An RV pad is one of the most demanding concrete applications a homeowner can install. Unlike a standard driveway that experiences dynamic loads from moving vehicles, an RV pad supports a static concentrated load from an RV parked in the same spot for days, weeks, or months at a time. The sustained weight of a fully loaded Class A diesel pusher motorhome at 30,000 lbs GVWR, sitting on 3 axles over a 40-foot parking area, creates very different stress patterns in the concrete than an 8,000-pound SUV that parks briefly and drives away.
The four RV classes in this calculator reflect the four distinct weight categories that American homeowners typically install permanent pads for. Class B camper vans at 11,500 lbs GVWR sit at the lighter end of the spectrum and can use 4-inch concrete in a pinch. Class C mid-size coaches at 14,500 lbs GVWR and 5th wheel trailers at 20,000 lbs GVWR occupy the middle range. Class A motorhomes, particularly diesel pushers, can reach 30,000 lbs GVWR and represent the highest load case for residential RV pads, requiring 6-inch concrete with rebar reinforcement.
The load analysis panel in this calculator shows the GVWR for each class, the per-axle load, and the distributed pounds per square foot on the pad surface. It automatically recommends wire mesh or rebar based on the vehicle class. These are planning guidelines, not engineering specifications. For a Class A motorhome pad or any installation on questionable soil, a structural engineer review is worthwhile before pouring.
Most RVs measure 8 to 8.5 feet wide at the body. However, Class A and Class C coaches commonly have one or two slide-outs that extend 2 to 3 feet beyond the body on the living room or bedroom side. A 12-foot-wide pad with the RV centered leaves 1.75 feet on each side, which is sufficient for slide-out deployment but provides minimal walkway space. For a permanent home RV pad where the vehicle will park regularly for long periods, 14 feet of pad width is the more comfortable standard. Our presets use 12 feet for Class B and C and 14 feet for 5th wheels, which reflects common real-world practice, but you can adjust the width field to match your specific site and slide-out configuration.
Square footage equals length multiplied by width. Cubic feet equals square footage multiplied by depth in feet. Cubic yards equals cubic feet divided by 27, multiplied by 1.10 for the standard 10% waste factor. Bag counts divide total cubic feet (with waste) by ACI-standard yields per bag.
Many home RV sites include a separate small concrete pad for the electrical pedestal, sewer clean-out, and water hookup. This is calculated independently at 4-inch depth (since it bears only foot traffic and equipment weight) and added to the main pad volume. Toggle the hookup pad switch to include it in your total concrete order. Default dimensions are 4 x 4 feet, which is the typical minimum for a pedestal base.
The load panel uses the GVWR for the selected RV class. Gross Vehicle Weight Rating is the maximum permissible loaded weight of the vehicle including passengers, fuel, water, and cargo. Load per axle equals GVWR divided by number of axles. Distributed load per square foot on the pad equals GVWR divided by pad area. The reinforcement recommendation triggers rebar for Class A vehicles and 5th wheels, and wire mesh for Class B and C where loads are lighter.
Example 3 illustrates one of the key advantages of this calculator over basic concrete volume tools: the combined main pad plus hook-up pad volume lets you place a single ready-mix order covering the entire RV site in one pour. Pouring the main pad and hook-up pad on the same day with the same truck eliminates a second minimum delivery charge, which typically runs $150 to $300 on a short-load order.
How thick does a concrete RV pad need to be?+
The minimum recommended thickness for a concrete RV pad is 6 inches for Class A motorhomes and 5th wheel trailers. Class B camper vans and small Class C coaches can technically use 4-inch concrete, but 6 inches is the better long-term investment given the sustained load and the cost difference is modest. The reason RV pads need more thickness than standard driveways is static load: a driveway concrete slab sees a car drive across it briefly, while an RV pad bears the full GVWR of a heavy vehicle sitting in one spot for extended periods. Concrete under sustained static load is more susceptible to creep and eventual cracking than concrete under brief dynamic loads.
How wide does an RV concrete pad need to be?+
A standard RV pad should be at least 12 feet wide. Most RV bodies are 8 to 8.5 feet wide, and a 12-foot pad provides approximately 1.75 feet of clearance on each side for slide-out deployment and entry step use. For RVs with full-length slide-outs that extend 2 to 3 feet beyond the body, 14 feet of pad width provides comfortable operating clearance. For 5th wheel trailers and toy haulers where the ramp door drops to the rear, leaving extra width at the rear of the pad is more important than side clearance. The 14-foot preset for 5th wheels in our calculator reflects this consideration.
