Victorian Timber Frame Insulation Options

[Luke1]

I've just bought a late 1800's semi detached property. It is of solid brick construction on the ground floor, with a tile hung timber frame 1st floor.

The house is in need of full modernisation, some of the lath and plaster has significant cracks that were hidden by lining paper, and it doesn't even have central heating!

 

So far I've removed the lath and plaster (what an awfully dusty job that is) and now I'm looking at my options to insulate.

 

On the 1st floor I have a tile hung facade with a felt backing all attached to 4x2 stud work.

I plan to insulate with 75mm celotex whilst leaving a 25mm airgap on the cold side, then fix a vapour control membrane / vapour barrier and then plasterboard & plaster over the top.

I'm going to limit sockets etc to the external walls as much as possible to help prevent interstitial condensation through penetrating the membrane.

Does this sound logical?

 

On the ground floor I have a solid brick wall. It currently has the studwork from the original lath & plaster. Unfortunately there is not much more than 50mmof cavity space therefore I am thinking of using insulated plasterboard on the external walls. Is this what others would do? Would I need a vapour control layer?

 

Finally, do I need to notify or inform building control about these works? 

 

Thanks in advance for any advice!

[Roger440]

6 hours ago, Luke1 said:

I've just bought a late 1800's semi detached property. It is of solid brick construction on the ground floor, with a tile hung timber frame 1st floor.

The house is in need of full modernisation, some of the lath and plaster has significant cracks that were hidden by lining paper, and it doesn't even have central heating!

 

So far I've removed the lath and plaster (what an awfully dusty job that is) and now I'm looking at my options to insulate.

 

On the 1st floor I have a tile hung facade with a felt backing all attached to 4x2 stud work.

I plan to insulate with 75mm celotex whilst leaving a 25mm airgap on the cold side, then fix a vapour control membrane / vapour barrier and then plasterboard & plaster over the top.

I'm going to limit sockets etc to the external walls as much as possible to help prevent interstitial condensation through penetrating the membrane.

Does this sound logical?

 

On the ground floor I have a solid brick wall. It currently has the studwork from the original lath & plaster. Unfortunately there is not much more than 50mmof cavity space therefore I am thinking of using insulated plasterboard on the external walls. Is this what others would do? Would I need a vapour control layer?

 

Finally, do I need to notify or inform building control about these works? 

 

Thanks in advance for any advice!

 

There has been a flurry of posts on here about older houses.

 

Stop, and get educated on it first. Insulated plaster board, celotex etc. No, no no. Not in an 1800;s house.

 

Seriously, peruse, at length, these 4 sites before you do work you later find needs ripping out.

 

One word. Breathability.

 

https://www.heritage-house.org/

https://www.mikewye.co.uk/

https://www.lime.org.uk/

https://www.periodproperty.co.uk/forum/viewforum.php?f=1

[Luke1]

Thanks Roger for the links. I hadn't come across a couple of these before.

 

I'll continue to read up and understand how to move on with the property. After all I am hopefully just here as a custodian to the property. 

Having said that, I believe it is important to modernise the property and with the technology available today I would hope that I can do this with modern materials.

[Iceverge]

On 20/01/2021 at 20:44, Luke1 said:

Having said that, I believe it is important to modernise the property and with the technology available today I would hope that I can do this with modern materials

 

Proceed with care or you could end up with a worse building than what you started with. 

 

Fundamentally you want to prevent anything getting wet or even worse wet and cold because it will fall apart in shortish order 

 

Internal insulation is making the structure cold and unless you install a perfect vapour barrier (almost impossible on a retrofit) it'll get damp. 

 

Ideally external insulation would be the best but if you can't do that a considered later of breathable insulation between the studs (woodfiber being one) covered by a breathable layer of lime plaster and breathable lime paint will keep you warm and preserve the house for future generations. 

 

 

[Luke1]

On 22/01/2021 at 22:02, Iceverge said:

 

Proceed with care or you could end up with a worse building than what you started with. 

 

Fundamentally you want to prevent anything getting wet or even worse wet and cold because it will fall apart in shortish order 

 

Internal insulation is making the structure cold and unless you install a perfect vapour barrier (almost impossible on a retrofit) it'll get damp. 

 

Ideally external insulation would be the best but if you can't do that a considered later of breathable insulation between the studs (woodfiber being one) covered by a breathable layer of lime plaster and breathable lime paint will keep you warm and preserve the house for future generations. 

 

 

 

 

Thanks for your posts guys.

I went away and did a fair bit of research.

I've now gone down a fully breathable route with Sheeps Wool insulation, wood fibre boards & lime plaster.

Its costing a small fortune, however I have no doubt that it is the right method for the house. 

 

Now that I have much of the structure un-covered I've only found one rotten joist and that was due to someone previously blocking up a vent with some paving slabs to reduce the step up to the door.

It was interesting to find the underside of the floor boards dripping wet, which clearly shows how important under floor ventilation is! 

[Iceverge]

Good stuff.

 

To quote the Americans:

 

"If it can't dry its gonna die!"

 

Do you have a ventilation strategy for dealing with moisture/ CO2 and VOC's generated inside the house? 

[Luke1]

On 03/03/2021 at 09:56, Iceverge said:

Good stuff.

 

To quote the Americans:

 

"If it can't dry its gonna die!"

 

Do you have a ventilation strategy for dealing with moisture/ CO2 and VOC's generated inside the house? 

The house is far from air tight so I do not believe further ventilation will be necessary unless I can improve the airtightness first!

 

Hopefully VOCs will be minimised where I am using natural products as far as possible.