Proper hot tub installation preparation requires that you arrange for the following three items prior to installation.
- Proper Electrical Circuit
- Proper Sized Gas Line
- Cement Pads/Foundations for Hot Tub & Equipment
The standard electrical requirement for our complete hot tub system is a 240 volt, 20 amp circuit including a white neutral wire and a green insulated ground wire that is required by code.
National electrical code requires that the wiring be in a metal conduit and must have a disconnect switch within visible distance from the pump. Local codes may vary by city and state.
A 30 amp circuit is required for our standard/basic complete electric hot tub system with a 5.5kw heater, but you’ll need to add an additional 50 amp circuit if you upgraded your tub heater from 5.5kw to11kws.
We recommend that you check with a local electrician to make sure that your equipment meets the proper amp requirements prior to adding additional jets, pumps or accessories such as an air bubble system.
Our basic gas powered hot tub system includes a 100k BTU heater and requires a gas line of sufficient size. Upgrading to a larger heater might require a larger gas line and it’s prudent to check with a local gas professional prior to upgrading. Please remember that gas lines should only be sized and installed by licensed professionals.
Cement Pad/Foundation Requirements for Tub & Equipment
As we mentioned earlier in the “Locating Your Tub and Equipment” section, you will need a concrete pad or foundations for the hot tub and a concrete pad or foundation for the hot tub equipment.
Our basic equipment package requires a concrete pad of 24″ by 54″, although it can be squeezed into a slightly smaller area if absolutely necessary.
If you must use a slightly smaller area, we recommend that you wait until you have the equipment in your possession prior to pouring your concrete pad.
The hot tub itself also requires a concrete pad or foundation to sit on. For stability and settling purposes, the tub itself should sit on a single solid concrete surface. Everything settles over time and just like the concrete slab under most homes, concrete settles but remains flat.
Tubs have successfully been installed on blocks, in gravel or on pier block foundations, but the settling process is much more likely to be uneven.
An uneven settling process can concentrate the stress on a single area of the tub causing premature cracks and leaks.
The minimum thickness safety requirement for a basic hot tub pad is 4″ thick reinforced concrete with a diameter of 6″ less than the diameter of the bottom of the tub. Therefore, a 5′ round straight sided wood hot tub would require a 4′ 6″ square pad.
The type of ground underneath the pad should be stable as well. If the soil has a propensity for expanding and contracting due to extreme freezing or scorching temperatures, you may be required to add concrete footings to stabilize the pad. Checking with a local contractor is an easy way to find out whether you need footings or not.
Sunken or semi-buried tubs have also become very popular and they are much easier to get in and out of.
A wooden hot tub easily be installed below grade with a few minor adjustments.
You will need to dig a pit large enough to accommodate the size of the concrete pad and build a retaining wall around the pad to keep excess dirt and debris from eroding and coming into contact with the tub itself. The retaining wall should be made of concrete, concrete block or ‘ground contact’ rated pressure treated wood.
Please make sure that you leave a minimum clearance of 12″, preferred clearance is 24″-36″, around the entire tub; a 5′ diameter tub requires a 7′ wide hole. This clearance allows you to pre-assemble the tub above the pit and then lower it into place.
Tub assembly requires a minimum of 24″ of total clearance around it for proper construction. You may also want to consider adding a sump pump in the pit depending on drainage and ground water.
Installing a hot tub on or in an existing deck is also quite popular, but most decks aren’t constructed to accommodate the weight of hot tub filled with water.
An average hot tub filled with water weighs in excess of 5000 lbs. before you and your friends jump in and we strongly advise hot tub owners considering tub installations on existing decking to check with a licensed engineer prior to beginning tub installation.