Wall Insulation

How does the pumped insulation compare to the sheets of insulation?
What have other people used ( thickness, brand and cost approx ideally)
We are trying to decide what to go for, our builder has recommended the pumped stuff.

Pumped insulation is generally used as a retro fit on old houses. A number of holes are formed and the insulation is pumped in. Im not sure why a builder would wish to use it on a new build as it would mean you have no air cavity in the wall.
Is it a new build or existing house?

It is a new build and our builder who works for a building company where they are using it in new estates.

The pumped insulation is a better solution for wall insulation. With aerboard any debris from the blockwork can cause an uneven surface and so the aerboard isn't as effective.

The pumped insulation fits tightly into the space and so provides better insulation. I'm not suprised that it is being used on newbuilds. I know a builder who was considering that option a couple of years ago.

Your best bet would be to get someone to work out the u value of the wall with the pumped insulation and then with the boards. Verifyable date can be gotten off of the Agrément Certificate for the product (if it doesnt have one, don't use it).

There's now a sizeable shift towards using pumped insulation on new builds, when at one time its use was confined to retrofits years ago. The problem with block and bricklayers is that they are not insulation installers and rarely take the time to fit the boards neatly or correctly- they don't get paid to, as such. Whereas I think the Kingspan boards are great they are not favoured by brickies as the boards are very rigid and unforgiving when it comes to installation with the result that badly installed board can perform very poorly in the completed wall envelope. That said I still believe pumped/ blown products are best avoided where the outer leaf is brickwork, which is highly porous in comparison to a rendered background. In any event it is of course imperative to study the Agrement Certificates and ensure suitability of any given product for your installation.