Building a workshop in an old stone built barn

[mikej460]

Interesting - so, build the stud wall on the back wall, where alter damp is, for shelving etc, while keeping the front wall as is

No not that, I'm assuming here that your damp could be fixed by the french drain and new floor. What I mean is that you could preserve the main, more attractive stone walls and use another wall or part wall for storage using internal stud work.

Another point to support roof insulation is that cold damp air condenses on colder metal or cement roof sheets and drips like rain all over your workshop. By insulating and sheathing with osb you can prevent this.

 

[David66]

No not that, I'm assuming here that your damp could be fixed by the french drain and new floor. What I mean is that you could preserve the main, more attractive stone walls and use another wall or part wall for storage using internal stud work.

Another point to support roof insulation is that cold damp air condenses on colder metal or cement roof sheets and drips like rain all over your workshop. By insulating and sheathing with osb you can prevent this.

Ah, OK.

TBH, digging out the back wall would be tricky. The main access track is right behind the shed, and about 4' higher than the floor of the shed. On the other side of the track there's rock. I suspect that digging out the wall would mean repositioning the track, which would mean digging out all the rock. And getting a digger in there (4km along a very narrow and steep 4x4 track) wouldn't be cheap!

 

[mikej460]

Ah, OK.

TBH, digging out the back wall would be tricky. The main access track is right behind the shed, and about 4' higher than the floor of the shed. On the other side of the track there's rock. I suspect that digging out the wall would mean repositioning the track, which would mean digging out all the rock. And getting a digger in there (4km along a very narrow and steep 4x4 track) wouldn't be cheap!

Wow, ok then unless you can dig a 6ft deep trench down the back of the wall and back fill with pea shingle and a DPM between the shingle and the wall you are a bit stuck. You could still go ahead with phase 1 as I laid out but be prepared for phase 2 - building the internal wall.

 

[David66]

Wow, ok then unless you can dig a 6ft deep trench down the back of the wall and back fill with pea shingle and a DPM between the shingle and the wall you are a bit stuck. You could still go ahead with phase 1 as I laid out but be prepared for phase 2 - building the internal wall.

Is that 6' below floor level? How wide would it need to be?

 

[mikej460]

No, assuming you can't move the road dig 4 feet down plus 2 feet to take water below floor level, I'd make it 450mm across. Bear in mind that a 6ft trench is a potential death trap so use experts to dig this for you. Line the trench with a Geotextile sheet in a U shape with a flap lid to stop soil working it's way in, lay the a DPM down against the wall or get a plasterer or builder to trowel on tanking to the outside of the wall which, if done properly, is very effective and often used to dry out old cellars for example). You could then back fill with a layer of soil to restore the track as long as you don't go above the tanking. I'd encourage you to research this and talk to a couple of good builders.

 

[David66]

No, assuming you can't move the road dig 4 feet down plus 2 feet to take water below floor level, I'd make it 450mm across. Bear in mind that a 6ft trench is a potential death trap so use experts to dig this for you. Line the trench with a Geotextile sheet in a U shape with a flap lid to stop soil working it's way in, lay the a DPM down against the wall or get a plasterer or builder to trowel on tanking to the outside of the wall which, if done properly, is very effective and often used to dry out old cellars for example). You could then back fill with a layer of soil to restore the track as long as you don't go above the tanking. I'd encourage you to research this and talk to a couple of good builders.

Thanks for all your advice. Appreciate you taking the time to explain in such detail.

I don't think digging down the back of the wall is an option - getting somebody to do that would be expensive, even if I could find somebody (almost impossible in that location). The internal wall solution will be cheaper and easier, as I can (hopefully) do it myself. Only down side I can see (other than additional time and materials), is I'll lose some internal space, around 250mm on each wall (50mm gap to the first wall, 50mm for that wall, 50mm gap to the second wall, 75mm for that wall, plus another 11mm for the OSB).

Not a disaster!

 

[mikej460]

Thanks for all your advice. Appreciate you taking the time to explain in such detail.

I don't think digging down the back of the wall is an option - getting somebody to do that would be expensive, even if I could find somebody (almost impossible in that location). The internal wall solution will be cheaper and easier, as I can (hopefully) do it myself. Only down side I can see (other than additional time and materials), is I'll lose some internal space, around 250mm on each wall (50mm gap to the first wall, 50mm for that wall, 50mm gap to the second wall, 75mm for that wall, plus another 11mm for the OSB).

Not a disaster!

ok but you don't need some of the gaps you listed only between the 1st (batten/housewrap) and the stud wall. so 50mm wall to wrap, 75mm studwork, 11mm OSB3 so 136mm on each wall. Apols if I confused you, I'm trying to explain a timber frame workshop build working backwards!

 

[MCTWoodwork]

Great project, I did something similar in an milking shed where we used to live.. I laid a DPM then a hand mixed concrete floor to level the floor with a builder friend. I also drilled the wall (every 300mm at about a foot high) and filled with a liquid DPM to stop rising damp along with the sheet DPM (Under the concrete). It's not too expensive stuff but worth it. Then as Mike said, I created an internal "room" as he described with studs and noggins and insulation and filled any gaps with expanding foam leaving a small gap on the OSB from floor level to allow it to breathe. Good luck!

 

[MCTWoodwork]

Ps - I was referring to the gap between the concrete floor and walls... You obviously won't do that if you create a floating floor. Anyway... Ageing, good luck and sounds like you will have a great space to make pretty things out of wood and lots of sawdust...

 

[Adam W.]

@David66 It looks like a massive job and making a shed like that dry enough to keep tools in is going to take a lot of work.

