Shop Question

[John Martin]

Okay, I'm back life got really busy, and I basically quit blacksmithing and sold all of my stuff. I now have an angle grinder, bench-grinder, and machine vise. I am in the process of acquiring an anvil, welder, and post vise. Will build my forge with my welder. Right now, I have three spots for a shop, one is 12x12, the other is 10x10, and the last one is 16x14 feet. The last one if the one that I am in favor of. However, from the top to the bottom, the land slopes about a foot down. I could either fill it in, or dig it out to make it level. I was wondering what I should do if I want to use the 16Lx14W area for a shop.

[6013]

I favor the dig half, fill half method.

[Dave Hammer]

I agree... Half dig, half fill, then a couple inches of rock dust from a quarry.

[John Martin]

Okay, I'll see what I can do. I can prolly dig half and then push that half over the lower half and make it level then pile either rock dust or pea gravel on top.

[HWooldridge]

The only trouble with digging out the side of a hill is that you open yourself to flooding during a heavy rain. My home is on the side of a hill and even though it was originally engineered for drainage (built in 1972) the house has settled over time and we have had water in the house twice during very heavy rain. The water comes off the hill and cannot get around the structure fast enough.

Not an insurmountable problem but something you should consider.

[John Martin]

What if I dug a little trench starting about like 10 feet from the back that wrapped around to divert the water or just took some extra dirt and built a tiny little levee that wrapped around it to divert the water away from it quickly.

[HWooldridge]

Study on it and decide on something for your situation - either of your suggestions or a combination might work. I don't know what kind of rain you get there or how much grade is above the site. We can get 6-8 inches in an hour when a hurricane comes through - although it may not have rained for the previous 10 months - so we have to plan for deluges.

[Steve Sells]

Pea gravel is not a good option, use crushed rock, like limestone, the pea wont compact, and will shift forever.

[Frosty]

You have 1' of fall to deal with which isn't too severe. Other factors will make a difference of course, like soil type, seasonal percip, etc.

However, provided those other factors aren't too severe ditching and berming should be plenty.

Try to keep the fall on the ditch reasonably gradual and smooth but increasing slightly as it passes your foundation. This will decrease the depth of water as it passes and minimize the chance of log (or leaf) jams. Also gradually widening the ditch is good for the same reasons, it increases the capacity and decreases the chance something will dam it up in a heavy rain. In general wide, shallow and smooth is best. Plant grass to prevent erosion and keep it mowed to prevent jamming.

The berm (dike) doesn't have to be very high, just higher than the ground level around it. Also if it's a gradual slope it's less likely to be overtopped as the capacity increases as the water rises.

The two structures need to be coordinated to be the most effective but they don't need to be big. Basically a wide shallow ditch with the dirt bermmed and compacted on the inside and planted with mown grass.

If grass isn't a likely option you can line the ditch with river rock 2"- over a geotextile is excellent. Just lining with river rock is better than bare dirt, especially if you've just disturbed it by digging and piling.

Frosty

[John Martin]

Thanks Frosty. I will figure what I should do by planning it out again on a piece of paper and with sticks outside. And thanks HW and Frosty and the seasons and precip.

[John Martin]

Well I got an even better spot. 18x16, completely level. Didn't think my dad would let me use it. Ne how, We have like 50 80lb bags of concrete. I was wondering if i could use the mix as flooring. Because it's crushed rock. Or should I just pour conrete. I am hoping I could just use the dust and compact it. I will get pictures in a few days, once I get everything leveled and ready to go. I'm pysched cuz this time im gonna stay with it.

Edited July 9, 2008 by m_brothers

[Frosty]

Brother M:

There's a little trick you can do with cement called, "cement stabilized soils." You prepare your site: excavate the bad soils, replace them with good soil and level it. Then you spread cement at approximately 1 bag per 100-150 sq/ft and rototill it in about 4-6". How much cement and how deep depends on the soil type and gradation, the more fines the less cement you need.

Once you have it thoroughly tilled in level it and run a plate compactor over it. A LITTLE water is good a lot is NOT. If there's any moisture in the soil naturally you don't need to dampen the floor at all, it'll absorb it from the soil.

This doesn't make concrete, it's cement stabilized. It'll be hard and solid but water will drain through it and if necessary you can dig through it with a pick and shovel. UNLESS you do it to clayey soils, then it'll set up like nothing you've ever seen. It still won't be concrete though.

Frosty

[Finnr]

Dang!I learn something new every day! Thanks for the info Frosty!
Finnr

[Pault17]

definitely dang!
thanks Frosty! my father in law has worked with concrete (he liked to build schools and banks) and thinks that is a cool idea too.

[John Martin]

Awesome thanks frosty. That's something new that I'll have to remember for a long time. I forgot to say that I don't have a plate compacter. Could I just role a huge log acrossed it or use a 6x6 post with my dad and go along and use it to compact it??? It'll take a while but still. OH and the shop won't be built for like 5-10 days after this. Should I hold off on it, or just keep a tarp over it, cuz the 10 day forecast looks like rain possibly one day.

Edited July 9, 2008 by m_brothers

[Frosty]

Sure you can hand compact it, we did so in the barn, it's just a lot more work. Rolling a log won't do it, you want to use a tamper say a 6' 4" x 4" post on end. A "regular" tamper has a 6" sq steel plate on a long straight handle and weighs probably 10-12 lbs. You'll want to use a little more water on it too but if you start seeing free moisture at the surface when you're tamping you've applied a little too much.

