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Elexwiz · 06-01-2013, 08:10 PM

I'm thinking about putting in a Crusher Run parking pad for my motor home. 8.5 x 33 feet. Initially I thought 3" of compacted Crusher Run would be sufficient but after researching I'm not sure now. When I research parking pads I find that most people do concrete. While this is the best it's just not in the budget. I was planning on clearing the grass and building a perimeter of 2x6 boards. Then lay out the first 2 inches or so and compacting it with a power compacter. Then lay the next layer and compact, etc, until it's 3" thick.

Is this a good plan? Will it support the weight of the my 20,000 lb motor home? I suppose I could increase the thickness of the pad directly below the tires and jacks to 4 or 5 inches. Yes, I will be using jack pads under the jacks.

Another slightly related question. In my research I found several posts about putting a moisture barrier between the tires and concrete. I've never heard of this practice. I assume it's because as a tire sits it will dry out becoming porous. The moisture in the concrete would seep into the tire. Not a good thing. Here's the related question, would that same practice apply to Crusher Run or other compacted rock pads?

Thank you for your time.

Dogpatch · 06-01-2013, 08:22 PM

I think you'd be fine. Water would dissipate as the crusher rock is porous.
I have compacted pea gravel where I park.

vsheetz · 06-01-2013, 09:35 PM

I have a few inches of compacted DG for workshop driveway and RV parking. Has worked great for several years. I had a guy with a tractor w/box scraper prepare the area, spread the DG, and compact it. Cost a couple three hundred dollars and took him no time at all.

ctpres · 06-02-2013, 05:40 AM

Look into geo fabric, the stuff used in highway construction. It looks a bit like weed blocker but much thicker. Once the thickness of your rock, gravel, washout or whatever is determined in normal construction standards, you can cut it in half. Basically it allows water to flow thru but does not allow the migration of material into soil below - ie rutting. Even with geo fabric, 3 inches of any loose material sounds thin to me. If you live anywhere near Houston I will give you enough for your parking pad. Also look into washout concrete for your pad. If available in your area it would be a great pad.

vsheetz · 06-02-2013, 07:33 AM

Quote:

Originally Posted by ctpres

Look into geo fabric, the stuff used in highway construction. It looks a bit like weed blocker but much thicker. Once the thickness of your rock, gravel, washout or whatever is determined in normal construction standards, you can cut it in half. Basically it allows water to flow thru but does not allow the migration of material into soil below - ie rutting. Even with geo fabric, 3 inches of any loose material sounds thin to me. If you live anywhere near Houston I will give you enough for your parking pad. Also look into washout concrete for your pad. If available in your area it would be a great pad.

washout concrete? how does that work?

Elexwiz · 06-02-2013, 08:38 AM

Quote:

Originally Posted by vsheetz

I have a few inches of compacted DG for workshop driveway and RV parking.

Appreciate the responses. One of the things I love about this forum is the proliferation of acronyms! Feels like I'm back in the Navy.

What is DG?

Dogpatch · 06-02-2013, 08:50 AM

Darn Good?

BFlinn181 · 06-02-2013, 09:59 AM

Three inches sounds much too thin for an RV parking spot. 6 inches of concrete is about minimum for a parking spot, and that's with a good firm base. Going short now will only cause issues later. Check with the town engineer to find out what they recommend for your local soil type.

rgvtexan · 06-02-2013, 10:39 AM

DG=decomposed granite. Or it did when I was in S. Cal.

Elexwiz, What is the location, frost line and soil type for this pad?

I am in North Eastern WA on the shores of Lake FDR. Sand/sandy loam, frost~18". My driveways are 5/8- crushed basalt ~4"-6". They have stood up well for 13 years.

vsheetz · 06-02-2013, 12:23 PM

Quote:

Originally Posted by Elexwiz

Appreciate the responses. One of the things I love about this forum is the proliferation of acronyms! Feels like I'm back in the Navy.

What is DG?

DG=decomposed granite.

charliej · 06-02-2013, 01:28 PM

You could still use some concrete, either two long runners, with choice of filler between, or four concrete pads with choice of filler between. This may help with ruts or sinking over time.

MSHappyCampers · 06-02-2013, 01:34 PM

Around here "crusher run" refers to very fine limestone, which is VERY dusty, getting white dust all over anything that stirs it up. Hope what you are looking at is different!

Good luck, happy trails, and God bless!

EngineerMike · 06-02-2013, 02:27 PM

Crusher run will vary depending on the crusher, rock source & handling. Around here its 3-6" w/some finer stuff mixed in. YCMV- your crusher will vary. A graded mix might be better- 3/8 to 1.5", or road base compacted with some 3/4" crushed over that.

To do this right the first time (i.e. most cost efficient), some considerations are in order.
3" is too shallow beneath the tires. 6" is about right. You could do 3" trenches below tires then 3" more over that to get a "pad". Or you could just do the tire tracks & mow or weed-kill the rest.

The real trick is the dirt below the tire tracks. For your mix not to get pushed down into the dirt you need proper "subgrade preparation." That means compacting usable dirt below the new gravel surface so it will withstand the heavy rig's weight. You can dig out two trenches & recompact appropriately; I'd go 12" deep for a project like this. If your existing dirt is sand, it should go back in 2" lifts & use a vibra-plate; if loam- 4" lifts w/a "whacker"; if clay- lime treat or put it elsewhere & put in Class 2 road base or highway sub-base material & a whacker. If its sand you will need some geotextile as mentioned above; if other, the geotextile is great insurance & additional support.

To get a handle on your local soil, get a quick tune up on the Unified Soil Classification System. Then google: "soil ribbon test" to see videos & websites explaining how to classify your dirt. Takes a little practice, but if you want your installation to last it will be well worth the effort. This is well within a clever DIYer's capacity.

Elexwiz · 06-02-2013, 03:04 PM

I'm in Southeastern Virginia, Chesapeake to be exact. Our home was built on good old fashioned Chesapeake Clay! I'm convinced that Hell is built on the same clay. In 2005 I made the mistake of trying to use a post hole digger for our deck. After 2 hours digging out 2 holes 18" deep I threw in the towel and rented a one-man auger. Still took over 3 hours to dig the other 11 holes. My point is that my subsoil is very strong. We don't really have a frost line. I put my pool piping (pvc) only 4" down and never had a freezing problem in 8 years.

I appreciate the suggestions. I will look into using concrete pads for the wheels and jacks, then crusher run the rest. I want the entire pad area devoid of grass and weeds.

I'm trying to balance an economical solution with a long lasting one. I appreciate everyone's comments and suggestions!