We lived on a very steep slope in the Mendips a while back and I picked up an old 10' garden shed for free to use as the bathroom and then my workshop.

That's what I would do in your case and leave the stone building to the bats and spiders.

 

[David66]

Another point to support roof insulation is that cold damp air condenses on colder metal or cement roof sheets and drips like rain all over your workshop. By insulating and sheathing with osb you can prevent this.

One thing I didn't mention last night - there are no windows in the shed - all the natural light comes in via transparent panels in the roof (not roof windows, just clear corrugated plastic sheets). So, if I insulate and sheet the roof, there will be large gaps for these sheets - still worth it?

 

[David66]

@David66 It looks like a massive job and making a shed like that dry enough to keep tools in is going to take a lot of work.

Forgive my ignorance - but what's the issue with keeping tools in a shed like this?

 

[Adam W.]

Rust.

I have a small stone shed with a thatched roof, it's good for the mower and mixer, but rubbish for woodworking tools.

The thatched roof keeps it dry and is its saving grace and it doesn't have soil banked up against it, but it's still a palace of condensation.

 

[David66]

Rust.

Ah, of course - now I just feel stupid!

 

[Adam W.]

Don't, we've all been there at some point.

 

[clogs]

if u decide to cover the walls use galv plaster board fixings....
wood is expensive and holds damp where the galv will stop the water getting to the new walls....
it's very easy to make a rough wall straight n level....
as for the floor, I understand the difficulty but I'd be useing a damp proof membrane and the high density foam for insulation and concrete the thing....remember DPM up the walls above the floor as well as an insulation barrier....1" thick will be plenty...it's just to keep the new floor away from the walls.....the insu has many diff thicknesses so easy to get a rough level before the pour.....
PLUS if I were there for a long time I'd put a log fire and back boiler/pump with under floor heating as it's as cold as a Bears "A" hole up there in winter....
if u wanna insu the roof double up on the roof lights as in double glazed...it will swet if single sheets.....dew point....
then just make an internal box around them....wood if u want but I'd use the galv again and insulated plaster board to make it cosy.....
plus nobody I think has mentioned guttering...very importans and make shore the downpipe exit as far away as poss from the building...or....even if u have to dig a stone filled pit/soak away...1m cube will be fine for each down pipe.....u can make it so the road goes over the top if needed...

quite a while ago I did a leaky railway arch for a guy's new workshop...
it was so bad we just built an insulated steel barn type box inside....simples....
good luck....

 

[David66]

if u decide to cover the walls use galv plaster board fixings....
wood is expensive and holds damp where the galv will stop the water getting to the new walls....
it's very easy to make a rough wall straight n level....
as for the floor, I understand the difficulty but I'd be useing a damp proof membrane and the high density foam for insulation and concrete the thing....remember DPM up the walls above the floor as well as an insulation barrier....1" thick will be plenty...it's just to keep the new floor away from the walls.....the insu has many diff thicknesses so easy to get a rough level before the pour.....
PLUS if I were there for a long time I'd put a log fire and back boiler/pump with under floor heating as it's as cold as a Bears "A" hole up there in winter....
if u wanna insu the roof double up on the roof lights as in double glazed...it will swet if single sheets.....dew point....
then just make an internal box around them....wood if u want but I'd use the galv again and insulated plaster board to make it cosy.....
plus nobody I think has mentioned guttering...very importans and make shore the downpipe exit as far away as poss from the building...or....even if u have to dig a stone filled pit/soak away...1m cube will be fine for each down pipe.....u can make it so the road goes over the top if needed...

quite a while ago I did a leaky railway arch for a guy's new workshop...
it was so bad we just built an insulated steel barn type box inside....simples....
good luck....

Thanks clogs. What's "galv plaster board fixings". I googled it but all that came up were screws for fixing into plaster board. I'm guessing its some sort of sheeting material?

I have been thinking about a log burner ... but costs are mounting, and we will only be there for a few years.

 

[Jameshow]

Thanks clogs. What's "galv plaster board fixings". I googled it but all that came up were screws for fixing into plaster board. I'm guessing its some sort of sheeting material?

I have been thinking about a log burner ... but costs are mounting, and we will only be there for a few years.

Think he means galvanised c studs rather than wood. I'd just use treated timber tbh.

Concrete slab seems alot of work compared to a wooden floor?

I'd get a woodburner which you can take with you when you leave. Keep the roof cut out and put back on with flashing when you leave!!

 

[MikeJhn]

You will not stop the damp from the wall with earth banked up against it, so control the water that comes through, a gutter of some kind at the bottom of the wall falling away with the natural slope of the floor, then build a wall in front of the existing wall, for the floor just timber 4 x 2 sat up on legs to the desired height, legs sat on tiles or a piece of DPC, use T&G moisture resistant chipboard for the floor or even a good quality plywood, but coat the underside with moisture barrier paint, ventilation of some kind under the floor to dissipate the moisture would be a bonus, just accept you will not stop the damp, but control what is there.

This was the inside of my workshop/barn:

 

[David66]

You will not stop the damp from the wall with earth banked up against it, so control the water that comes through, a gutter of some kind at the bottom of the wall falling away with the natural slope of the floor, then build a wall in front of the existing wall, for the floor just timber 4 x 2 sat up on legs to the desired height, legs sat on tiles or a piece of DPC, use T&G moisture resistant chipboard for the floor or even a good quality plywood, but coat the underside with moisture barrier paint, ventilation of some kind under the floor to dissipate the moisture would be a bonus, just accept you will not stop the damp, but control what is there.

This was the inside of my workshop/barn:

Thanks for your advice. Do you have issues in your workshop with rusting tools?