How long should an RV concrete pad be?+
The pad should extend at least 2 feet beyond the front and rear of the RV when parked. For a 37-foot Class A motorhome, a 40-foot pad is appropriate. Adding the extra length at the entry end allows for the entry step deployment and a small landing area. Our presets size the pad for the full length of a typical RV in each class plus a few feet of margin. If you plan to place a small patio or seating area at the entry end of the RV, extend the pad by another 6 to 8 feet to create a continuous surface, or plan a separate patio pour adjacent to the pad.
Does a concrete RV pad need rebar?+
Class A motorhomes and 5th wheel trailers should have rebar, not just wire mesh, in their concrete pads. The concentrated axle loads of vehicles in the 20,000 to 30,000-pound range require the tensile strength of rebar to resist bending under load. Specify No. 3 rebar (3/8-inch diameter) on 18-inch centers in both directions, placed at mid-depth of the 6-inch slab. For Class B and C vehicles, 6×6 W1.4 welded wire mesh at mid-depth of a 6-inch slab is adequate. The load analysis panel in our calculator shows which specification applies to your selected RV class based on GVWR. This is a planning guideline; consult your contractor or a structural engineer if you have any question about the required reinforcement for your specific soil conditions.
Do I need a permit for an RV pad?+
In most US jurisdictions, a permit is required for any concrete pad larger than a certain size threshold, typically 200 to 500 square feet. An RV pad is always above this threshold and almost certainly requires a permit. Additionally, many municipalities have separate regulations about RV storage on residential property, including setback requirements from property lines, restrictions on how long an RV can be parked in a visible location, and requirements for screening from neighboring properties. Check with your local building department, your HOA if applicable, and your municipality’s zoning code before designing your RV pad. The HOA rules often affect placement and screening requirements independently of the building permit.
How much does a concrete RV pad cost to install?+
A professionally installed concrete RV pad in the United States costs $6 to $12 per square foot for a 6-inch slab with rebar and standard finishing. For a 12 x 40 foot (480 sq ft) Class A pad, the installed cost typically runs $2,880 to $5,760. Materials only (concrete ready-mix) for a 6-inch pad at $150 per yard runs approximately $1,601 for 10.67 yards. The rebar adds approximately $400 to $600 in materials for a 480-square-foot pad. Total materials including concrete, rebar, and forms run approximately $2,100 to $2,300, representing roughly 40% of a professionally installed pad price. The balance covers labor, equipment, and sub-base preparation.
What PSI concrete should I use for an RV pad?+
Specify 4,000 psi concrete for all RV pads. In freeze-thaw climates where deicing products may be applied or where winter temperatures cause repeated freezing and thawing, specify 4,500 psi with air entrainment (4 to 6% air content). The higher compressive strength resists surface scaling from freeze-thaw cycles and from the deicing salts tracked in on RV tires during winter. For Class A and diesel pusher coaches, some contractors specify 4,500 psi regardless of climate because the sustained heavy loads benefit from the additional strength margin. The cost premium for 4,500 psi over 4,000 psi is typically $8 to $15 per yard, adding roughly $85 to $160 to a 10.67-yard pour.
Can I pour a concrete RV pad in sections?+
Yes, a large RV pad can be poured in sections using a construction joint with dowel bars between pours. The typical approach is to form and pour one half of the pad, install 18-inch smooth dowel bars at 24-inch spacing at mid-depth of the slab along the joint location, pour the second half 24 to 48 hours later, and saw-cut the joint between the two pours to control any differential movement. This approach allows each pour to be completed with a single ready-mix truck load and gives the first section time to achieve initial strength before the second is placed. The construction joint should be located away from the tire contact zones of the parked RV to minimize load transfer demands at the joint.
What is a utility hook-up pad and do I need one?+
A utility hook-up pad is a small separate concrete slab that supports the electrical pedestal, sewer clean-out riser, and water connections for your RV site. It is typically 4 x 4 feet at 4 inches thick and placed adjacent to the main parking pad near the front or rear of the RV where the connections will be accessed. Without a hook-up pad, the utility connections are installed in the lawn or gravel, which creates a mud problem around frequently accessed connections. The hook-up pad toggle in our calculator adds the volume of this small slab to your total concrete order so you can pour both in a single ready-mix delivery, avoiding a second short-load delivery fee.
