How to Install a Hot Tub
If you have ever laid an outdoor patio or decking and hooked up an indoor washing machine, you are well placed
in knowing how to install a hot tub. Having said that, although installation is a breeze to the above average
diy'er, it still requires a lot of planning.
The first decision you will have to make is where to site your new hottub. Do not place the tub within ten feet
of overhead power lines and ensure that the proposed installation meets all city and local safety codes. There
needs to be adequate space for installation, plumbing and enough access to get the unit into the outside
Hot Tub Base
Depending on the layout of your garden or back yard, the installation choices will vary from a simple gravel and
sand base to araised platform. What you don't want to do is half heartedly level a piece of ground and plonk the
tub on it.
For on ground installations, a concrete pad is an ideal base, especially from a stability standpoint. However,
there are many other types of satisfactory on ground bases that can be installed.
Provided that there is enough space, fitting the hot tub into or on a decking area is one of the most
esthetically pleasing and practical installations. The hottub can be recessed down into the deck either partially
Start by measuring the base of your hot tub, then add two feet around each side for access. Multiply the base
width plus the additional four feet, by the base length plus the extra four feet. That calculation will give you
the total area occupied by the installation.
The next step is to find out how much water your tub holds. Although you can calculate the volume, most
manufacturers will provide this figure in the specs. A gallon of water weighs around eight pounds making the
overall weight of an average filled tub about 5,500 pounds. If you then add the combined weight of four people,
that brings the overall figure to around 6,000 pounds on average. It is therefore important to ensure that the
mounting surface can support that weight over the area of the tub.
For ground installations, you will need to level the surface with a rake and a long four by two, ensuring there
aren't any sharp stones or debris that can puncture the underside. If your tub has a wooden skirt, you may not have
to do anything more than lay some weed membrane over a bed of sand.
Raised Hot Tub Platform
A raised wooden or concrete platform framed by an outdoor landscape, helps to increase the beauty of your hot
tub or spa. It also helps to prevent moisture buildup around the base, which in turn can lead to mildew and wood
Once again, the key is to ensure you have a level surface and that it can support the required weight over the
whole area. The pressure on a surface is the force, in this case the weight, divided by the area. It's the pressure
that really counts and not just the total weight.
Laying concrete platforms that are both strong and level requires some degree of skill and patience, but it
should be well within the capabilities of most diy'ers. You'll need to build a suitable retaining box to pour the
concrete into and you should follow the guidelines laid down by local building codes.
A wooden platform is both attractive and fully capable of supporting most tubs. A series of a dozen 6 x 2
tannelised timbers laid on edge, bordered with further 6 x 2's and attached via good L-braces on a platform of 4 x
4's can support a medium sized hot tub safely. 4 x 4 timbers could be used for the entire platform, but this would
of course make the whole platform lower by the two inch difference.
Lay out the grid on level ground, ensuring the spacing is compliant with local building codes. Generally the gap
between joists should be no more than 12 inches. Boards can be attached via bolts and nuts through pre-drilled
holes, or via strong L-braces.
Even an empty hot tub weighs in at several hundred to a thousand pounds so you wil several strong helpers to
manauver the tub into position.
Hot Tub Electrical Wiring
Most wiring jobs, to run the controls, lights and pump are best carried out by an electrician. However, if you
are confident in your own abilities, you can do the electrical wiring yourself.
Run PVC conduit from the junction box in a trench that is at least 18 inches deep. Use an electrician's fish
tape or similar device to pull the cabling from the 220 volt GFCI (Ground Fault Circuit Interuppter) protected
equipment. All 220V spa's must have ground fault protection by law and for safety. Connect the wiring according to
the manufacturer's instructions.
It is advisable to have your installation professionally inspected prior to filling the tub. You don't want to
have to drain the tub in order to fix something that is non-compliant. Apart from that, hottub cleaning chemicals
will not be very kind to nearby grass, and you will have wasted money in filling and heating the tub.
Now go and reap the rewards of all of your hard work and take a relaxing soak in your new hot tub - You deserve