Robin

Like you I know nothing about building materials or techniques, but having said that I would have thought that a plastic membrane under a concrete plinth would cause the plinth to be liable to move. I would venture to suggest that machine mounts would be a better option, provided that the flagstones were solid these would enable you to level the machine on the uneven floor without damaging the flagstones. I do not envy you getting the machine into the cellar, sounds like a job for a specialist to me.

Wow, that's a big heavy lathe. Looks like it comes with a stand which no doubt sets the machine at comfortable height if the stand is placed on the floor. I think the idea of pouring concrete over the floor (with a plastic membrane to allow removal of the concrete in future) is good, but the weight of the lathe may well crack it unless it is pretty substantial in itself. Making it too thick though might raise it up too high.

I was inspired by some web articles about lathes made from concrete during World War II. I wonder if there would be a benefit in making some sort of reinforced concrete plinth, similar to how concrete floors for buildings are reinforced with steel 'rebar'. Something along the lines of making a box mould, laying in the rebar (they usually bend the ends to stop the rebar pulling through the concrete), placing in position over the plastic membrane and pouring in the concrete. Perhaps a depth of 5 inches or so? With some rebar in the lower half and also some in the top half.

The benefit would be to spread the load of the lathe evenly to the floor over the entire surface area of the plinth. Machine mounts will put the loading at specific points which may do untoward things to your flagstones, and depending on how they were installed, might they move under point pressure?

Might be worth looking in machine mart for some chain hoists or similar to help you move it. Some of the engine hoists might be useful too, but not sure of their maximum weight capacity.

My workshop floor is simply the common builders green (waterproof) chipboard tongue and groove underflooring boards. Laid direct on concrete with re-enforcing mesh and left naked with no finish or protection applied its still in good order after nearly 10 years. Well up to supporting quite heavy machinery viz Smart & Brown 1024 lathe, Pratt & Whitney model B lathe, Bridgeport mill on their standard feet without damage.

Flagstones tend to be cold and damp so in you position I'd put a good quality membrane down and cover with self levelling compound. The load wills pread nicely. Probably best to set battens at intervals and do the job in several steps to help get a true surface. Just glue the flooring board together and down. Make sure you get the quality green stuff. Round here the allegedly just as good natural colour stuff is rubbish. Very dusty and soft surfaced.

I'd not worry that much over what's under the flagstones although you may need to check drainage and damp venting. Even an apparently dry cellar may vent a little water through its surface and joints to keep things in balance beneath If they have been there many years and are properly settled the falgstones ar'ent going anywhere. Heck I know of a Bridgeport, Harrison 15" lathe and Victoria U2 mill which are basically sitting on plain dirt with about 3 sheets of 3/4 ply underneath. Helped move them in and all seemed to work OK but …. Turns out that particular workshop was built by simply sinking a normal shed style wood flooring under frame into the ground with an outer ring to build the walls on. Then more or less infilling with dirt before nailing plywood on top and building a timber shed on top. Current occupant put another layer of ply down 'cos it was all a bit springy and added a third layer where the machines were going just in case. Yikes!!

Clive

Edited By Clive Foster on 01/09/2014 22:35:24

Robin, sounds like it's a Victorian house? Well most of these cellars are damp, and more than you might think. Personally I would tank the cellar, there are quite a few companies do this at reasonable cost but it depends on where you live and how long you intend to be there to justify the cost, my guess it's a long term house?

The stone flags are quite valuable so you could lift these and sel them to offset some of the cost. The floor would be best concreted with a membrane and if you did not want to go to the cost of tanking the place I would then line the walls with studding with a membrane behind it and board the inside with material of your choice, plasterboard, plywood, etc.

hope this helps and good luck. John

ps see your messages

Edited By JohnF on 02/09/2014 08:22:03

As Graham says thin self leveling compound on a membrane is considered bad practice due to the risk of cracking. However my limited, 5 cases, experience of self levelling compound on a membrane suggests that it may not be a major problem provided whatever is underneath is solid with no tendency to move. The one I pulled up after about 6 years varied from 1/8" to 1/2" thick and was fine despite having machines stood directly on it. Cracked apart wonderfully when I heaved on the membrane to shift things tho' which made for an easy clearance. Admittedly it was a short term job which worked out well.

If you use the sort of flooring board that I did cracks in the levelling compound won't really matter as its primarily there to transfer loads directly down through the boards onto the substrate. Large voids are the worry not cracks. That board makes excellent short ramps for machine moving too if you put full length timber wedges about every foot. I have a 7" step into my workshop and a 2 ft 6 long by 4 ft wide ramp made in that manner took all the machines effortlessly. Great as shelves and bench tops too.

