To maintain a wet edge, start near a corner and run the roller up and down the full height of the wall, moving over slightly with each stroke. Move backward where necessary to even out thick spots or runs. Don’t let the roller become nearly dry; reload it often so that it’s always at least half loaded. Keep the open side of the roller frame facing the area that’s already painted. That puts less pressure on the open side of the roller, so you’re less likely to leave paint ridges when doing DIY wall painting.
I hired this person because he was listed on Angie's List. This man claimed he took and passed his contractor's license test after he signed me up for a project (Feb.) that included fixing cracks, painting, repairing a gate, installing a screen door, etc. He said he would charge me the original "handyman" prices. He postponed the start date, brought one worker who fixed a few cracks, repainted the gate terribly, but ruined a dining room ceiling when his worker used silicone in a tube instead of the expansion tape, spray ceiling covering, and paint I had purchased saying this silicone was "better". Then they said they would have to paint the whole ceiling and charge extra. They left holes in the walls and did a sloppy paint job in several places. I just paid them to get them out of my home as I felt intimidated as a senior citizen who is handicapped. I will try to have the main guy come back when I let him know what I need redone. Don't know if he will come back without charging me more.
Before the scrubdown, protect nearby plants by misting their leaves and saturating the surrounding soil with water, pulling them away from the house, and shrouding them in fabric drop cloths. (Plants will cook under plastic.) Lay more drop cloths along the base of the walls to collect any falling paint debris. Walls should be wet down before getting scrubbed, then washed with a gallon of water mixed with 1 cup chlorine bleach and 1 cup of either a concentrated, phosphate-free cleaner, such as a trisodium phosphate (TSP) substitute, or Jomax House Cleaner. Working in sections, from the bottom to the top, will avoid streaks. Be sure to rinse walls well before the solution dries. Wood siding and trim should be ready to paint after a day or two of dry weather.
To paint a large section without leaving lap marks, roll the nearly dry roller in different directions along the dry edge, feathering out the paint as you go. After completing the entire length of the wall or ceiling, move to the next section and paint over the feathered edges. For the second coat, apply the paint in the opposite direction. This crisscrossing paint application sharply reduces (if not eliminates) lap marks.