Should new loft conversion to regs retain heat well, or will always lose heat fast?

[lozcozard]

Had a new loft conversion to regs. So it's supposed to have whatever the insulation is supposed to be to conform to regs. Looks like 100mm. It's hard/blocks of foam in walls in eves and looks like wool above ceiling. I can't see the whole ceiling though, only the bottom of it when I'm eves.

But after heating it with radiator and heating goes off it cools down quick and is much colder than the rest of the house.

Is this normal? I thought the insulation is supposed to keep it well insulated.

It does have 6 velux windows.

So am concerned it's not insulated properly. On the other hand if it's normal seen as it is the roof after all then I can stop being concerned. Rest of house has cavity wall insulation.

 

[johnny2007]

6 velux windows???
How big is this loft?
Lofts are always cooler than lower floors, no matter how much insulation you use.
However, it shouldn't be losing heat too quickly, let's say 3 degree/hour.
My loft conversion loses roughly 1 degree every 2 hours and I didn't go mad on insulation .

 

[lozcozard]

It's about 7m by 4m. 4 velux west facing, 2 velux east facing.

I've bought some temperature monitors from Amazon that record it in an app so I can see it over time and compare to elsewhere in the house.

I'm hoping it's not heated up fast enough as opposed to losing temperature quick. The radiator for example is probably not big enough for such a room size and we keep door to attic closed in case it is losing heat. Will check temperature drop when I get the monitors.

 

[johnny2007]

Whoever designed your loft has made too many holes in the roof.
4 velux would've been more than enough.
As said, unless you pack lots of insulation on the inside and lose headroom, the loft will always lose heat faster.
Try going up a ladder to gutter height and see how much colder is up there compared to ground level.
Also, sizing radiators correctly is important.
I have seen lofts with tiny vertical designer radiators that look pretty but are not up to the job.
28 sqm plus eaves takes a lot to warm up.
As a guess, you need at least 8000btu to get somewhere, so probably 1600 type 22 panel radiator or designer equivalent.

 

[lozcozard]

If it's expected to be colder then it's not so bad. Maybe my expectations are too high. It's already not a high ceiling so I think I'd rather it be a bit colder than lose another say 100mm for more insulation.

I can see the insulation is like white wool but inside these fiat silver bags, and looks like 2 layers of them but don't know if there's more further in. They don't look 50mm each.

 

[Notch7]

I can see the insulation is like white wool but inside these fiat silver bags, and looks like 2 layers of them but don't know if there's more further in. They don't look 50mm each

Is it a multi foil

they need an air gap either side to work

 

[lozcozard]

 

[lozcozard]

Is it a multi foil

they need an air gap either side to work

Not sure if you can tell from those images

 

[lozcozard]

It's supposed to be this as per drawings but I don't know. I can't see or feel anything that's 105mm thick. It's just a few of those silver sheeting things above plasterboard.

 

[freddiemercurystwin]

So the question is what has been installed? Can't tell from those pics.

 

[Notch7]

The first image looks like act is hubris.

have a look on their website and see the installation instructions.

I always wonder how much the thermal performance of multifoil systems is compromised with incorrect / poor installation.

ACTIS Insulation - Tomorrow's insulation today

ACTIS offer reflective insulation products providing unrivalled thermal performances for use on roofs, walls and ceilings

www.insulation-actis.com

 

[lozcozard]

But the actis hybris 105mm looks like some sort of honeycomb system that's 105mm thick. I can't see that. But those sheets could be the actis tri-iso super 10.

The first image may be deceiving. The foil between my thumb and finger is the top of vertical kingspan on walls, not ceiling insulation.

 

[Notch7]

But the actis hybris 105mm looks like some sort of honeycomb system that's 105mm thick. I can't see that. But those sheets could be the actis tri-iso super 10.

The first image may be deceiving. The foil between my thumb and finger is the top of vertical kingspan on walls, not ceiling insulation.

Image 1 looks like the side view of actis hybris the whitish foam at the top of the picture is the honeycomb

image 2: cowboy install, it’s showing the A) LHS of rafter space filled with actis hubris roll that’s not long enough and an offcut shoved in to fill the gap - if you look to the right of the picture you can see the honeycomb, but it’s squashed up.

Ive fitted hybris actis so I know what it looks like

 

[lozcozard]

I'm going to upload a video to drop box as I really don't think there's a 105mm insulation there and looks like a few of those sheets only.

 

[lozcozard]

Ive fitted hybris actis so I know what it looks like

So it can squash down? So not 105mm?

The video is a lot clearer it's uploading will post link here shortly.

Thanks for replying!