Q: I have a screened porch that has a funny ceiling: exposed rafters that are level for 12 inches at the eaves and then rising until they meet a steeper roof. What can I use to cover the rafters? I would like to use grooved unfinished 4-by-8 plywood paneling. Would that work? How can I paint it?

Install the paneling so that the grooves are parallel to the side walls. Cut short pieces to fit that 12-inch flat part, and then put full panels on the slanted part so the grooves line up. If the rafters are spaced properly, you’ll be able to nail onto the rafters, even at the edges. It should work well. The only bad part of the project is working overhead.

But there is one important thing you have to do first. Ventilate that space between ceiling and roof. Before you put up the panels, make sure there is a 2-inch-wide screened gap in the middle of the short paneling going the full length of the room, and another gap about 6 inches from the top of the ceiling, going the full length of the room. That will allow fairly good venting.

You mention the outside has a solid-color latex stain. Use that to paint the ceiling. If you have difficulty nailing well on the rafters, nail 1-by-3 strapping across them, 12 inches apart. That way you can nail into the grooves for an invisible connection, and nail anywhere into the strapping.

Q: Water was spilled on my kitchen tile floor, and now a fungus is growing on the mortar in the 1/4 inch gaps. How can I clean it off and keep it off?

Use straight bleach, let it set a few minutes and scrub with a small scrub brush. Repeat as necessary. When the grout is clean, seal it with a tile sealer. Those gaps are too wide. It is best to make the gaps 1/16 or 1/8 inch wide. That way grout will not show the dirt or change. You can’t fix the present floor, but any future floor with large ceramic tiles should have those thin gaps.

Q: I’m thinking of putting up a fence and was told I need to call a surveyor to locate the border. Some estimates exceed $1,200. Is that the norm?

Surveyors can be expensive because their skills are costly. One way to avoid such expense is to confer with your neighbor(s). They may be cooperative, and you can put the fence 1 foot in from the border line. But neighbors change, and you might see a curmudgeon move in and sue you if the fence does not comply. So find a surveyor.

Q: I bought my house last June. I recently saw a group of small holes in the wood on the outside. I can stick the point of a ballpoint pen in the holes. What are they and what can I do?

I think they are powderpost beetles, which tunnel in the wood and kick out a very fine powder-like sawdust. The holes are probably exit holes for the beetles, which are long gone. They also might be the old house borer. Such beetles often come and go. Or you can have an exterminator use insecticides to battle the critters.