The pad is the part of this project you are most likely to do yourself and the part most likely to be done wrong. It is also the single biggest factor in how long the building lasts. Here is how to do it properly with rented equipment and a weekend.
Size the pad bigger than the building
Extend the pad about a foot past the building on all four sides. That extra foot is not wasted; it catches roof runoff and drip line splash and keeps water from undercutting the edge of the pad and washing back under the skids.
So a 12×20 building wants roughly a 14×22 pad. Mark it with stakes and string before you dig anything.
Pick the high point
Walk the yard after a hard rain and look at where water goes and where it sits. Put the building on the high side. Washington County ground is heavy and it holds water at the surface, so a low spot will stay wet for days. If the only usable spot is low, plan to build the pad up higher and add a shallow swale above it to divert runoff.
Strip the sod, do not build on it
Scrape off the grass and topsoil down to firmer subsoil, usually three to four inches. Organic material decomposes and settles, and a pad built on sod will be out of level within a year. Compact what you expose.
Rock: base first, then top
The pad wants about four to six inches of compacted rock total. The best result comes from a crushed stone with fines in it, commonly sold as CA-6, road pack or crusher run, because the fines let it lock up and compact hard. Clean washed gravel and river rock look nice and will never compact; they shift under load and are the wrong product for this.
Put it down in two lifts rather than one. Spread three inches, compact it, then spread the rest and compact again. Rent a plate compactor. Driving over it with a truck is not compaction.
Level is a number, not an opinion
Check it with a long straightedge and a level, or run a string line across the pad with a line level, and check both directions and both diagonals. Aim for level within about an inch across the whole pad. A pad that is out an inch and a half across a 20 foot building will show up in doors that do not latch.
Slight fall away from the pad on the surrounding ground is good. Slope on the pad itself is not.
Consider a fabric layer
On heavy clay, a layer of geotextile fabric between the subsoil and the rock keeps the stone from slowly disappearing into the mud over the years. It is inexpensive and it is the difference between a pad that lasts fifteen years and one that needs topping up in five.
Order the rock early
This is the practical advice nobody gives. Getting a load of rock delivered and spread out here can take longer than getting the building, and an unfinished pad is the most common reason a delivery gets pushed. Stock buildings typically move in 1 to 12 business days and custom builds in 3 to 6 weeks, so start the pad when you place the order, not when we call you.
What we need on delivery day
Pad done and level, roughly two feet of clearance past the building width along the whole path in, about 13 feet of overhead clearance, and firm ground for a loaded trailer. Deliveries run Monday through Friday. Full checklist on our preparing for delivery page.
Concrete instead?
Concrete is the ultimate base and the most expensive. It is worth it under a vehicle or a shop you will finish out. For everything else, a properly built gravel pad is what we recommend and it will outperform a poorly poured slab every time.
Get Started on Your Okawville Building
You do not have to drive to a lot to get moving. Use our 3D Shed Builder to pick your size, siding, colors, doors, windows and add-ons and see the building take shape on screen. When it looks right, send it to us and we will confirm pricing and a delivery date for Okawville.
Prefer to talk it through? Call our main office at 618-518-5578. We will walk you through building styles, custom options and rent-to-own and financing, and answer anything on our FAQ page. You can also see what we serve nearby on our location page.
