Insulating Stone House

Discussion in 'Home energy' started by Poliver, Feb 7, 2017.

  1. Poliver

    Poliver New Member

    Hi all,

    I am investigating the amount of the task ahead of me and would like to hear from anyone on here who could help with links, advice or recommendations.

    The details:
    2-storey stone farmhouse, approx 100 years old.
    No DPC, as far as I can ascertain (perhaps a slate one, but definitely no modern one.
    Garden on one side is slightly higher and sloped towards house. No French drain. and no footpath on this gable (lawn comes right up to house). Damp on interior wall on this side.
    Garden wall connects to house on opposite corner and interior wall is damp there also. This wall was dry lined approx 25 years ago. God knows what lurks behind there now.
    External render/pebbledash is coming away from wall to approx 2M height.

    My questions:
    To prevent further damp, I am thinking that a french drain and footpath on one side. Disconnect stone garden wall and repair render with lime render on the other side. Is this a sensible start?

    To rectify the existing damp, what is the best thing to do? Rip out the dry-lining I assume and treat the stone wall directly with lime plaster?

    To insulate a house like this, what is recommended? There is a stove and an open fire both with back boilers and an oil boiler. Downstairs isn't too bad but upstairs rooms are very cold on cold nights. Attic is pretty well insulated. I have read that these walls need to breathe but we need to stay warm without burning oil/coal constantly. Would retrofitted underfloor heating with geothermal be beneficial?

    I'm just starting down this rabbithole now so any advice or resources in advance would be welcome.

  2. PaddyBloggit

    PaddyBloggit Frequent Poster

    I bought a similar house as a holiday home a few years ago. I stripped all plaster (inside and out) - cleaned back the stone.

    Outside was re-plastered. Insulated slab boards nailed (special nails - drilled and hammered into stone, also used adhesive).

    Joints were taped and then skim coated.

    No sign of damp since.

    I use a backboiler stove to heat the house. It's running 7 rads. Upstairs and downstairs zoned separately and both run on separate pumps.

    Once downstairs is hot, upstairs is allowed to kick in. House is warm and comfortable.
  3. Poliver

    Poliver New Member

    Thank you for the prompt reply.

    It's the piece about the insulated panels that have me confused.
    From what I understand, the walls being damp is a problem that obviously needs to be resolved by letting them dry out.
    Those insulated panels apparently prevent this and so the walls stay damp, but are just hidden by the panels.
    Maybe there are breathable ones available, I don't know.
    Did you use lime plaster or cement plaster inside? Same question for the render outside.

    Does your place have those high 'vaulted' type ceilings upstairs that make the rooms a pig to heat?
  4. PaddyBloggit

    PaddyBloggit Frequent Poster

    My walls were just stone built, about 2 feet wide and no dpc.

    The house is around 100 years old.

    I did nothing special. I just hacked off all the plaster and I use a special narrow hammer I got in Aldi to clean all stone back.

    Outside, any loose stone was removed and holes filled with mortar. Plasterer scudded the walls and they got two coats of a standard mortar mix.

    Inside, I did the same. I didn't use a metal frame. Walls were straight enough so insulated plaster board was fixed on with nails & adhesive. Some have cavity behind them in areas as the plaster boards were leveled with each other. Once cleaned and allowed to dry out I didn't see anymore signs of damp. Internally, the plaster was just standard plaster. I didn't use any lime. All fine and the job has been done 3 years now. I also used insulated boards on the ceiling .... well worth doing as I feel it definitely helps keep the house warm.

    I have rolls of insulation to lay in the attic yet but reckon heat retention will only get better.

    I rebuilt the chimney internally (didn't touch the outside of the gable). It was too big and it gave me back room in the house.

    I also redid the roof. Timbers weren't great. I raised the walls by 2 feet, which gave great room in the upstairs rooms.

    No vaulted ceilings here. By raising the walls 2 feet I was able to raise the upstairs floor a little, giving me more ceiling height downstairs. I have exposed rafters downstairs and insulated ceiling boards upstairs.