Solid Wall Insulation

Nameless1

If an old mill (for ex.) has 600mm solid walls, is there any way of insulating the external walls, apart from dryling internally? This would take up a lot of space and showing the stone rather than covering it up would be a nice feature.

The walls are solid stone and external insulation would not suit as the mill is protected.

AckwelFoley

Im not aware of any way around this.

I would however insulate the ceiling area, as this is where perhaps most of the heat is lost.

Mellor

Nameless1 wrote: »

If an old mill (for ex.) has 600mm solid walls, is there any way of insulating the external walls, apart from dryling internally? This would take up a lot of space and showing the stone rather than covering it up would be a nice feature.

The walls are solid stone and external insulation would not suit as the mill is protected.

To be brief than answer is no.
The options are internal or external insulation, if you rule out both of them them there is no option really.

sinnerboy

suggest you erect free standing stud frames internally and insulate them . this follows conservation principle of "reversibility" i.e. the works can be reversed leaving the historic structure undamaged .

"face" the studs with a breather membrane towards the external , and to the internal use an polythene vapour check . then batten out for a services cavity , slab over with foilbacked plasterboard .

I'd prefer to be warm , not facing stone wall .........

sydthebeat

If you rendered internally with about 40-50mm of hemp / lime concrete... you would probably be looking at a wall with a u value of about 1.0... now this may appear not satisfactory at first, but there are a few points to remember.

Due to the massiveness of the walls the heat loss time is minimized. These wall will absorb and retain solar heat in the daytime and release it at night. Usually with walls this thick the release is slow so the wall will always have some heat retained, therefore the performance is increased.

Dont use any non breathable material anywhere in the upgrading.

If you want to leave stone facing visible internally, i would ensure its on south facing walls only. I would render the other three orientations internally.

The quality of living in a building like that has to be balanced out with the 'running cost'. You will never get it truly 'energy efficient' but aim to get it as best as you can.

sinnerboy

Actually ( penny dropping ) - if your building is a protected structure you ought to have a conservation architect overseeing the works .....and the works ought to be agreed IN ADVANCE with the LA conservation officer . Be careful this does not end in tears

Mellor

Actually actualy, if the mill is protected you may not be able to alter the interior anyway.
Protected structures are be completely protected or simple an element of internal or external. Check your LA development plan

sinnerboy

Can be done Mellor , as I suggested in a reversible manner . BUT this must be done by agreement - in the form of a planning application . Or at the least a Section 5 declaration on exempt development.

I know of a case where , a "celebrity" client found an historic fireplace was not to his liking . He was permitted , by negotation with CO , to mdf over it and onto that cladding impose a style more to his liking .

bottom line OP - proceed with great care

Mellor

sinnerboy wrote: »

Can be done Mellor , as I suggested in a reversible manner . BUT this must be done by agreement - in the form of a planning application . Or at the least a Section 5 declaration on exempt development.

I meant you can't go ahead and just do it. You could if the internal was not protected.
If you get "agreement - in the form of a planning application", you can do what ever you want. Reversable or not.

Nameless1

sydthebeat wrote: »

If you rendered internally with about 40-50mm of hemp / lime concrete... you would probably be looking at a wall with a u value of about 1.0... now this may appear not satisfactory at first, but there are a few points to remember.

Due to the massiveness of the walls the heat loss time is minimized. These wall will absorb and retain solar heat in the daytime and release it at night. Usually with walls this thick the release is slow so the wall will always have some heat retained, therefore the performance is increased.

Dont use any non breathable material anywhere in the upgrading.

If you want to leave stone facing visible internally, i would ensure its on south facing walls only. I would render the other three orientations internally.

The quality of living in a building like that has to be balanced out with the 'running cost'. You will never get it truly 'energy efficient' but aim to get it as best as you can.

Yea I see what you mean. In another development I found that 250mm solid stone walls where insulated internally with 110mm insulated plasterboard slabs - this takes up a lot of space and the mill is currently only 4500mm wide.
40-50mm of hemp and lime seems more reasonable