Scrub then refinish a waxed oak floor
Q. My floor is wide brushed oak that is stained and, I think, waxed. I am trying to clean it, but how?
TORI FARRELL, Wayland
A. I think your floor is sealed and waxed, a technique that dates back to the 1950s and '60s. It's a handsome finish, but the wax that is buffed must be removed and new wax applied and buffed every year or so. Who needs that? Wash it with detergent and water, and scrub with a scrub brush to get into the nooks and crannies of the brushed finish. This will remove any wax. Then apply new wax and buff it with a power buffer.
If you can't find the wax and/ or a power buffer to buy or rent, then finish the floor with a semi-gloss polyurethane varnish.
Q. I have to put grab bars in my shower. I can't use the suction-cup bars because they do not grab on the 2-by-2-inch tiles. I have to screw them into the studs, but I cannot find the studs. The wall behind the tiles is solid concrete. What should I do?
RUTH, Needham
A. If the walls are solid concrete, there are no studs. To make sure, you can drill a hole in the grout line to see if there is indeed solid concrete or a stud wall. Or, take off one tile and drill a larger hole. This can show you where the studs are if you look with a strong light, or if it is indeed solid concrete. If solid concrete, you can drive the proper-sized hole into the concrete to hold anchor bolts.
Q. We bought a wonderful house, circa 1919. The house inspector noted that based on the ice dam on the roof, extra insulation should be added in the attic. The attic has loose insulation that seems very old. Can I add insulation, or should the old insulation be removed?
NEW, in Hotton's chat room
A. You can add plenty of insulation on the floor, as long as there are no floor boards. Keep the insulation out of the eaves (the roof overhang). The old insulation is OK to keep. Adding insulation is only part of the solution. Snow and ice on the roof is not necessarily an ice dam, particularly if there are no leaks. Insulation will help make the roof cold, but more ventilation is also necessary. Install vents in the soffits (the roof overhang), and make sure there are vents in the gable ends, or install a ridge vent. A cold roof is the only protection against ice dams.
Q. We have artillery fungus marks on our vinyl siding, wood trim, windows, and storm doors. How can we get rid of the marks? We already removed and replaced the mulch near the house that was the likely source.
SARAH, in Hotton's chat room
A. Isn't that fungus amazing? It grows in wood mulch and fires those black spores as far as 15 feet; hence the name. If the replacement mulch is wood chips, the fungus will continue to grow. What you need is a mulch of crushed stone.
To get rid of the stubborn marks, pressure-wash them, but be careful not to get water behind the vinyl. Or, a strong detergent will do; so will Mr. Clean Magic Eraser.
Globe Handyman on Call also appears in the Sunday Real Estate section. He's available 1-6 p.m. Tuesdays to answer questions. Call 617-929-2930. Hotton (photton@globe.com) also chats online 2-3 p.m. Thursdays. Go to www.boston.com. 
