concrete pad for drying

[Dan_Shade]

I'm putting a 10x10 concrete pad out in my yard for a place to stack fresh sawn wood.  I'm probably going to make a roof over it eventually, but that will be down the road a bit.

I'm assuming the pad should be as close to flat and level as I can get it, and not to worry about water runoff from rain?  or should I slope it a little bit?  I'm planning on digging out 6 inches, puting 2 inches of gravel in, and then 4" of concrete on top of that.  I may change my mind and try to leave the concrete above the ground some.

one last thing, this pad will be over the leechfield of my septic system, I guess i'll put some plastic down to keep the water from coming up, but is this a plain bad idea in general? problem is I really don't have another spot to put it.

[Ernie]

I'm putting a 10x10 concrete pad out in my yard for a place to stack fresh sawn wood. I'm probably going to make a roof over it eventually, but that will be down the road a bit.

Pardon my ignorance but wouldn't it be more effective to build the roof over the pad rather than "Down the road a bit"

[Dan_Shade]

i never do anything the easy way. 

my short term solution is to make a frame, and hang a tarp over it.  I have to look into the building codes and such...

[Minnesota_boy]

If you put it over the leaching field, you'll have opportunity to make a new leaching field within a few (maybe very few) years.  The leaching field gets rid of the waste water by soaking away and by evaporation.  Not much evaporation through 4" of concrete.

Maybe you would be better off putting the pad on the neighbor's land? 

[hardwood]

I'm certainly no expert on septic systems, but from everything I have been told about how to maintain mine, this does sound like a bad idea and may even be against code. Compaction is one of the big enemies of a septic field. You are talking about digging up part of the dirt, and replacing it with a couple tons of concrete. Then you will be dealing with more compaction as you move the wood back and forth. Not sure about your codes, but here you cannot put anything on top of septic field, and especially not any type of permanent structure.

[Furby]

You will REALLY screw your septic system!

On the other hand, there is a TON of heat coming off that thing in the winter, if you have a large family that is.

Really, find another spot!

[Dan_Shade]

ok, I didn't know if the water would evaporate up, or soak down...

i guess i'll find another spot for it.  too bad the idiot here before me put a 16x16 shed on it too, at least the shed is on blocks, but probably not good for the shed's floor.

i'll have to clear a spot out in the woods, I suppose

[beenthere]

Yup, right where you cut some firewood trees 

(maybe put the drain field over on the neighbors  )

Some thrown-away pallets make good firewood base for stacking firewood, for me.

[Dan_Shade]

i'm using this to dry boards, not firewood

[beenthere]

Dan
Sorry, that went right over my head. I was thinking firewood all along. Need to read the fine print here. Now your pad makes a whole lot more sense than at first.........

[Dan_Shade]

I'm not stupid, I just pretend to be at work!!!

well, this is the second time I've started digging in my yard and the septic system got in the way, first time was for a barbeque pit, I found my distribution box, and now this (so maybe I am a bit on the slow side)

oh well, i'll scope a good spot out in the woods, might be better anyway, not as much sunlight

[Tom]

Dan,
You sound like you do what I'm accused of doing.  Here i am with 47 acres and I have everything shoved so tight together that I have trouble turning my truck around.

It's the same kind of logic as stacking all of your stuff inside the door of a garage so that you can't get to the empty space inside. 

[Dan_Shade]

well, the layout of my house and lot is far from ideal in my opinion.

real estate around here has gotten crazy, you can't even buy plain land now, unless you're really loaded, so you have to sorta take what you can get.

what I could get was a house on an acre, probably half of it is wooded, mostly pine trees, the house is crammed into the front quarter of the lot, presumably so that whoever put it here in the first place could later subdivide.  the driveway is on the wrong side of the house as well.

In the meantime, i'm trying to figure out what I want to do that won't cause me problems down the road.  First off, I need to get my lot surveyed where they actually put stakes in the ground ($300 just gets them to give you the plat from the last time around here...), then I need to fence off my woods from my neighbor, who seems to think they're a good place for his kids to play.  maybe then I can put in a second road entrance, and put a garage in the woods, problem is an acre fills up real quick, especially if you want to keep some privacy, if you can even consider having an acre "private"....

blah, woe is me!!!!

I guess I could have bigger problems.

[Furby]

I hear ya!
I have an acre and a 1/4 and the driveway is on the wrong side too. Or is the house turned wrong, ahhh.
Power comes in over the driveway making it hard to bring in something big.
(Now who would wanna do that )
Sewer line is 16" under the driveway, so I can't cut the grade down.
Not enough room for all my junk, and mill and logs, firewood, lumber....................
I could keep going.


Do you have two drain fields?

[Dan_Shade]

I have two runs of pipe buried about 10 feet from each other all from the same septic, pretty normal around here.

[Furby]

Yeah, that's one way they do it.
Here they tend to pull up the whole area to lay the pipes, leaves a large softspot in the yard.

[DonE911]

Well, I've done this before.... poured a slab over the drain field.  It was in FL which is very soft ground and the slab settled ad crushed the field...  I just put in a tee and took the field around the slab and everything worked fine again.