Clive

Hi Robin, I am just completing a very similar job, and this is what I did. It is not in a cellar, it is a house in East Yorks that is built on solid chalk, and also built into a chalk bank up to the depth of the first floor. The down stairs floor was victorian clay tiles on top of fine chalk gravel which was underlayed by solid layered chalk. Needless to say it was very damp. The tile floor was taken up and dug down 6" it was then levelled, a damp membrane was put down, followed by 2" jablite insulation, Which was also placed round the wall edges to a height of 6" as perimeter insulation, another membrane, and 4" of concrete. Both membranes are folded in the corners, not cut, and made big enough to go about 2 feet up the walls all round. I then screwed 1" x 2" tanalised lath (tile lath) to the walls, placing a layer of plastic (for brickwork) DPC behind the lath. 2" jablite was fitted between the laths and fitted tight up to the perimeter insulation.The entire wall is then covered with DPM which goes behind the overlap from the underfloor membrane so that any moisture drains down into the subfloor and percolates away The walls can then be finished with plasterboard or whatever you like. It is quite a lot of work, but it has turned a damp, smelly, unusable building into a warm dry area that can now be used for any purpose, and the cost of materials, even using readymix concrete was under £1000.. I have some pictures if you are interested, and if I can work out how to post them!

Phil.

I had the same problem as you. I purchased a Chester 12×36 Geared Head lathe and had to get it into my cellar workshop. The lathe weighs about 650Kg and I was warned NOT to remove the headstock to ease getting it down the cellar steps. I didn't remove the saddle 'cos it helped to balance the lathe during the move. The bed was attached to a hefty lump of wood that could be used as a skid. All moving was done on short lengths of scaffold pole rollers.

I rigged up a sort-of ramp on the cellar steps – it had saw-tooth shaped supports that rested on some of the stone steps. I also made a reinforced surround to the cellar door, which held a length of scaffold pole to which I fastened a small block and tackle. The lathe was manoeuvred to the top of the cellar steps, and the block and tackle used to control the descent. The rest was just plain sailing by the use of rollers and an engine crane.

The lathe sits on machine supports on a 4" thick concrete floor laid over a membrane on earth. It was installed in 2003 and its fine and stable.

I made some duck boards to stand on – warmer than the floor and the swarf drops through the slats.

Edited By Gary Wooding on 02/09/2014 16:02:16

Hi again Robin, It sounds like a beautiful old building, and having a level(even if cobbled) yard door entrance to the cellar is excellent. Remember that the secret to get rid of a lot of dampness is ventilation, if there is moisture in the air it will condense on any surface that is colder than the air, the trick is to get the air moving and keep it moving through and out of the building all the time. Low speed fans use very little energy and can move the damp air out of the building. Also something I forgot to put in my first post……Check all your rainwater downspouts and gulleys, and check that the undergound drains that take the surface water away are clear and not leaking anywhere. Some years ago a friend bought an old vicarage with a very damp cellar, and we found that most of the damp was actually coming from blocked surface water drains which were flooding over and letting the water go down between the ground and the house wall, We lifted some of the gulleys out of the ground as they had sunk, and found that the reason for this was that rainwater was going down between the gulley and the house wall and had washed all the fill out from under the gulley. When we put these right, the dampness dissapeared although it took about 6 months, and we did install some fans as well.Where in the country are you?

Phil,

East Yorkshire

As you have a solid floor you have absolutely no need for layers of concrete or self leveling stuff. The lathe stand will have 4 or 6 mounting holes in the corners of the cabinet sections. Just put jacking bolts through these. If holes not present and you don't want to make them you can use shims of metal and hard wood. Either way the flatnes of the floor is utterly irrelevant.

You already have a dehumidifier. Just keep it running and block off all the draughts. It will provide background heating aswell as free distilled water. Only if you find it is still filling its tank every other day will you need to take action. Since some walls are effectively above ground you can insulate them to advantage without too much risk of damp. The other walls might be more tricky to insulate without causing a problem of sealing damp in. If the floor proves to be seriously damp raise the lathe and machines on breeze blocks then create a wood suspended and insulated floor that has a 1in cavity underneath its DPC to allow forced ventillation

I would still check the floor for damp Robin. When I did my place the walls seemed far wetter than the floor, but when I took up the tiles, put in a dpm and concrete, the walls dried out. It was damp from the floor condensing on the walls, which were colder. Get some air moving through before you commit to any work, it might dry out by itself, unless you have leaky rainwater drains, as we discussed before.

Phil

There are now huge taxes on new build to make it unecenomic except for large building corporations.

I agree.

There are thousands of properties with damp cellars that never were so before previous owners and botch-it-men sealed up air bricks and general ventilation.

Air movement is one of the best things for curing many damp problems. Even a small extract fan tricking over can work wonders in many situations.

Nick