Can I use gravel instead of concrete for an RV pad?+
Gravel or compacted crushed stone can function as a temporary or lower-cost alternative to concrete for RV storage, but it has significant disadvantages compared to a permanent concrete pad. Gravel shifts under the sustained weight of a heavy RV, creating ruts where the tires sit. The RV leveling blocks sink into gravel, making leveling difficult. Moisture wicks up through gravel and into the RV underbelly. And the pad surface cannot be cleaned the way concrete can, making maintenance more difficult. Many HOAs and municipalities do not allow permanent gravel RV pads. For a site used occasionally, compacted crushed stone (recycled concrete or crusher run) with geotextile fabric underneath is the best gravel alternative, but concrete is the definitive long-term solution.
How do I prevent a concrete RV pad from cracking under a heavy motorhome?+
Four measures combine to prevent RV pad cracking: adequate slab thickness (6 inches minimum for Class A and 5th wheels), proper reinforcement (rebar at mid-depth for heavy vehicles), a well-compacted sub-base (4 inches of compacted crushed stone minimum on undisturbed or well-compacted native soil), and properly spaced control joints (saw-cut within 24 hours to at least 1.5 inches deep, on 10 to 15-foot centers for a 6-inch slab). The most common cause of RV pad cracking is inadequate sub-base preparation, particularly when the pad is built over fill material that was not compacted in lifts. A concrete slab is only as good as what it sits on.
What is GVWR and why does it matter for my RV pad?+
Gross Vehicle Weight Rating (GVWR) is the maximum permissible total weight of the fully loaded vehicle including the RV itself, passengers, fuel, fresh water, personal belongings, and cargo. It is the weight the manufacturer certifies the vehicle can safely carry without exceeding chassis, axle, and tire ratings. For an RV pad, GVWR is the correct weight to use for structural calculations because it represents the worst case: a fully loaded motorhome or trailer at maximum capacity, which is the condition the pad must support indefinitely. The pad load analysis panel in our calculator uses GVWR for each class preset to calculate load per square foot and provide the appropriate reinforcement recommendation.
How soon can I park my RV on a new concrete pad?+
Wait a minimum of 28 days before parking a heavy RV on a new concrete pad. At 7 days the concrete has about 70% of its 28-day compressive strength, which is sufficient for light foot traffic and positioning activities, but the sustained weight of a 20,000 to 30,000-pound vehicle should wait for full cure. In cold weather (below 50 degrees Fahrenheit during the curing period), cure time extends significantly. For a Class A motorhome or heavy 5th wheel, waiting the full 28 days is not optional. Placing a 30,000-pound vehicle on concrete that has only reached 60 to 70% strength under sustained static load is a real risk for cracking, particularly if the sub-base has any unevenness that concentrates load at specific points.
How many trucks of concrete do I need for a Class A RV pad?+
A standard Class A pad (12 x 40 ft, 6 inches thick) requires 10.67 cubic yards, which fits in a single standard ready-mix truck load. Standard ready-mix trucks carry 9 to 11 cubic yards. Confirm your local supplier’s truck capacity: if they load 9.5 yards per truck, 10.67 yards requires two trucks or a second short-load delivery. For a 14 x 42-foot 5th wheel pad (13.07 yards), two trucks are required. A good practice is to order 10% more than the calculated amount (already included in our estimate) and discuss scheduling with your supplier so the second truck arrives immediately after the first is emptied, preventing any cold joints from forming in the slab.
Why does the RV pad calculator use a 10% waste factor?+
The 10% waste factor accounts for concrete lost at the form edges where the slab transitions to the surrounding grade, any sub-base unevenness that increases actual slab thickness in low spots, concrete remaining in the ready-mix truck chute and drum after discharge, and the optional hook-up pad if included. For a large RV pad, 10% represents roughly 0.97 cubic yards on a 10-yard base order, which at $150 per yard is $145 of additional material. Running short on a large RV pour is costly: calling a second truck delivery incurs a $150 to $300 short-load fee and creates a cold joint in the slab if more than 90 minutes passes between pours. The waste factor prevents this outcome.
Can I add a concrete RV pad to an existing driveway?+
Yes, a concrete RV pad can be added adjacent to or extending from an existing driveway with an expansion joint between the two pours. The expansion joint prevents the new slab from bonding to the existing one and allows independent movement, which protects both slabs from cracking due to differential settlement. Use a pre-molded foam expansion joint material (not wood) between the two slabs, placed at the full depth of the new slab. The new pad should be poured at the same elevation as the existing driveway with a smooth transition. If the existing driveway is 4 inches thick and the new RV pad is 6 inches, excavate the sub-base 2 additional inches under the pad area to maintain consistent surface elevation.