A freind lives in an an appartment block (privately owned)and the local council have said they are paying for free cavity wall insulation to be installed as part of their green initiative in the local area, a firm called Hillserver are going to do the work.

What shall i tell her to look for, and any probs, or similar.

She says they are going to drill lots of holes and blow stuff into the wall cavity,(her words), and shes affraid they might drill to far and fill her front room with the stuff.

Had it done the other day – it was quite noisy and they (not the same firm) suggested taking pictures off the wall/things of windowsills at it causes quite a lot of vibrations.

None of our walls got drilled to far, but we had to open the windows for a while afterwards as it was a bit hazy (normal apparently).

Check how far apart they are going to drill for holes as I think there is an industry standard. They should also look out for flues for extractors/chimneys etc. How old is the building?

Best type at the moment seems to be the ‘carbon beads’.
Is it a brick building? Check they fill the holes properly with mortar.

My 2p worth – hope it helps…

To drill too far you have to literally be a complete tool!! Drilling happily away, drill suddenly lurches forward, you’re in the cavity, end of drilling! Move to next hole!!

Drilling to far, i told her of a cable tv installer who loaned his drill to the customer, who then used it to drill the wall and drilled straight into his own radiator, and its worried her.

oxy: did it help with noise reduction much?

is she renting or owning?

lots of potential issues with the blown cavity wall insulation, wouldn’t have it done on a property I owned

oxy: did it help with noise reduction much?

We’re down a fairly quiet cul-de-sac in a 1930’s house (with solid walls inside) so not noticably as it’s pretty quiet anyway.

I am thinking of having it done but am worried about it bridging a damp bit or something causing damp issues on the inside wall.

Or am I just being bonkers? 😕

Modern blown insulation is designed not to encourage the transfer of moisture, and therefore you will be fine on that score.
A couple of things to look out for are as follows:

– Openings: Make sure they do under the windows and above lintels. These are areas often overlooked and can result in cold spots, which encourage damp and eventually mold.

– This probably isn’t relevant to the friend of the OP but check the eaves: Because of the high powered nature of the hoses, it is often no possible to insulate the very top of the external walls as the insulate will just blow out the top of the cavity and spray all over the roof space.

What you can do is go up there afterwards and push some roof insulation down into the cavity, assuming you can get at it of course.

Ultimately, even blown insulation can be a little patchy, but a good specialist should be able to do the job as well as possible.

I have seen thermal images of a house AFTER it has had new insulation blown in and the areas I mention above still register as cold spots.