Talk to be about workshop floors

[sako243]

The new place came with a pair of buildings in the garden which are on their way into being converted into usable workshops and laboratories.

The stables (pictured below) will be have a "garage" at one end (where the Defender is nosing through the door way) and "clean" machine shop downstairs. Once the floor is reinstated then the electronics and computer labs will be upstairs. "Dirty" workshop (welding / grinding etc) will be in the blacksmiths forge area which is attached through the normal sized door in the first photo - but that's not a priority at the moment. The plan is to keep the entire thing open plan but potentially with a curtain / sliding partitions to separate off the garage end if required (at a later date).

Historically it was a set of stables for the doctor's horse and cart. Consequently the floor is on a slight slope (highest point in front of Defender). There are no foundations to the barn as is typical of buildings of this vintage but everything is structurally sound and the roof has been recently (in the grand schemes of the property) re-done.

The hole in the floor is where the set of stairs up to the first floor was previously - these are being relocated towards the corner by the wheelbarrow to keep the open plan nature.



Partial history lesson over - the floor is being lifted out and being kept for repurposing elsewhere on the property since it has some nice slate slabs and bricks with the little tiles embedded in them.

So given that this will house machinery - currently the heaviest single item is a Bridgeport mill but knowing me they're only likely to get heavier - I'm after some recommendations / suggestions for the flooring.

I'm thinking a minimum of a 6" slab (which conveniently takes it to a full lorry load of cement) but what should the structure below / surrounding it be. I'm not going to do this twice so will be getting it right the first time.

Current plan of attack is:

1. Lift out existing flooring
2. Dig out floor (mostly soil, there is likely to be shale 1 foot down if the rest of the property is anything to go by).
3. I want the top of the floor to be level with roughly where the rear wheels of the Defender are - this means it is an inch or two above the grass outside and maximises door height.

So there should be a damp proof membrane - but given the lack of foundation should this go up the wall a little bit (this will be re-pointed externally and then rendered internally). The building is on a gentle (for Wales) slope (highest in front of Defender) and the neighbours farm yard is behind the wall.

Rebar?

Any hardcore / rubble-base?

Planning on doing most of the work myself to keep costs down - after buying the place there aren't many funds available for labour .

 

[Barking Mat]

Hardcore base, gravel, sand, DPM, insulation, rebar mesh, concrete.

Generally.

 

[SteScouse]

Before i get booted,i just want to say i i couldn't walk past it, i mean really, i could'nt

Computer labs, blacksmith forge area, Bridgeport mill and huge slabs of concrete

Tell ya what sako, if the cash is running short now, PM me, I'll lend a hand for a day

Sure others would love to see the place too

 

[addjunkie]

Careful once you get the old floor out, digging too much out you can end up below the non foundations and cause major structural issues, and will need underpinning.

Type 1 hardcore, officially should be 6 inches, blinded with sand, membrane, Id take it above the ground outside, or dig it back and have a small gravel trench aound the outside to allow the bottom of the wall to breathe.

If its once in a lifetime Rebar mesh 1 or two layers couple of inches apart. The concrete, 6 inches, If you want a really good level floor, get the stuff with 10mm gravel and runny, and have it pumped in so it self levels. Has a speacial name but forget what it is.

Or you could skip the steel and use the stuff with fibers in it. Make sure you get a strong concrete mix! R 35 I think it is.

 

[jerrytug]

What a fantastic gaff, I dont know anything about floors..but how old are the roof timbers. what are they like have you been up there? You can often find very interesting things, and clues to the previous lives of the beams.

 

[sako243]

Computer labs, blacksmith forge area, Bridgeport mill and huge slabs of concrete

Um, might have forgotten some of the tools , I did say the heaviest item I had, although the three Elliott drills and table I acquired off @8ob are a close contender. It is ultimately intended for the business to move from the farm to here in the future so doing it once and doing it right. The forge is non functional at the moment but probably aim to keep it and maybe reinstate it to keep some of the history since I've demolished the stables (they were riddled with wood worm).

What a fantastic gaff, I dont know anything about floors..but how old are the roof timbers. what are they like have you been up there? You can often find very interesting things, and clues to the previous lives of the beams.

