Exposed stone walls in a barn conversion

[Geoffrey]

Good morning,
 

I am formulating plans for the renovation of a small steading near Inverness.   It has been abandoned for many decades. The walls are made of typical irregular stone blocks and chunks.  Really charming.  Even though it just has a weathered corrugated roof there is little damp.   Our ancestors knew how to build!

 

I want to keep the walls exposed internally.  It is just one storey.   I plan to repoint using lime mortar, other than that my wish is to keep the walls visible.  

 

I have not submitted a planning application yet. I know these days planners are concerned with insulation. I am fully prepared to over-insulate the roof et cetera to mitigate the bare walls. I just wondered if any members had approached Scottish planners with a similar design requirement.  If so I would hugely appreciate knowing any tips and hints.
 

Thank you.  

 

[ProDave]

Hi and welcome.  Not far from me then (I'm 20 miles north of Inverness)

 

A big problem with a lot of old steadings is the almost complete lack of foundations.  Assuming you will want to dig out the floor t insulate it, be careful.

 

Very few are left as bare stone, most line and insulate the inside.  How about just leaving one stone feature wall.

 

Sounds like an interesting project.

[Geoffrey]

Hello,

 

Thank you for your welcome and for your advice. Yes I know it will not be straightforward…  It is an exciting project.  I’m sure I shall be posting regularly on here.  
 

Yes I will be digging out the floor for installation and UFH.  I currently live in a modern home with perfectly smooth plastered walls at ninety degrees, and I now want to go entirely in the opposite direction.  That’s a good point about not keeping all walls exposed.  That could be a planning compromise.  
 

Thanks
 

 

[Ferdinand]

if you have an internal division, you could use that as the feature wall, which would not compromise your fabric.

 

Or put a lead to orangery or extension of some sort on the back of your feature wall to make it internal.

 

Ferdinand

[scottishjohn]

expect  extremly high heating costs and possible damp problems in walls 

lime mortar does allow moisture to evaporate out ,but also allows it to get in from outside or up from the ground below (rising damp)-

 so trying to have bare wallls on a house with no damp proof course or foundations or insulation  is a non starter

  ufh seems a bit of a waste of time  ,if reasonable heating costs is in your mind .

not sure how you will keep planning happy with no insulation 

 

Edited March 25, 2020 by scottishjohn

[Geoffrey]

Thank you for your comments.  Lots to think about. 

[Cpd]

you could look at external wall insulation that then linked into a warm roof ? If the walls have footings you could look at digging in the exterior insulation as deep as possible to help minimise heat loss, your still going to have huge thermal bridge at the bace of the walls that will make UFH a non starter and these cold spots will be a perfect place for condensation and then mould.....  I wanted to keep my stone walls inside as they were lovely but in the end the only way to keep the heat in And not have condensation problems is to line them internally. I concentrated on making the outside walls the feature through carful pointing. 

[scottishjohn]

I,ve been plotting same problem with my house 

the favoured solutiuon by all --If i want to keep exterior walls is to dig out floor

spray all internal walls with closed cell foam min 30mm --that water proofs it and build TF inside with new floor slab.

OR 

most popular  suggestion from architect and buulders-as it should be easy to be accurate with costings

flatten it -rebuild how ever I like -then use granite as exterior cladding

Kirmabreck House old (9).pdf

Edited March 25, 2020 by scottishjohn

[Geoffrey]

2 hours ago, Cpd said:

you could look at external wall insulation that then linked into a warm roof ? If the walls have footings you could look at digging in the exterior insulation as deep as possible to help minimise heat loss, your still going to have huge thermal bridge at the bace of the walls that will make UFH a non starter and these cold spots will be a perfect place for condensation and then mould.....  I wanted to keep my stone walls inside as they were lovely but in the end the only way to keep the heat in And not have condensation problems is to line them internally. I concentrated on making the outside walls the feature through carful pointing. 

Thank you for your valid thoughts. Very helpful.  
 

Your house looks charming.  I love the row of windows under the eaves.  

[Geoffrey]

1 hour ago, scottishjohn said:

I,ve been plotting same problem with my house 

the favoured solutiuon by all --If i want to keep exterior walls is to dig out floor

spray all internal walls with closed cell foam min 30mm --that water proofs it and build TF inside with new floor slab.

