How can I keep bees away from my deck?

First you need to find out what is drawing them to the deck. If you have flowering plants, you may want to move them further away. Check for a nest nearby. Bees are currently dying at an alarming rate and we need to protect the bees if possible as we need them to pollinate our food crops.

Use WD 40 spray around porch walls specially around corners of ceiling this will drives them away

They will always come around flowers -- or perhaps they have a hive somewhere -- check where they are going -- they could also be wasps -- there are several things at the garden centers to attract and trap them -- ask the hort person at your garden store.

If carpenter bees, saturate with termite spray. You will need to do it early spring and again mid summer as it dries.