Will you even be able to pour the slab there without the officials going yahoo??

You could consider a pole barn and then put in a wooden floor. ( Timber frame would be nice and alot cheaper if you mill it as compaired to concrete)  That wont hurt your drainage and will be easy to insulate when you want to turn it into a kiln.  Not sure about your area, but I've never known anywhere to require a permit or anything for a pole barn unless you live in the city limits or a deed restricted area.

[FeltzE]

Normally the septic field must perk, that is to say drain to meete construction code the septic field is going to leak moisture in all directions but must... drain first. Pouring a concrete slab over top the field will not help it but shouldn't hurt it if the septic is in adequately drained ground.  Compaction shouldn't be any problem at all, less of a problem than parking your car on the current grass over top the septic. By placing a concrete pad over a large area you effectively evenly spread the weight of the concrete and the live load over the complete area, you are actually better off to pour a larger pad than required if you are concerned at all about compaction. Your car places 2 tons of weight on 4 spots on the ground measuring approximately 30 square inches each, divide that out and you will find about 16 lbs per square inch, park that same car on a 10 x 14 foot pad and your car weight is distributed to approximately .42 lbs per sq inch plus the weight of the concrete (guess at 1-2 lbs of concrete in a 1 sq inch by 4-6 inch thick pad maybe less) .... point being your resultant weight per sq inch is still only 2-3 lbs / sq inch...

Second, if you are pouring concrete for anything but a driveway you need to put a vapor barrier under the concrete. That keeps moisture from the underlying ground from wicking up through the slab to the interior of your future kiln, shop, or just making that cardboard box bottom fall apart.

Lastly, if in fact you have problems after the fact is there adequate room for you to reroute your septic field? If so, then roll the dice.

Best of Luck

Eric

[Furby]

Sorry Eric,
But I must disagree.
In order to pour a concrete slab, you must have compacted earth.
You simply do not want to compact a drainfield, and I'm sure you'll be bringing in fill if you try.
I've seen what can happen when a cherry picker drives at the very edge of a field, not pretty.
I've also driven a bobcat just a "bit" further, and it too wasn't pretty.
You are right that the field "should" perk, but as they get older, they don't unless in VERY good soil.
A pile of water is loss out the top. Why is the grass usually greener over one?
A lot of this comes down to type of field and type of soil, but for the most part, drainfields should simply be considered "greenspace".

[hardwood]

...I've never known anywhere to require a permit or anything for a pole barn unless you live in the city limits or a deed restricted area.

Welcome to Pennsylvania.

In our rural area, zone for agriculture, you need a building permit for anything, even an 8x10 prefab storage shed requires a permit and you must provide a plot plan showing where the building will be situated.

[Gary_C]

I have always believed that putting a vapor barrier under a concrete slab was a total waste of vapor barrier.  Concrete is absolutely NOT porous or it could not be used for swimming pools and water dams. You could not get water through intact concrete with a high pressure pump.

The water that appears on the surface of concrete slabs is actually condensation that forms because the concrete is below the dew point temperature of the air.  When you set something on a concrete slab and there is moisture under the item, it is because you have insulated that spot and it is colder than the surrounding concrete.

Save your vapor barrier for other uses.

[FeltzE]

Well then we must agree to disagree, 

In many places you will find building code requires a vapor barrier under concrete in structures. Concrete in pools and basements require a coating such as "Dry-Lock" a commercial concrete sealer used on both home basement walls, and pool interiors.

In areas with high water tables like Florida and Lousiana there are other issues to contend with, however in the stony state of Maryland, I would be concerned with drainage. High clay volume and stony soil may create an issue with waste water disposal forcing a high rate of evaporation rather than drainage.

Furby I've got to agree with you that the septic field should be green space if at all possible and that building atop of it should be only a last option.  Considering the compaction issue, again you should compact the soil to code prior to building and depending on where you build, you may have to  dig your footers to below the designated frost line. But for this purpose you could build a "floating slab" without any additional compaction of the surface, essentially you build your form boards to the slab size digging only enough to develop your desired sill thickness tapering the interior bottom of the slab from thinnest in the center to the thickest at the sill in a parabolic curve. By forming the bottom in a slight curve arching more steeply at the sill you reduce the stress points, create a strong sill where the slab takes a pounding and avert compaction issues by minimizing the disturbance of already setteled dirt (assuming there is no fill required).... it's a technique I've seen work in both western New York and her in North Carolina. The final slab is free of connection to the building structure allowing for frost heave or settling. The key is to ensure that the building is framed seperately to the slab. This can work well for a pole barn or shed but is not suitable for a home structure.

Even if you have good drainage I would spend the $10-$20 on putting down 4 -6 mill plastic sheeting as a barrier. Don't use a "home wrap" product like Tyvek because they will wick moisture to some degree and are designed to reduce airflow through the structure.

I must quantify my certification for these comments, I am a graduate of ....
School of hard knocks.
Beer hall of fame awardee
Certified S@@t House Lawer
Brown Belt in Office Debate


Eric

[Ga_Boy]

I must quantify my certification for these comments, I am a graduate of ....
School of hard knocks.
Beer hall of fame awardee
Certified S@@t House Lawer
Brown Belt in Office Debate


Eric

Eric,


Now that is funny!!   My sides is killing me!!!





