Most effective easy-to-fit insulation on lo wall?

New Topic
This topic has been archived, and won't accept reply postings.
 Si dH 21 Mar 2021

Our house is split level and the floor level of the loft is about 1m lower at the front than at the back, which means there is a 1m high section of wall between the bedrooms at the back of the house and the loft (the lower half of the bedroom walls being between the front and back bedrooms). The loft floor is well insulated but this section of wall is not, and I think it contributes quite a bit of heat loss as those bedrooms get cold quite quickly.

In the loft, the wall is just very rough exposed brick. Can anyone advise what the best way to insulate it is? Space is no issue so it doesn't need to be compact like it would on an internal wall in a room, or in a cavity. I have considered just sticking up a load of standard loft insulation roll but think it might just slump or fall off. A board would be easier to put up but I think they are usually relatively thin and less effective than insulation roll?

Thanks

Post edited at 14:22
 Jack B 21 Mar 2021
In reply to Si dH:

What's access like? Do you have to get the insulation material through a small loft hatch?

 SouthernSteve 21 Mar 2021
In reply to Si dH:

If it doesn’t need to look pretty what about a kingspan like product. We have a ‘on a slope house’ and we used this on the wall of a bedroom (within the loft) whereas we used a sheep’s wool product for the floor of the same. We bought a copycat product which was available in relatively small panels, but bigger pieces would have been easier to fit, although not so easy in the car or to get through the door which is a half door in the room. 

Post edited at 14:28
In reply to Si dH:

Celotex

 gethin_allen 21 Mar 2021
In reply to Si dH:

I'd consider standard loft roll held in place with hooks in the wall and some fence wire at sensible intervals.

OP Si dH 21 Mar 2021
In reply to Jack B:

> What's access like? Do you have to get the insulation material through a small loft hatch?

Yee, sorry, should have mentioned - yes access is fairly tight.

 elsewhere 21 Mar 2021
In reply to Si dH:

https://www.screwfix.com/p/ybs-superquilt-multi-layer-reflective-foil-insul...

Looks easy to work with and get into the loft.

Post edited at 17:13
1
 MG 21 Mar 2021
In reply to Si dH:

Consider moisture movement too with whatever you do.

 pec 21 Mar 2021
In reply to Si dH:

I'd use cavity slab insulation (as used in cavity walls). It's a bit like loft roll insulation but has some structural integrity, i.e. it can support itself without flopping over but has some flexibility to get it into awkward places, unlike Kingspan type insulation (the rigid foam with a foil surface). A few wooden battens could be used to keep it in postion, e.g. vertical lengths of wood fixed to the ceiling joists at the bottom and the roof rafters at the top and positioned a few inches back from the wall to hold the insulation between them and the wall.

Something like this https://www.wickes.co.uk/Knauf-Insulation-Earthwool-Dritherm-Cavity-Slab-37...

Post edited at 20:29
 henwardian 21 Mar 2021
In reply to Longsufferingropeholder:

> Celotex

+1 for this.

if your loft access is 50cm wide, cut the sheets into strips 50cm wide and reassemble in the loft with some duck tape. Pretty straightforward.

There are a lot of ways to hold it in place, nothing fancy is needed as it's both light and rigid. Hard to decide what I might do myself without seeing a few photos (nails, screws, expanding foam, wedged in place, etc.)

It's a vertical wall so you need sometime rigid, anything like glass fibre of sheeps wool is a bad idea. Also insulation provided by something like celotex is a LOT more than a similar thickness of fibreglass/wool.

 Neil Williams 21 Mar 2021
In reply to Longsufferingropeholder:

> Celotex

I was going to suggest that as well.  Only problem with it is that it's basically polystyrene so does burn, so I'd give due consideration to whether that's a risk in that location or not, and if not it's probably the best bet.  Kingspan is another brand of basically the same stuff.

 olddirtydoggy 21 Mar 2021
In reply to Si dH:

Celotex/Kingspan are great insulators except in certain situations they can condensate quite badly. Ventilation is important in either fascia or soffit areas to allow the passage of air to circulate above them. I doubt the solid sheet insulation will work just against a short wall. Personally I favour the Knauf earthwool which can be bought cheaply at an insulation specialist. This stuff is fairly warm and breathes better

Is there any way you can fix it at the top of the wall where it meets the roof and drape it down?

30 years in the building trade.

 Brown 22 Mar 2021
In reply to Si dH:

Mineral wool is a good call. This comes in rolls or stiff battens ready to fix to walls. If you are insulating on the cold side of the brickwork you should avoid all interstitial condensation risk provided you don't do anything crazy like encase the outside of the mineral wool in a vcl.

Another positive of mineral wool is it is non flammable. The focus on flammable insulation has so far been restricted to high buildings and new flats but it may at some point to turn to standard domestic.

My professional insurance company will not let me specify flammable insulation on a domestic project regardless of building regulations. 

Mineral being the generic term for rockwool, earthwool etc

Post edited at 08:44
OP Si dH 22 Mar 2021
In reply to thread:

Thanks all. After doing some more research it seems that the celotex / kingspan option would work out quite expensive and require a lot of cutting, so I'm more unlined to using rockwool, earthwool etc type solutions.

Apart from the hook and chicken wire idea, has anyone got good suggestions for fixing insulation wool directly to an exposed and very old, rough brick wall?

To add - at the top and bottom of the vertical 1m high wall there is a horizontal section. It does not reach up to the roof. I could possibly just hang insulation down it unfixed if there was a way to attach it to other layers of preexisting wool type insulation on those horizontal sections.

Post edited at 13:03
 jkarran 22 Mar 2021
In reply to Si dH:

I'd just drape oversize pieces of thick loft wool type insulation over the step in the loft floor, it's cheap and easy where space isn't at a premium. With a bit of overlap top and bottom its own weight will keep it in place or you could add a baton or two to help. Whatever you put up you want to stop draughts between insulation and wall stripping heat away.

jk

 olddirtydoggy 23 Mar 2021
In reply to Si dH:

Get a length of roofing lat at around 2x1 inches in old sizes. Screw the lat to the timber at the top through the insulation roll and let if drape down. The Earthwool isn't itchy like the rockwool which sends my skin crazy. Always wear a mask.

 mwr72 23 Mar 2021
In reply to Si dH

> Apart from the hook and chicken wire idea, has anyone got good suggestions for fixing insulation wool directly to an exposed and very old, rough brick wall?

Buy a box of insulation spikes.


New Topic
This topic has been archived, and won't accept reply postings.
Loading Notifications...