DIY Hot Tub Aggregate Pad

Aggregate or Granite is an ideal base for your hot tub! Here are a few reasons why!

1. Simple & Cost-Effective
2. Non-Compactable & Perfectly Level
3. Provides Drainage
4. Rock will ensure no pests can burrow underneath
5. Not a permanent structure; the pad can be removed for future renovations.
6. Can finish with pavers or decked platform.

MATERIALS

• ¾ inch CRUSHED AGGREGATE or ½ inch CRUSHED GRANITE  (No Sand or Fill & granite is easier to work with & more attractive) 
• 4x4 Pressure Treated Lumber  x 4
• 2 ½ “ Screws 
• Corner Brackets   x 4 
• Wooden Stakes   x  4

INSTRUCTIONS

STEP 1: Create your frame; the hot tub will sit on top of the rock inside the wood framework. 

Example: If the hot tub is 78x78 (that equals the acrylic measurement, so the bottom perimeter is typically smaller), create an inside box size of 80” and allow extra length for steps. Your box should be a rectangle; 80” inside measurement one way, then the front of the tub, or where you plan to put the stairs, you should allow an additional 27” for steps, if you don't plan to build any deck/platforms up to the hot tub.

STEP 2: Attach 4x4 pressure treated lumber together with corner brackets. Once your box is secured, lay it down where you want it to go. Spray-paint around the outside to mark the soil to be excavated after removing the box. 

STEP 3:  Remove approx. 3” of soil so that the 4x4 box will sit into the dirt but proudly above the lawn.

Note: You want to excavate dirt from the lawn's highest side first. There is always a little bit of a slope, so starting from the high side ensures you don’t end up going too deep. Try to estimate as you go what you believe looks flat; You can make adjustments in Step 4.

STEP 4: Now that you have a relatively flat hole, put your 4x4 box back inside and drive four wooden stakes into the dirt on the inside of each corner, tight up against the wooden box. The stakes will allow you to lift each corner individually and put a screw through them into the box. You’ll need to do this as you level the box. Once you have the box level, go around and put some of the rock under any parts of the box you have lifted to add support. 

STEP 5: Remove your wooden stakes and fill the entire frame with your crushed rock. Smooth out and tamp down to ensure there are no low spots. High spots are okay. Take a long piece of 2x4 that spans across either side of the wooden box. Next, use the 2x4 (having a partner helps) to scrape across the top of the box, pulling any excess rock with you. Do this both ways and even diagonally if you like. 

        You now have a level non-compactable base for your hot tub!!