Cavity Wall Insulation

Hi all,
I have just had a quote for cavity wall insulation. I'm told I have no insulation but thermal blocks. Will I benefit then from insulation as well or is not needed. My house was built in 1995.
Secondly, he will needs to drill lots of holes to blow this stuff in. Can it not be filled from the cavity spaces in the loft? ie pour or blow the stuff down?
Thanks

yes, yes, no

You seem not to trust your installer.

get a quote from your Electricity or Gas supplier to compare it. They usually have "special offers" and in my experience employ contractors who do a good-quality job (as they have a reputation to maintain and are not flybynights)

Be sure you use an established and reputable company anyway.

I had Knauf Supafil CWI installed from Energywise about 3 months ago. I'm in the middle of a major loft conversion so when it was done the tops of the gable walls were exposed and you could look down the cavity and see the mineral wool being blown in.

Basically the wool - when injected into the standard drill hole - will travel a certain distance along, up, down the cavity depending on the size of the cavity and how clean it is. The injection pressure is critical to obtain the optmimum density of material so you can't just pile on the pressure to make it travel further.

My guess is that it will travel about a metre and a half at best, so filling from the roof level is obviously out of the question - which we knew anyway but there you are!

Cost me £249 and I have to say the difference is quite remarkable. The installers made the drill holes good and you have to look really hard to see them.

Many thanks for that John.