In most cases, sanding an old deck before staining it is necessary to achieve a decent finish. If your old deck has a relatively new stain finish on it and you're only doing touch-ups, you can generally skip the sanding part. However, if your goal is to make the deck look and function better, sanding first is a must. 

Yes, transforming a deck into a sunroom is an absolute possibility. Building a sunroom involves framing in the deck area with walls, adding windows, and affixing a roof. This project is not an easy task, but it does provide a stylish addition to your house. Not all deck designs support this type of renovation project, so consult a professional deck builder before beginning.

Generally, a patio is more accessible than a standard deck because patios are constructed at ground level. However, decks can be made accessible by adding a wheelchair-accessible ramp, a vertical lift, or a stair lift along the entry. An ADA-compliant deck ramp costs about $3,000 on average. The additional investment will provide a much friendlier experience for your guests with movement impairments.

It is possible to pressure wash your deck, but it’s usually best to leave the work to a professional for two main reasons. First, power washers are expensive, and you can avoid high upfront costs by hiring a deck washing pro instead. Second, you must be careful to use the correct setting to avoid damaging your deck material. You can only clean soft woods like pine with a wide spray and a low pressure; otherwise, the water will leave unpleasant marks on your deck. Hard woods, composite material, and metal can stand up to increasingly higher water pressures.