Mark

Qualified Sea Lawyer

[FeltzE]

Thanks Mark,

Always can use some Navy support, I'm sure that after you get down here to visit you will tell the awful truth of my operation to the FF members. ... That is I'm also homeless, and only wish I had a sawmill...

Eric

[Dan_Shade]

I'm gonna move the location, my ground has a lot of clay, and probably barely perced as it is, the grass is definately greener there, that's how I figured out where the drainfield is located.

I went to enjinearin school, but i've long forgotten all of that stuff!

I too am a brown belt in office debate, in fact i'm so good at it, I sometimes find myself arguing against my original point!

[Gary_C]

No need to disagree with me, just stating my opinion. If you wish to follow the code and bury plastic or your money, go right ahead. Nowdays it's less trouble than burning. No one should know for a long time.

The reason they coat pool walls is the chlorine in the water will attack the cement and some of the aggregate in the concrete. Also basement floors need sealer because they usually pour a "basement mix" that has so much water in it that it can be poured in one corner and it will level itself. That concrete tends to flake and you can constantly sweep up powder so it needs to be sealed.

Just MHO     

[wiam]

If you have been inside of a hydro-electric dam you would realize that concrete was porous.  Water just runs in through the walls.  Kind of freaky with 80 feet of water on the other side.

Will

[Gary_B]

  Dan,
   Sounds like you have a bit of a problem there, being a native of Southern Maryland and as strict as the building codes are now days, I think you had better find another spot for that concrete slab, no doubt about it you sure dont want to build it over a leech bed or anything to do with a septic system. And second of course as soon as the concrete truck pulls up to your place in Lexington Park , the neighbors will be calling Leonardtown, and the building inspector will be out, then thats when all the problems start...... I remember years ago how so many people down there thought they were pretty slick by cheating on the perk test and now so many Septic systems do not function properly. Just take a ride down to St. Georges Island, Piney Point, Point Lookout, where the homes are about at sea level.. I know some of these areas have city sewage now....but those homes were built way before than.
                                                                       Gary

[Dan_Shade]

I'm a bit out of the way, i'm not too worried about snitches, but you're right.  I've decided to definately not put this thing over my drainfield.  concrete truck?!??!! my buddies work for beer, we're mixing!

i know the guy behind me, his lot barely perced when he built.

Is there a huge advantage to having a slab?  at this point, I think i'm just going to move it into the woods where it's pretty level. 

My lot is pretty flat, and has quite a bit of clay, i'm not sure how well it would actually perc now.  A lot of houses built when mine was built (1990) have mound systems, to my understanding, the county no longer allows a mound system for drainfields.

[Gary_B]

  Dan,
   Im not sure if there is a big advantage on a conrete slab., I am just a small operater, and I try to keep the overhead down on what ever I do.  When it comes to my air dry, I built platforms about 16 inches off the ground using locust for the legs, and a deck consisting of 2x4 on 12 inch centers, this gives me a nice level deck, I have built a few, One platform I keep all my 10ft. lumber, and the same with smaller lenghts. When I take a tree down, I try to keep the log lengths as standard as possible, although that can be a problem, due to straightness. From what I understand the codes have really changed in SM, the amount of land you can build a house on and so on. I was down there 2 weeks ago for a funeral and it has really changed, all the homes being built are 2500sq ft. or bigger., most are 2 story's . I will be making the trip once again on Thursday, trying to get in as much fishing in and spend time for with the family.

[Dan_Shade]

yeah, it has exploded in the past 5 years.  dummy me has been here 7, but refused to buy a house for 6 of them...

I could have had 15 acres 6 years ago for what I paid for my place.

why 16"?  i was just going to stack them on top of the cross ties that I have, that's about 8" up.

[logmason]

Quick story about crete slabs. Worked a big job for a homeowner in the city. They asked if I could seal a concrete deck I told them I would try. The deck is open on top with a garage under. The garage was a damp musty wet place, dripped in rain. I mixed linseed oil and mineral spirits 50/50 and sprayed about 5 or 8 coats on the slab. No more leaky. It is my opinion that concrete does not seal water. I have other for instances.

Also I am not a fan of dry lock. I do like cam coat on walls, comes in a bag and you mix with water and brush on.

[Furby]

Dan,
Most people raise their lumber stacks up for a couple reasons.
One is to get away from the ground moisture.
Also to be able to clear weeds easier and allow better air flow both through and around the stack.
It also helps to keep pests away, just a bit.

There is a couple VERY good posts on this subject someplace..........
Here we go! This is just one of them but you get the idea.
http://www.forestryforum.com/board/index.php?topic=4307.0

Read down, there are pics as to how to set it up.
Some use concrete blocks instead of the first cross tie.

[FeltzE]

On an interesting note, This morning on This old House they were pouring a concrete 6 inch thick floor, as a vapor barrier they were putting down 15 lb felt paper and on top of that a plastic 6 mil sheet.


The reason for the barrier is to keep moisture from migrating through the concrete floor to the interior floor above potntially damaging the interior flooring.

Eric