small heat pump will be able to heat the house in future. 

Chickereeeee

Beads. Fibre can hold and wick moisture.  Beads cannot do either, and is also used across Europe.

Despite a lot of searching I did not manage to find any real reports of failure of Beads. Only  the theoretical possibility of ants invading.

Plus, SHOULD beads have to be removed, it is possible, much more easily than fibre.

FreeBear

Chickereeeee said: Plus, SHOULD beads have to be removed, it is possible, much more easily than fibre.

I think quite a few installers inject an adhesive along with beads to stop them coming out of the wall should you need to make a hole in it. Adhesives would make removal just as much of a pain as fibre.

Chickereeeee

FreeBear said:

Chickereeeee said: Plus, SHOULD beads have to be removed, it is possible, much more easily than fibre.

I think quite a few installers inject an adhesive along with beads to stop them coming out of the wall should you need to make a hole in it. Adhesives would make removal just as much of a pain as fibre.

Yes they are bonded beads.

No, there are methods to remove: for tricky areas I believe they stick a rod into a hole ( hopefully same one that was used to pump the stuff in). The rod has something like strimmer wire attached. Rotate rod fast, by attaching to  drill, and the beads break apart and can be sucked out.

OK, still laborious, but possible.

 In fact, the beads are only lightly held together anyway, just enough to prevent them flowing out. So lightly, that you can't pick a piece up without it breaking apart.  I think you could suck them out directly in the majority of cases, should you ever need to do so. (I have tried it on a lump I had, and it sucked up  easily, but it was not in a wall.)

Kiran

Beads are recommended if the cavity is dirty, mortar snots etc. They are bonded with an adhesive, its always a gamble if the installer is going to try and save a few pence and leave it lean. You typically find out when windows are hanged or a new opening is cut into the building.

Blow fibre, if the cavity is clean has less constituent parts so in theory is harder to mess up. It does however have a greater chance of creating damp across the cavity if it gets hooked up on mortar snots etc.