Hi,

We are trying to sort out a few cold spots in our house that I suspect are caused due to a lack of attention to detailing from the builders around air tightness and fitting of insulation. One of the areas I want to try to sort next is a desk area that we have built into our landing.

I have put a couple of photos below, but essentially to the left of the desk there is a boxed out void. I don't trust the air tightness and the fitting of insulation to the exterior brickwork (there is no parge coat in this area like there is the rest of the house).

I've been trying to think about what I can do while causing minimal disruption. We have a plasterer doing some work in the next couple of weeks so I was thinking about getting a hole cut at the top so that we could pour in insulation beads. I was hoping this would add insulation and, while not perfect for airtightness should help there too?

Could I please get people's thoughts on this approach? I've done some searches for EPS beads and couldn't find many suppliers. Would vermiculite (which seems easier to find) be ok?

I realise it will be a nightmare to ever access the void once it is full of beads, but the only thing on that wall is a couple of power sockets, ethernet cable and phone line under the desk so I'm hoping I will never really need access.

Thanks,
Richard

Photo of the boxed out area

It's a bit difficult to offer thoughts without some more information - is this newbuild or an old house refurb? Is this a point at which an extension meets an existing building? What's the construction of the walls and where's the insulation layer supposed to be?

Posted By: lineweightIt's a bit difficult to offer thoughts without some more information - is this newbuild or an old house refurb? Is this a point at which an extension meets an existing building? What's the construction of the walls and where's the insulation layer supposed to be?

Hopefully answering your questions:
- It is a new build, built in 2016

- There is no extension, the whole house was built at the same time

- The walls are a brick and block construction, however, in this area it is basically only the brick window reveal. The green outline on the plan above is the area in question. The windows are set into quite a deep brick reveal (the bottom of the green outline). Kingspan was put up against the bricks, but I don't trust it to have been fitted well and I'm pretty sure there isn't an effective air tightness barrier. Most of the green box is a void. Hopefully that makes some sense!

Warmcell is a blown in insulation so probably expensive for a small item (when call out charge is considered) I don't think it is a DIY job. EPS can be poured in DIY

Posted By: Rex: “Think there was a time when one could buy Warmcell in bags to self-scatter in the loft.�

It needs to be blown into walls under pressure, though, otherwise it'll settle over time. I think you're right, though, that it once could be bought for lofts but not any longer. Cellulose insulation can be bought for DIY installation in the US where you typically rent the pump to install it and, I think, in parts of Europe for loose fill but AFAIK nobody sells it like that in the UK.

BTW it's Warmcel (one 'L'), a trademark: https://www.warmcel.co.uk/