The roof is in good nick - the previous owners had it off for repairs a number of years ago. I did venture up reasonably close but the floor was rotten so was very careful where I went (you can see the previous floor level). Did find an old skin / comic book in one of the stud walls but didn't see a date on it - think I might have put it to one side to see if I could date it, don't think it ended up in the bonfire.

The barn has always been a stables - from what we've heard the place was built for a doctor in the late 1800s (although I'm fairly sure I've seen a picture of the ladies of the house dated 1840). The stables housed his cart where the Land Rover is parked and then there were what looks like three stables originally (due to the alcoves in the wall - presumably for hay) but one got bricked up and three stables became two. The previous owners just used it as junk storage, they hadn't been up on the first floor for decades - hence why I found a 15x5x9ft (width x depth x height) jackdaw nest up there.

There's a lorry load of scaffolding being delivered next week so once that's in (bought outright because it's cheaper long term - particularly with the height of the house) so once that's arrived I can finish retrieving the final bits of wood off the rafters.

@addjunkie that was very helpful thank you. The back side of the wall is a little trickier - it's part of the neighbours farmyard but she wouldn't have much objection to doing some work there. I can't remember what the floor was like right up against the wall, it might have been part of a large concrete slab. I'll pop my head over the wall when I remember. Problem with this place is as you wander off to do one thing you get distracted with doing something else. E.g. found a hidden cellar this week under the sitting room (suspected there was one there but my sister was down and "borrowed" a bore scope from work and we got it down via some of the holes for the central heating.

I'll lend a hand for a day

Did think about it - funnily enough there's a load of scaffolding fixings that might need picking up in Liverpool at some point. As it's all nice and open I suspect once the ground work has been done (shouldn't take too long) then actually pouring the concrete shouldn't take too long since it's basically one lorry load and the firm my folks have used before had all the necessary pipes to pump it in. Dad did a floor in his milling workshop a while ago and that was more awkward to access.

 

[SteScouse]

Wow mate you got a lot of good gear, guessing the skills to use it too

Can you point me to threads where you've posted stuff you've made.

i must of missed them somehow

 

[Arc Tourist]

…………………………….. If you want a really good level floor, get the stuff with 10mm gravel and runny, and have it pumped in so it self levels. Has a speacial name but forget what it is.

I believe its called Agilla Mix. My neighbour had it pumped in for the ground floor of their house.

 

[mike os]

If the heaviest is a BP mill or the landy then 150mm is thick enough with 2 layers of a142 or similar with 50mm off the surfaces ,

Excavate for at least 150mm well compacted mot type1 hardcore, 50mm sand blinding.

Dpm on blinding turned up the walls, if you want it insulation ,( minimum 75mm, less is just not worth it, if you do you want 25mm all around the perimeter too)

Looking at if you will need to do it in a couple of bays to mimimise cracking... on 150 slab should be about 6m or so, it also makes it a bit easier to work... I wouldn't worry about leaving a joint though, just drill in some starter bars and cast against the other slab.

For a workshop you want a normal concrete mix, tamp and self level after or power float if you can.... timing and practice needed to get a good finish.

Liquid poured is likely to be very expensive for what you want

 

[mike os]

As far as founds ... if they are really shallow do it in 3 or 4 bays and then self level...when complete

 

[Robbair]

Careful once you get the old floor out, digging too much out you can end up below the non foundations and cause major structural issues, and will need underpinning.

I have done exactly that in an old building, 19th Century foundations (in my case much older) aren't governed by building control! You don't necessarily need to underpin but you do need to take care how you go about it. I would recommend a couple of test holes, guarrantee you will find the downhill different to the uphill. Water ingress is your enemy while you dig down inside, with winter on its way it might be better to get help and get the job progressed rapidly than to chip away at it on your own and risk damage to the walls from a flood.

 

[Arc Tourist]

Hardcore base, gravel, sand, DPM, insulation, rebar mesh, concrete.

Generally.

Agree, except for the underfloor insulation, as the floor is for heavy machinery installation and you have a high open ceiling which would seem to make it rather pointless. Kingspan insulation as its called, may be fine for residential use, but its foam and foam will obviously deteriorate and compress in time leaving cracks and possibly an uneven floor. Also, this may affect the accuracy of machinery, with lathes being an example, which are installed and precision leveled for functional accuracy..

