Old Cottage Renovation

AKK

Hi guys - calling on your expertise here!

1. Family members currently renovating a traditional old cottage and they want to keep as many original features as possible. The cottage has thick stone walls (about 2 ft or so in depth). At the moment the exterior of the house is plastered but the intention is to remove that to expose the natural stone. Does anyone know the best type of pointing for this stonework?

2. Moving indoors, the intention is to slab the 'inside' of the external walls (hope that's clear). However the finish on those walls currently is quite 'rough', as in it's not a smooth modern finish. Is it possible to get this finish over plaster board? (The idea of the plasterboard is to insulate). Can hemp plaster be applied over plasterboard and would this give the desired finish?

3. Upwards to the ceiling! The roof is in good condition but there is no felt under the slates. The slates are placed directly onto wooden batons. Is it necessary to re-roof the house in order to re-'felt' it or are there "sealing" products available that could be applied to the underside of the slate?

4. At the moment, the fireplace is a grate with an 'open' chimney (as in no flue liner inside). Is there an easy way to install a flue-liner??! Is a flue-liner necessary?

We'd be very grateful for any suggestions/comments anyone might have.
Thanks.

RKQ

1. Lime mortar. Do not use cement. Lime render is an important water barrier on stone buildings. Depending on the quality of stonework you might have to re-render with lime.
You could insulate externally and expose the stone internally!

2. Rough plaster can be done on slabs. IMO maintain a cavity between the stonewalls and the insulated dry-lining - especially if removing external render.

3. Certain "foam" claims to work in your situation - ensure it has a IAB cert before using. IMO felt is important as it it not unusual to loose slates on an old building :eek:. At least the felt will keep the rain out.
Why no insulate between & over the existing rafters? Breather Felt, counter batten and re-slate.

4. Wide chimneys can be retro fitted with a flue. Usually done if fire is made smaller or smoke leaks from breast.

Slig

Removing the plaster outside might not be the most practical solution. many such stone walls were built with the intention of being plastered so the stonework is probably crap underneath. Your also leaving yourself exposed to water ingress.
I assume that you are intending to use insualtion backed plasterboard. This combined with the now bare stone walls will only hide any damp that passes throught the walls. You are also removing the thermal mass of the building but improving the insulation. I dont see why you cannot get an uneven finish on the slabs.

If possible get a survey of the roof structure done, if the timbers are rotten then replace and felt over with a breathable felt. If its not broken then dont fix it. When the job needs doing then do it right. Insulate between the ceiling slabs not the rafters, if there is no felt then your roof space may need lots of ventilation to keep it dry.

There are a couple of retrofit chimney liners available, A stainless steel flue if you are going to use a stove or Vermiculite can be used to create a flue.

There are afew companies that do it but basically they shove a deflated tube into the chimney, block the bottom and fill it with vermiculite. Then they inflate the tube which compacts the vermiculite around it creating a flue.

AKK

RKQ wrote: »

1. Lime mortar. Do not use cement. Lime render is an important water barrier on stone buildings. Depending on the quality of stonework you might have to re-render with lime.
You could insulate externally and expose the stone internally!

2. Rough plaster can be done on slabs. IMO maintain a cavity between the stonewalls and the insulated dry-lining - especially if removing external render.

3. Certain "foam" claims to work in your situation - ensure it has a IAB cert before using. IMO felt is important as it it not unusual to loose slates on an old building :eek:. At least the felt will keep the rain out.
Why no insulate between & over the existing rafters? Breather Felt, counter batten and re-slate.

4. Wide chimneys can be retro fitted with a flue. Usually done if fire is made smaller or smoke leaks from breast.

That's great advice RKQ. Thanks a million. Just have a couple of more queries if you're willing?!

In relation to point 2 - rough plaster over slabs - is there a particular one you could recommend? Is hemp the way to go?

In relation to point 4 - the chimney appears quite wide, but the grate area is just your standard size surrounded by natural stone - would that stone have to be knocked away (and then replaced!) in order to install the flue? We've already exposed the entire stone wall in which the chimney 'sits' and towards the ceiling there's a kind of blackish/sooty/dark stain on the stone. We wonder if this could be caused by rain coming down the chimney and 'seeping' through? Since exposing the stone, we've lit a number of fires which don't appear to have worsened the stain or anything so we're not sure if it's smoke leaking from the breast. Could discolouration on the chimney breast be caused by not having sufficient lead-flashing on the chimney?
Also, there is currently a great draft up the chimney which is inclined to draw the blaze upwards. Would a flue improve this?

Thanks again for your comments so far.

AKK

Slig,

Thanks for that. If you know of any Irish companies that do the Vermiculite could you PM me the details please?

(The house is based in the Kerry area).

While we'd like to expose the stone on the exterior, it's not absolutely crucial (in fact some members involved in the project would rather keep it covered and whitewash!) and we will yield to a more practical solution. Any suggestions regardng insulating the outside and re-applying a rough render for a traditional finish?

Slig

Again I'm not really sure that external insulation is a great solution for a retrofit either (although this is where it started). Old structures need to breath so sealing it off with polystyrene doesnt help.
A lime rendered, whitewashed cottage will look alot better than an exposed stone one.

With old buildings like this it is actually better to stick with traditional methods.

MicktheMan

AKK,
what type of ceiling is there between the attic and rooms underneath? I have surveyed a lot of cottages and find in nearly all cases that the old timber latted ceilings on their own perform very poorly from an air tightness point of view.

AKK

MicktheMan wrote: »

AKK,
what type of ceiling is there between the attic and rooms underneath? I have surveyed a lot of cottages and find in nearly all cases that the old timber latted ceilings on their own perform very poorly from an air tightness point of view.

MicktheMan - apologies for the delay in responding. Basically the ceiling was slabbed - that has all been removed though so basically at the moment we just have slates on the wooden batons. As far as I'm aware, the plan is to re-slab that - there was talk about a timber latted ceiling but as in your post, we have concerns about draughts.