No and I know someone who has done it with a small agricultural grain blower fan, worked like a dream.

**5 year thread bump**


Just to clear up potential confusion about full fill insulation and whether it's allowed in the UK: the relevant bit of building regs (for England & Wales) is in Approved Document C (currently last amended in 2013) and it says:

5.15 A full or partial fill insulating material may be placed in the cavity between the outer leaf and an inner leaf of masonry subject to the following conditions:
a. The suitability of a wall for installing insulation into the cavity should be determined either by reference to the map in Diagram 12 and the associated Table 4 or following the calculation or assessment procedure in current British or CEN standards. When partial fill materials are to be used, the residual cavity should not be less than 50mm nominal; and
b. A rigid (board or batt) thermal insulating material built into the wall should be the subject of current certification from an appropriate body or a European Technical Approval and the work should be carried out in accordance with the requirements of that document;

The map and table shows for example that a (newbuild) 100mm full fill cavity with facing brick and recessed joints would be fine in zone 1 (eg London) but not in more exposed zones. But flush joints would make it ok up to zone 3, and that plus increasing the cavity to 150mm would allow you to use such a build-up in any zone including zone 4, the most severe.

Of course all subject to products having certification, etc etc.

That said: any potential downsides of using full fill rigid boards or any reason you wouldn't use them when you want a cavity wall with the best insulation value for a given overall thickness? More liable to bad installation than mineral fibre batts I guess?

No, better to drill from the inside and inject from there with masonry construction, better still is to install batts properly as you go