I was "required" to install 75mm insulation under the new floor in the house we are rebuilding, but, there was nothing mentioned saying that I couldn't place a breezeblock here and there (where I felt appropriate) to support the slab directly on the compacted grade. This may an option to consider if one needs planning approval ?

 

[MCKDAVID]

...Or you could skip the steel and use the stuff with fibers in it. Make sure you get a strong concrete mix! R 35 I think it is.

sorry mate, totally disagree, what a pile of scrap that stuff is... Unfortunately I was talked out of using steel and fibres into just using fibres, on an 100mm pour for an original slab of 10 x 6m.. Big mistake, within 6 months, major cracks galore. Fibres certainly not a replacement for rebar, might work well in parallel with rebar, but not as a replacement. It would be ok for avoiding surface cracks ok, but we have full depth cracking, even with cut expansion joints. I've often thought of having it dug out and redone, but too much hassle now, so we just live with it..

Every pour I've done since has steel in in even if it's only a wee pour (chicken shed for example has rebar too and it's only 50mm thick...). wouldn't thank you for that fibre crap.

 

[sako243]

If the heaviest is a BP mill or the landy

It is currently. Buuuutttt I was previously limited by what I could fit through a narrow alleyway to a 12x10ft shed... Now I'm limited to what'll fit through the doors, one of which is being made larger so a tractor can fit through (well that's the plan).

With regards to ceiling height: remember there's a first floor going back in so the ground floor will be about 10ft tall (if I remember correctly). Planning on insulating walls, floors and roof. Because I'm about 20 miles from the Atlantic south, west and north it's worthwhile if nothing else to keep the machines dry rather than having to run dehumidifiers as the farm does.

 

[sako243]

Regarding wall insulation the plan was to render the internals to make them watertight (exterior is being repointed with a lime mix) to be breathable. Once the interior done then probably put in a stud wall with insulation behind it.

Will have heating by the way of a log burner with back boiler courtesy of @puffernutter. Don't have a shortage of wood between pruning at my place and the woods at my parents. There's already in excess of 50 cubic metres of seasoned firewood in a barn there and that's mainly because we've run out of space in that small barn, there's consistently half of that a year in fallen branches etc.

 

[mike os]

If you might go heavier go to 200 mm on the slab, unless you are going really big in which case still go 20mm and cut out pads for machines

 

[addjunkie]

Regarding wall insulation the plan was to render the internals to make them watertight (exterior is being repointed with a lime mix) to be breathable. Once the interior done then probably put in a stud wall with insulation behind it.

Will have heating by the way of a log burner with back boiler courtesy of @puffernutter. Don't have a shortage of wood between pruning at my place and the woods at my parents. There's already in excess of 50 cubic metres of seasoned firewood in a barn there and that's mainly because we've run out of space in that small barn, there's consistently half of that a year in fallen branches etc.

If you insulating the walls even if water proof renderd youll still need a membrane in the stud wall too. Or you could just dot and dab insulated board straight onto the water proof render!

If your goung clean / dirty area, freezer strip curtain between the two works well.

 

[sako243]

If your goung clean / dirty area, freezer strip curtain between the two works well.

No need

There's an adjoining door to another barn for the dirty area

See right hand corner of the first picture. There's another barn through there that's about 2/3 the size of this one (with old forge included)

 

[knighty]

I thought shale was fine to concrete right on top of? - I always have and had no problems

you want rebar mesh in there, fibers are optional... but no reason not to tbh

the entrance way needs to be the toughest bit, that's were you'll bring stuff in/out and where the weight shifts from the ground outside to the concrete inside.... (everywhere inside the floor is supported by the floor around it)

 

[sako243]

I thought shale was fine to concrete right on top of? - I always have and had no problems

I think you're right knighty, all the farm yards and barns around here usually just pour the concrete down. Ok they do crack eventually but then again my parents yard which sees a lot of delivery vans and during the summer regular tractor use (during the neighbour cutting silage that'll have 40+ tonnes going over it) and its had its first repair patch in 25 years last month.
Ok not workshop smoothness but no rebar, hardcore or sand.

I think I need to do some test holes to see where the shale is. Also the land here has a lot of old slate land drains so everything stays nice and dry, and I'm almost the highest point but with lots of slopes and drains to keep it dry from initial investigations.