Improving the floor of smithy

[urnesBeast]

I have recently been playing with the idea of several strategically placed floor jacks. I can crawl under the smithy and install those without much issue. I figure a couple under the anvil will do wonders.

[Frosty]

Floor jacks might do it and they're economical enough that if they don't you aren't out much.

Putting sonotubes (cardboard tube concrete forms) in strategic locations will work as well, especially under the anvil. If you use them to shore up joists put a piece of treated ply between the concrete and the joist.

Frosty

[IronPuppet]

This is what you should do in my opinion.

Put a piece of heavy plastic down to cover the whole floor. Tie wire a grid of re-bar over the plastic in a 4' grid and put it on 1 1/2" spacers to hold it off the plastic. Pour 3 to 4 inches of concrete throughout the building and level off and flatten/smooth the floor as you would any cement surface. The floor will be stable and solid not to mention fire proof. Put your anvil anywhere. No bounce or movement at all.

I lived in an apartment once and this is how the apartments were sound proofed from the one below. At one time a friend of mine was living in an old house and the floorboards were starting to dry rot and fall apart. Subsequent plywood patches made for a very uneven floor. He was at a loss as to how to fix it. All estimated were astronomical. One day I came in there with a big sheet of poly and ten bags of cement. After the cement set the floor was a solid and level. The next week he laid stick-down tiles over the cement. That was ten years ago and he hasn't had a problem with the floor since and we never used re-bar, but it's just a domestic dwelling.

If your worried about weight, you can get leveling cement for floors that has pearlite in it and is lighter than regular cement.

A thin coat of cement won't cut it. It will crack and be a mistake.

Make a solid cement floor. You will never regret it.

Christopher

[urnesBeast]

Christopher,

I was thinking of doing this for the fireproofing aspects, it sounds like it will also help with the anvil bounce? I am guessing this provides such a large mass that it is similar to being truly grounded to the earth?

I see there are premade wire meshes, is that acceptable, or is real rebar what is needed? I like the idea of the plastic being put down. I was going to do it incase I ever wanted to take the floor out, but this sounds like it would never come out anyways. What is the purpose of the plastic then?

-Thanks,
Doug

[saintjohnbarleycorn]

I think regular concrete is around a ton per yard, the light crete I got was 1200 or so a yard, maybe 1500 so still a lot of weight. just keep that in mind when planning.

[urnesBeast]

Here are the plans:

This is the design I used for the smithy:

Great Sheds - With Plans - Popular Mechanics

Here are the plans:

http://media.popularmechanics.com/do...505shed001.pdf

So, I am no engineer (oh wait, I am) but I did this building "Overbuild" it style. The runners are 2x10, and the flooring is heavier duty, the beams are slightly bigger too. I suspect the weight will not be a big deal.

-Doug

[sawyer04]

I just got a lean to on skids with 1/2 inch gravel floor. Anvil mounted on locust stump buried a couple feet in ground. I build it on skids because the tax man here likes any kind of permanent structure too much.

[rfb343]

Mark,

If I hear you right, you are saying I could take foundation blocks to build up a box, fill it with soil and compact it. Saving on concrete cost and making it bigger. I think that I could wrap the supports in plastic or air gap to make the support box bigger.

Thanks!
Doug

Doug yes, you heard me right, another thought I had later was to use big timbers to build your box with the compacted dirt inside. If you have access to RR ties they'd probably be cheaper than block at least in my neck of the woods. and easier to work with. I figured you could frame out the hole you cut in the floor and throw some posts, jacks, piles of rocks, etc under the perimiter of the floor hole and you'd be good. One thing to remember, you're trying to bend hot metal between to hard objects, dont over complicate things.

[IronPuppet]

Christopher,

I was thinking of doing this for the fireproofing aspects, it sounds like it will also help with the anvil bounce? I am guessing this provides such a large mass that it is similar to being truly grounded to the earth?

I see there are premade wire meshes, is that acceptable, or is real rebar what is needed? I like the idea of the plastic being put down. I was going to do it incase I ever wanted to take the floor out, but this sounds like it would never come out anyways. What is the purpose of the plastic then?

-Thanks,
Doug

Doug, that pre-made wire mesh is made for light duty, as on a sidewalk or patio floor. You should use re-bar in your shop because of the heavy vibrations and possible weight bearing requirements involved in shop operations. A ring of re-bar around the perimeter about 8" to a foot from the wall and then a grid at 4' on center. If it was my shop, I would opt for more re-bar and make it 3' or even 2' on center, but those in the know would probably say this was overkill.

The plastic acts as a moisture barrier and helps keep the wood dry and rot free. also seals up any unnoticed holes where cement could leak out during the pour.

[urnesBeast]

This is what you should do in my opinion.
...

Make a solid cement floor. You will never regret it.

Christopher

Christopher,

My father is a general contractor, when I told him of this idea he was very concerned that the concrete would get broken up pretty well after a while. "You hammer it to break it up when you are done with it, son." I think this would be a fine plan, but it is tough to argue with a dad...

Anyone know how to answer his objection? I am not afraid to overbuild with rebar.

This is looking more costly than I expected, I am thinking of just doing half the area, the hot area. That make sense because I would have to pour around the door anyways. It looks like going and buying quickcrete is the right way to purchase cheaply.

-Doug

[Sam Falzone]

If your shop is the same footprint as the one in the plan you posted 10'x12' (not including the porch area) and you pour a 4" pad as suggested earlier on, you would be looking at using 1.48 cubic yards of concrete - that's around 89 60# bags of premix (checkout Concrete Slab Calculator - The Concrete Network)
You would also be looking at around 1.5 tons of weight (not including the rebar) just for the floor. Then you'll be piling on what ever tonnage of tools machines and "stuff" over the years. You could easliy end up with some severe structural failure over time.

Doug, I think I understand what your dad was saying and I think he has a point. If the floor ever fails or you want to get it out, you're never going to be able to bust it up with all that rebar inside without busting the shop down around you (especially if you go with a grid smaller than 4'x4'). I think he's just sayng "think long-term". It's hard to come up with an arguement against his logic though.

Your idea of doing half the floor has merit and historical presidence. I did some work in a historical smithy many years ago and I remember that shop had half of its floor as brick and compacted sand (the "hot" half) and the other half was a plank floor (where they worked on the horses). So it's possible.

You could frame in the hot half of your shop floor with a 2x4 sill and fill in the area with paving bricks, giving you a fireproof floor, that is solid enough to keep your anvil stand mobile if you need to move it, but is also removable if you want to change it later. The gaps between the bricks can be filled with fine sand to prevent embers from getting down to the wood floor beneath. The plywood floor should be flat and level enough that you won't need to lay down a sand bed.
Just an idea.

Sam