Tiedown spot options?

FastEddieB

FastEddieB

Touchdown! Greaser!
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Lenoir City, TN/Mineral Bluff, GA
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Fast Eddie B
I need a place to tie down my Sky Arrow when we fly into our strip in TN.

We got a large area leveled for now, and need an area about 18'x18' that's solid enough to support the Sky Arrow, but hopefully something heavier as well.

I sank some cinderblocks to provide tiedown points. Here's how it looks now:

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Problem is the dirt is not very hard packed, and of course if it has rained its just muddy.

I got a quote for an 18'x18' cement slab. At just under $4k it was about triple what I was guessing.

Has anyone tried to firm up a tiedown spot with cinderblocks or pavers of some sort? Karen came across these ideas online:

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The plan would be to hire a fellow with a Bobcat, prepare a base with gravel, then the cinderblocks or pavers on top. Then filled with dirt and seeded. Don't think that would run over $1k or so all in.

Any thoughts?
 
No crushed limestone "road base" available in your area? Scrape down what you have and put down 6" of compacted road base and you'd be golden. Recycled asphalt paving (RAP) works well, too.
 
The bobcat would cost more than you are guessing I believe.
What is the cost of concrete per yard in your area? Have you ever done concrete work? It is pretty easy to form up an area you wish to pour. Doing it yourself should cost about what you were guessing in materials.
 
FORANE said:
Have you ever done concrete work? It is pretty easy to form up an area you wish to pour. Doing it yourself should cost about what you were guessing in materials.
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This is what I was thinking too. Home Depot sells QuickCrete relatively cheap. Just throw it in a 5 gallon bucket and mix it up with an auger. For as big of a spot as you’re needing it wouldn’t take much and it’s not too difficult.
 
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I’ve seen pavers bedded in gravel used. The roadbase suggestion would be fine too. Some parts of the country use a mix of sand and gravel as road base rather than crushed limestone. About three or four inches roadbase over compacted soil works well. Just use water and a blade to compact.

I’d go with something a little more substantial than a buried cinder block for a deadman but that’s just the engineer in me screaming about an anchor pulling lose.
 
I just had an $8K driveway poured this past week. Forming, leveling, tying rebar... that's hard work but doesn't require special knowledge. Pouring and finishing 7 yards of concrete? That requires special knowledge, strong muscles, and special tools.

My pour took 22 yards and averages 8" thick, but concrete is the cheap part of the total cost. The smaller the pour the higher the sq ft cost will be.
 

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Flop three rows (one short, two long) rows of patio blocks down on top of whatever is already there.

Done.
 
I would recommend installing some barrier cloth under the pad area, hauling 18-20 cubic yards(hopefully around $20/yard, depending on the market in your area) of crushed rock or recycled asphalt(as Stewart suggests), level it, then compact it with a walk behind compactor. Done.

I've never heard of the concrete block idea before. It could work, but It seems a bit of trouble to purchase, place, and level all of those blocks and I'm not sure what you would gain over a compacted pad of clean material..

Ryanb said:
This is what I was thinking too. Home Depot sells QuickCrete relatively cheap. Just throw it in a 5 gallon bucket and mix it up with an auger. For as big of a spot as you’re needing it wouldn’t take much and it’s not too difficult.
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An 18 ft square slab, 4 inches thick, would take 12 cubic yards of concrete, or 324 cubic feet. At 2/3 of a cubic foot of concrete per 5 gal bucket, that would be nearly 500 buckets to mix.
 
Dig a hole, get some rebar and concrete mix, place a hoop, pour concrete, cover with dirt or grass.

That's also a TON of money for that concrete work, I have a 9x28ish slab poured, complete with a slope, in floor drain and studs, think it was a hair over 1k cash.
 
edo2000 said:
An 18 ft square slab, 4 inches thick, would take 12 cubic yards of concrete, or 324 cubic feet. At 2/3 of a cubic foot of concrete per 5 gal bucket, that would be nearly 500 buckets to mix.
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I didn’t expect that he would do that for the entire slab. It was meant to be used on a spot big enough for the wheel base of his SkyArrow. What I envision in this based upon the photo, would take less than 10 buckets of ‘crete.
 
