Q. My car leaked oil on my asphalt driveway. How do I remove the spots?

RICK POZNIAK

A. If the stain has set in, there’s nothing you can do short of sealcoating. If it has not, try this:

1. Wipe up excess with an absorbent cloth. Cat litter works here, too.

2. Sprinkle powdered laundry detergent or baking soda onto the stain.

3. Add water.

4. Scrub stain with a stiff brush.

5. Let sit for a half-hour and wipe off with a rag.

6. Rinse with a hose.

Q. My 20-year-old vinyl wallpaper was installed over blueboard that had been covered with a flat white paint. I have steamed off the paper but am left with backing and lots of adhesive. The surface is very rough, and it is very labor intensive to remove all of the residue. Could I apply a skim coat of plaster to make the surface smooth enough to paint? I have been dinging up the wall in my efforts to remove all remnants of the wallpaper.

CHUCK, Wakefield

A. Yes, you can apply a skim coat, but first, put on one coat of Bulls Eye 1-2-3, a water-based primer, over the area where the border was. After this has dried thoroughly, run over that section of wall with a six-inch putty knife to scrape off anything that loosened up and to get the area relatively smooth. After that, apply a skim coat of Durabond 45.

Q. My son bought a home in Methuen. The shingles on the back by the deck and on the shed are rotted and punkie. When I replace the shingles, should I put a ledger board down on the deck and along the roofline of the shed before reshingling? What are the best shingles to use?

I’m 69 years young and a retired carpenter. The last time I worked with shingles was when I was an apprentice, at 22. I have the practical skills, but I’m not certain how to do this the proper way. I want to do this right for my son.

THOMAS VITTORIOSO, Maynard

A. Your idea to add ledger board is a good one. At first, I was thrown off by the term. I’m pretty sure you mean a trim board that replaces the lower first or second course of shingles. I often see this on decks and even rooflines where folks need to replace the flashing and then cover it back up with trim. The pro to using this method is you can access and service your flashing. The con is it changes the look of your siding. It’s an aesthetic decision, but just make sure you add drip Z-flashing above your trim board. It keeps water from getting underneath. I’d use the same type of shingles that are on the house now. Most likely they are either white or red cedar.

Rob Robillard is a general contractor, carpenter, editor of AConcordCarpenter.com, and principal of a carpentry and renovation business. Send your questions to homerepair@globe.com or tweet them to @globeaddress or @robertrobillard.