Barn Conversion South of Bristol

[Sam Barn]

Hello everybody,

I'm in the process of converting an old limestone barn just south of Bristol.  Its a single storey old cow barn about 20 x 5m in size so not massive, but enough for my fiancee and me to live in.  Walls are 450mm wide random limestone made from the local stone.  I have a small budget, but obviously my labour is free.

 

Up to now I have connected gas, water, electric and sewerage, luckily it was in a village so not too far to bring in all these services.  I have also put a new roof on it, I have built three new trusses and put in a series of purlins, as the existing roof was pretty rotten and made from softwood that wasn't original.  I have also put in the structual concrete floor.  My plan is to have the timber exposed in the ceiling, internal part of the external walls studded out and plaster boarded, while leaving internal partition walls as stone to try and keep some of the history inside.

 

The photo should show the inside of the barns with trusses etc.  I've just found this forum, which might of helped me with the bits I've done up until now, but at least I've found it now.  I'm currently in the process of put down a new floor and will start on the internal walls when that is finished.

 

My biggest issue is what to do with the exterior walls, I have spent the last year changing my mind and generally just worrying about what to do with them.  It would be great to get some advice on this, although I appreciate there is probably no right or wrong answer on what to do.  Current plan is:

 

450mm Limestone walls re-pointed with lime externally

Vapour membrane (I was just thinking of continuing the DPM from under the floor and joining into the vapour barrier on the ceiling)

89mm stud wall fixed to the floor and rafters, filled with either PIR or rockwool

vapour check barrier

service void (25mm battens)

plasterboard and skim

 

I should mention that the walls are dry at the moment and drainage is good onsite. The walls are also thicker at the bottom then top so there will be a 20-100mm air gap behind the stud work.  When putting in the floor I installed an eggcup (Delta PT type) membrane around the edge to allow any condensation to drain down the inside of the wall to a perforated pipe I installed around the edge of the barn.  The drawing attached shows my current plan for the floor/wall/roof.

 

I'm really looking forward to hearing people thoughts on this.

Thanks Sam

 

Wall_detail.bmp

[ToughButterCup]

First, a warm welcome.

You have a brilliant little project , and if the photo is to be believed, a demanding dog too.  So, that makes two clubs of which we are both members.

 

27 minutes ago, Sam Barn said:

[...]

I have a small budget, but obviously my labour is free.

[...]

My biggest issue is what to do with the exterior walls,

[...]

 

Joined the small budget club too eh? And if your labour really is free, pop up to J33 on the M6 and I'll be happy to reinforce your delusion. I'll pay yer mileage.

Exterior walls - I don't really have a technical answer, but I would start by looking at what others in your area have done / are doing. 

 

Like I say M6, junction 33, 0900 sharp tomorrow morning.

[Sam Barn]

Haha, I guess its not a good idea to advertise free labour.  Yes my Sprocker Spaniel keeps me company onsite, but has developed a keen sense of smell for pencils and will crunch any when found!  He also likes tape measures and ear defenders, so will probably end up doing my measuring and marking by eye.

[Mr Punter]

Hello Sam and welcome

 

With vapour control layers the convention is to place them on the warm side of the insulation. You should maybe do away with the membrane against the wall as it may trap any moisture which would be better to diffuse out through the stonework. Just make sure the VCL over the studwork is properly fitted, lapped and sealed. Regarding insulation, Rockwool may be difficult to keep in place if it just open studwork, whereas pir can be foamed in securely.

[TheMitchells]

Fab barn - pics of dog please too.  looking forward to hearing all about the renovation.  Cant help with any advice, sorry, unless its gardening related but will enjoy ?seeing how you get on. Welcome to the best advice forum on the web!

 

[Ferdinand]

Welcome @Sam Barn. looks like a good project.

 

I grew up in a restored small Manor House with walls that thick, though rubble fill. Our renovation took more than 20 years ?.

 

My initial comments:

 

1 - I would avoid the rockwool for 2 reasons. In a narrow property it is a little bulky, but if they get in it will be loved by vermin. What is your strategy for Roland and his friends ? That required gap under the old foundations in the detail is a slight alarm bell for me wrt to tunnelling under the slab,  but it is not an area where I am very knowledgeable. I suspect they would access your inside/outside wall gap from the top, though.

 

In ours we used to get rats scrambling about inside the walls. How will you protect that gap behind your inner wall?

 

2 - Is that insulation enough? It is close to Building Regs minimum, and I question that for such a long, and quite narrow, building.

 

Perhaps some thermal modelling to determine the value in adding more insulation to your walls? PErhaps PIR both ways, with the inner side of the outer layer taped for more airtightness?

 

3 - How are you ventilating? 

 

Ferdinand

 

[scottishjohn]

If its lime mortar ,will it need air gap --

fill in the gap behind studding with spray foam  --the no where for roland and friends to be

plus its  more insulation  + wall moisture  should go outwards as it will be sealed by foam   ??

something to consider  maybe  ?

[willbish]

Hello mate, good to see you've finally signed up

 

Mods, ill take the commission for this one!

[Cpd]

Hello and welcome, looks like a great project

my cottage looked a bit like this when I ripped it all apart........

My downstairs wall build up will be 

 

700mm stone wall with rubble in the middle 

Ventilation gap between old wall and studwork 20-70mm 

50mm studwork attached to wall and infilled with pir

70mm pir over front of stud work 

Possible service void but I’m thinking of running cables in conduit on the surface (barn style !) 

12mm OSB it’s a small cottage 10x5 the additional osb layer is to allow me to fix anything anywhere ! 

12mm plasterboard  

skim 



 

[Geoffrey]

Hello Sam,

 

I know your post was a while ago, but I’ve just joined this forum as I am about to start a very similar project to you, which is exciting.  I hope house is now complete and that it went according to plan, without too many nasty surprises   I like your plan in putting LED lights at the top of the wall. I just wondered what you did with the wall covering. I have a very romantic idea of keeping the stone exposed.   I’m trying to look at ways of doing this but the feedback so far has not been encouraging.
 

Best wishes,

Geoffrey