FastEddieB said:
I got a quote for an 18'x18' cement slab. At just under $4k it was about triple what I was guessing.
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Yeah that sounds high. Exterior concrete work, 5" to 6" thick, can be had around here for $5/sf and our mud is running about $100/yd for a 3,500 to 4,000# mix. Your pour is only 4 yards at 4" and 6 yards at 6". Are they hauling it in from Florida or something? :)

As someone said, a smaller project will cost a bit more but it definitely shouldn't be 2.5 to 3 times. If there's no excavation involved, three guys should easily be able to form and pour that slab in a day no bigger than it is.

Any chance of just sodding it to get yourself out of the mud? You could "quickcrete" some small squares for the tires to set on when parked so they don't leave ruts.
 
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Zeldman said:
Marston mat.... PSP..???
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Gawd I hated laying down PSP. We practiced covering crated hole in the runway.

This what we used, not sure it was called PSP though. The pieces interlocked and would be laid over or dragged over a damaged runway crater after it was filled.

th
 
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Perhaps some math revision is in order. The slab would be 324 square feet which at 4 inches thick is 108 cubic feet. At 27 cubic feet per yard this equals 4 cubic yards. Still at .66 cubic feet per 5 gallon bucket, it would take approximately 164 buckets. (a five gallon bucket is actually about .77 cubic feet, but you couldn't fill it to the rim) To do this in an 8 hour day, you would have to mix a bucket every 2.9 minutes. I've mixed much smaller amounts this way but I wouldn't want to take on that much under any circumstances.
 
Old used-up landing mats for an 18x18 pad would cost $1800.00 less freight. If those mats made any economic sense I’d have had a landing mat runway for the past 25 years.
 
FastEddieB said:
That's the plan, though everything is taking longer than we figured. Waiting for the final engineering study to be completed so we can get permitted.
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So how long a time frame are you looking for before the hangar? Is it temporary?
 
Too much area for a bucket job. But a lot of landscaping retailers and tool rental yards have 1/2 to 1 yard mixers that they fill and you can tow behind a pickup. That would be a better way to do a DIY concrete job of that size.
 
I wouldn't even bother trying to mix my own. That is too much work even with a powered mixer. Those bags are 80 lbs each or so if I recall. I would form it myself and call in a truck to just pour it. All in should be around 1k.
 
Yeah, would be better off getting it from a truck, Form it yourself, lay in 6x6 WWF (Welded Wire Fabric), have it dumped in by a chute, Strike it off, Float it, and give it a broom finish, You and a few friends could knock this out in about 4 hours. Remember to strike in a control joint every 10 linear feet, and you're golden. You can rent all of the tools at either Home Depot, or Sun Rental. If you were feeling really ambitious you could rent a bobcat yourself and do it, the learning curve isnt that great. Of course I did this while in the military, I ran heavy construction equipment, and my last stint was as an instructor at the U.S. Army Engineer School.
 
flyingfrog said:
That is AM2 mat.
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That sounds familiar but it's been a long time. They were maybe 2-3' wide and 12-15' long interlocking panels, something like that. Might have been aluminum but not sure about that either lol.
 
I had the muddy area in front of my hangar 'fixed' by having those pavers with turf installed 2 years ago. Worked great! Looks like a grassy entrance but no matter how wet things get, it's like having a well drained paved ramp.

Prepping the bed for the pavers is where most of the work is.
Can't speak to the cost because it was part of a larger job.
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Sent from my iPad using Tapatalk
 
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Rod Broberg said:
Perhaps some math revision is in order. The slab would be 324 square feet which at 4 inches thick is 108 cubic feet. At 27 cubic feet per yard this equals 4 cubic yards. Still at .66 cubic feet per 5 gallon bucket, it would take approximately 164 buckets. (a five gallon bucket is actually about .77 cubic feet, but you couldn't fill it to the rim) To do this in an 8 hour day, you would have to mix a bucket every 2.9 minutes. I've mixed much smaller amounts this way but I wouldn't want to take on that much under any circumstances.
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You are correct. I flipped from yards to to ft in my quickie calculation halfway through and botched it. 324 cubic ft would be the 18 x 18 slab, 12 in. thick, which would definitely be overkill. :) Still would be a lot of 5 gal. buckets to mix and pour.
 
Misc ramblings.

Another consideration to doing it with a home mixer or with bags of quickcrete is that you'll have a 1000 cold joints. Not to mention that the quality and strength of Quickcrete pales as compared to batch plant concrete.