If you're using a plate compactor this much water will turn it to a muddy mess. It'll be cement mud all at the surface and the aggregate (sand and gravel) will be separating. A plate compactor works more by vibration than it does by weight; vibration compaction requires a fairly dry soil.

Hand tamping works by impact compression so more lubricant (water) between the particles is necessary so they can move. Too much water will start filling the voids (spaces between particles) you want filled by soil, you know you've hit this point because the water will start pumping to the surface. (free moisture) It'll be taking the fines, silt, clay and cement necessary for the soil to compact properly with it which is a bad thing.

Once it's compacted a little rain won't hurt, a lot won't be good though.

What kind of soil are you building on? Gravel, clay, ? It makes a difference.

Frosty

Edited July 9, 2008 by Frosty

[Thomas Dean]

You beat me to it Frosty! Although I have never done a floor like this I have seen a few of them. And it true about the clay soil! Got a neighbor that can't drill holes to mount anything to the floor because they used too much water! Cleaning may be a problem if you want to sweep it all the time as it will not finish out as smooth as a concrete slab will. Also, 'Lil Bro, I would rent a compactor. It should only take a couple of hours at the most and you can rent for 1/2 day. The compactor will do a much better job and the cost is minimal. I can rent one for under $30.00per 1/2 day. YMMV Good Luck

[John Martin]

Good Rich Soil to a kind of clay/soil about 10 in down....Good news, I will be getting a compactor tomorrow. Next question, can i till the cement in and then wait until tomorrow to compact it?

Edited July 9, 2008 by m_brothers

[Frosty]

Yeah, well. I worked for the State of AK geology section of materials HQ for about 20 years. Part was in the soils lab, the rest as a driller. Having spent the time in the lab really came in handy even on the drill crew.

Clay soils are problematical if you can't isolate them from excess moisture. One of the defining characteristics of clay is it's hydrophilic, meaning it wants moisture and will continue to absorb it till it's well past it's liquid limit. Some clays are more so than others, bentonite for instance is EXTREMELY hydrophilic.(that's the wrong term but I don't recall the right one) Bentonite will continue to absorb water indefinitely AND evenly distribute it throughout the volume of clay. Basically if you were to drop a tbsp in the pacific ocean, eventually it'd be evenly distributed through all the connected oceans. Weird stuff in general and bentonite is bizarre in the extreme.

Anyway, compacting clays require much less moisture as the particle sizes are so small, plate structures, 1 micron x 2 or 3 microns x 5 microns. This makes them compact nearly to stone densities but makes it hard to get rid of moisture as it can only migrate horizontally. The platy structure also makes it absorb water voraciously through VERY strong capillary action, causes even distribution and when semi-molten vitrifies into a nearly indestructible mass. (ceramics) Of course all clays don't vitrify but most do. If they don't it's usually because of organic contaminants.

If cement stabilizing clays you only want 1/2-1% cement by weight and depending on the clay, 5-9% water max.

A better method for stabilizing clays is with sodium sulphate or calcium chloride. The sodium sulphate forms crystals in the soil that stick it together quite well. Calcium chloride is hydrophilic and draws moisture from the air keeping the clay at optimum moisture.

Both of these methods require the correct amount of stabilizing chemicals and long term (say winter) variations in humidity can effect the compaction.

[John Martin]

I won't reach the clay. But my question is, can I till the cement in and then compact tomorrow. Sorry if you didn't understand my post.

[Frosty]

I won't reach the clay. But my question is, can I till the cement in and then compact tomorrow. Sorry if you didn't understand my post.

Sorry, my fault, I got off on a tangent sparked by Thomas's post.

If rich means a lot of organics in the soil you should try to replace it with mineral soil. Organics are nothing but trouble for any kind of foundation.

If you loosen the soil with the tiller before spreading the cement it'll wok better, you want it uniformly mixed.

Moisture content is important, just enough to compact well but not so much it pumps. If it'll clump with a good hard squeeze it's good. If it's sticky it's too damp, try tilling deeper to mix in drier soil from farther down.

Once it's well broken up, level the area, sprinkle the cement in a reasonably uniform layer and till it till it's well mixed, then compact till the compacter is rattling on the hard hard ground. Lastly, let it set at least a few days if you can.

Sorry about confusing you with my last post.

Frosty

[John Martin]

Well I've got the floor done, and I was wondering if it costs around $300 to build the shop, and I could just work outside, should I just forget building a shop, and just work outside???

Only downside would be, that I would only be able to forge when the weather permits.

Edited July 15, 2008 by m_brothers

[Bentiron1946]

Now that you have the floor down you can build rammed earth walls. Same idea as the floor only use the cement/soil mix in a wood form and ram it down hard, then move the form up and do it again. Dirt cheap as they say:D

[John Martin]

I think I'm going to just work outside, and then either cover it under a tarp or move into our shed when im done.

[Frosty]

So why the change of plans Brother M?

It's not like you have to stop what you're doing and build it all at once. I've been working on mine for better than four years now and still haven't gotten the vehicle door on, insulation nor wiring in it.

Extension cords in a dark cold shop still beats heck out of working outside.

Frosty