OR 

most popular  suggestion from architect and buulders-as it should be easy to be accurate with costings

flatten it -rebuild how ever I like -then use granite as exterior cladding

Kirmabreck House old (9).pdf 458.74 kB · 2 downloads

Thank you.  The first option makes sense.  
 

Second option is a bit drastic.  I’m too much of a romantic for that.   Your place looks impressive, and must generate its own challenges.  Mine is about of twentieth of the size.  
 

 

[scottishjohn]

2 minutes ago, Geoffrey said:

Thank you.  The first option makes sense.  
 

Second option is a bit drastic.  I’m too much of a romantic for that.   Your place looks impressive, and must generate its own challenges.  Mine is about of twentieth of the size.  
 

 

closed cell foam is quite a popular way in US to waterproof basements from the outside  instead of tanking etc and internal drainge systems

 painting outside of walls -should then something that can let the moisture in the wall go outwards ,not seal it in 

Edited March 25, 2020 by scottishjohn

[Cpd]

Put some photos up, if for no one else I also love the charm of old buildings and just keep on charging into these projects...... lost a fortune and most of my  sanity...... the triangle window are the only specific local architectural feature in old buildings round here and I wanted  to add some when I was repairing the walls, they are not actually windows in this instant, but sudo window with mirrors and lights..... just a bit of fun. Normally they would be low down and in more agricultural style buildings but as I said it was just a nod to there existence as most of the old buildings get knocked down and this heritage feature  is lost...... 

[Geoffrey]

2 hours ago, scottishjohn said:

closed cell foam is quite a popular way in US to waterproof basements from the outside  instead of tanking etc and internal drainge systems

 painting outside of walls -should then something that can let the moisture in the wall go outwards ,not seal it in 

Thank you. I’ll look into that

[scottishjohn]

1 minute ago, Geoffrey said:

Thank you. I’ll look into that

going rates I have been quoted is about £35 sqm--so not cheap --but it is also has high insulation value as well

Edited March 25, 2020 by scottishjohn

[Geoffrey]

1 minute ago, scottishjohn said:

going rates I have been quoted is about £35 sqm--so not cheap --

Hmmm.  Yes.  I’m 88 sqm.   If it gives me the finished effect that I want, I’ll save on lining, skimming, painting etc

[scottishjohn]

Just now, Geoffrey said:

Hmmm.  Yes.  I’m 88 sqm.   If it gives me the finished effect that I want, I’ll save on lining, skimming, painting etc

you still going to have to line or build stud walls + PB and interior finish 

,but price up a proper tanking solution and it will not look that exspensive 

[Geoffrey]

2 minutes ago, scottishjohn said:

you still going to have to line or build stud walls + PB and interior finish 

,but price up a proper tanking solution and it will not look that exspensive 

Oh I see. Thanks.   I’m still resistant to having inner stud work.  

[Iceverge]

Hi Geoffrey, 

 

How thick are the walls? I had a quick peruse of this paper.

 

https://www.historicenvironment.scot/archives-and-research/publications/publication/?publicationId=16d0f7f7-44c4-4670-a96b-a59400bcdc91

 

They measured old stone and rubble walls in situ .  I didn't read too deeply but it suggests a conductivity of about 0.72 W/mK  although they varied to about double this ( I suspect for walls with higher levels of dampness).

 

If you were confident your walls could be kept dry and were say 600mm thick could you expect a U value of 1.2W/m2 K. Well short of the regs but maybe with very high levels of floor and roof insulation, good air-tightness and triple glazed windows you could create a very comfortable home with your exposed stone walls. 

 

Failing that, externally insulating would work nicely and allow you to run all your services from the outside-in avoiding conduit or pipes showing inside. 

 

If there was no proper footings, insulation wings as shown joining to the external insulation would do the trick. 

 

Jonathan 

 

 

 

 

 

 

 

 

 

 

 

[Cpd]

The “wings” is the word I should have used when I talked about digging in the external insulation. 

[Iceverge]

No idea if that’s the right term. Just seemed appropriate. Beautiful house BTW

[Geoffrey]

Hello Jonathan,

 

Thank you very much indeed for your detailed reply and explanation. That has given me a lot of hope. I am very grateful.

 

Best,

Geoffrey