Wire mesh: Don't waste your time with rolls of 6x6-10/10 (now known as 6x6-W1.4/W1.4 since they went metric). The 10 gauge wire isn't heavy enough to do you any good and the wire was laying on the bottom of 90% of the old slabs that I've demo'ed with 6x6-10/10 wire....this from the guys pouring the concrete "walking it down" as they're screeding, doesn't do much good there. 6x6-6/6 mats set on bricks (concrete bricks, not clay bricks) or rebar chairs are a much better option. this is now known as 6x6-W2.9/W2.9. It'll still get pushed down when the guys walk on it but it's heavy enough gauge to recover...IF it's adequately supported on bricks or chairs.

Rebar on chairs (min #4) @ 12" to 18" OCEW is better yet.

cutting concrete: Exterior concrete should be cut into SQUARES that are no more than 2x the thickness in feet. i.e. if you're pouring a 4" slab, cut it every 8'...if your pouring a 6" slab, every 12'. And the depth of the cuts, to do any good, must be a minimum of 20% the thickness of the slab. I cut them 25%. Concrete WILL crack as it cures and shrinks. The "control joints" are an attempt to get it to crack where you want it to crack...at the joints. So you're setting up a weak plane. The cutesy residential "concrete joint toolers" that you can buy at Home Depot or Lowes, and that only score the concrete about 1/2", are a complete waste of time.

Also, in warm weather the joints should be cut the same day that the slab is poured. In many cases, if you wait until the next day the concrete has already started cracking where it wants to.

Concrete should be poured at 5" slump maximum. Any wetter than this and you'll likely get shrinkage cracks and/or alligatoring on the surface. Plus the concrete will be weaker. Most concrete guys, especially the residential guys, want to pour it a lot wetter. Because it's a lot easier!

If you can avoid it, don't pour over visqueen. Visqueen keeps bleed water from exiting the bottom of the slab so all the bleed water must exit through the top. Thus, the top 1/2 of the slab experiences nearly double the slump before it starts to set...see above commentary about the importance of not pouring concrete too wet. Or, if you must pour over visqueen, lay the visqueen down and then put the standard 4" of gravel base ON TOP of it. At least this way there's 4" of semi-dry material below the slab to absorb some of the bleed water. This is more of an interior concrete thing, exterior concrete should (almost) never need visqueen.

Also, pouring over visqueen, especially if no membrane cure is used, will cause excessive curling of the slab since the bottom will cure far slower than the top.

Don't over-trowel exterior concrete. This brings too much paste to the top which weakens it. Bull float it off, trowel it just enough to bring enough paste up to broom. Then broom it, and walk away. If floating brings enough paste to the top to allow brooming then skip the troweling completely! Over-trowelling is another cause of alligatoring.

Use membrane cure! This significantly reduces curling and increases the strength. The slower concrete cures, the stronger it will be. Another option, especially on a small slab, is once the troweling and/or brooming is done, place a sprinkler in the middle and keep the concrete wet for two or three days. This is how concrete was cured in the old days before they developed the membrane sprays.
 
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Two thoughts: Plant grass and grade the area so water will run off; or rent one of those compactors and beat the ground until it is impermeable (you'll need to make sure you have a crown here as well)
 
Arrange for a truck to deliver the concrete.
Buy some lumber and rebar.
Rent (if you don't have them) the floaters and tools you will need.
Rent a big BBQ grill, buy a pig and announce a POA BBQ and work party.
 
Just now got the actual quote:

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The one thing I didn’t mention was asking for a slightly sloped “apron” to run up to the pad.

I’m going try to meet with a different contractor tomorrow to discuss lower-cost options.
 
What ever you decide, don't be this guy, a student pilot as seen at my home airport recently.
 

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retpd2001 said:
What ever you decide, don't be this guy, a student pilot as seen at my home airport recently.
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What’s funny is that I AM that guy!

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Without a tail brace, the logical way to secure the Sky Arrow is wings and nose. Cinch a tail tiedown tight and it just pulls the nose into the air.
 
Rebar in concrete slab does help keep cracks from separating but it has to be put on bricks or standoffs. The installers usually just put it in and stomp it so it does no good whatsoever lying on the ground and not IN the middle of the concrete. So if you specify rebar, specify how it is to be supported and tell the installers they will have to be tripping over it (thats why they dont like it). Then they will say yeah sure no problem and just throw it in and stomp on it anyway unless you train them how to do it right. Also, order you OWN concrete so you actually get the good stuff.
 
get "six bag" concrete, say that and they'll think you know what you are talking about.
 
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