Yes, it is possible to add an under-deck drainage system to an existing deck by retrofitting it to the structure. This process may require some prep work. For example, many drainage systems are installed on top of the deck joists, which would require you to remove the decking boards and railings first. To avoid this, you could opt for a below-the-joist drainage system. For best results and to ensure proper installation, it is recommended to consult a professional. A pro can inspect your deck, make any necessary repairs, and then install the drainage system correctly.

The least expensive way to build a pool deck is with concrete deck blocks, pressure-treated lumber, and the appropriate hardware for hanging joists and securing deck boards. With these basic yet durable deck materials, you'll have a pool deck that's built to last without the high price tag. You should also stain or seal the deck to protect it against the elements.

Ideally, a gate should be able to swing both in and out. However, if it can only open in one direction, it is generally best for it to swing inward. This is often the safest option, especially for deck gates near steps, as you'll want the gate to swing away from the stairs. An inward swing also prevents the gate from opening into a public space, like a sidewalk, and can be more convenient when carrying heavy items like a wheelbarrow into a garden.

There are exceptions, however. The layout of your property may require a different approach. For example, if your property is on a slope, the gate may not be able to swing inward. You should also ensure the gate can open fully without colliding with any objects or blocking access to other areas. For a backyard garden gate where public access isn't a concern, the direction it swings is largely a matter of personal preference. Finally, always check your local building codes, as they may have specific requirements for which way a gate must swing.

Building a deck isn't too hard if you’re handy with carpentry, have the necessary tools, and are willing to put effort into it. However, other factors, such as plans, permits, and design, can be hard if you don’t have experience in those areas.

Note: You’ll need another person to help you build the deck (especially for framing and setting the beams). Building a deck yourself will be very difficult if you don’t have an extra set of hands to help.