Ask the Carpenter: Patch vinyl siding, remove cedar shingle stains

Ask the Expert
A worker installs panels beige siding on the facade of the house Adobe Stock

Q. I have a house with vinyl siding that has holes and cracks in some places. How do I fix them?


A. Patching vinyl siding is easy with the right tools. If you have vinyl siding left over from the original installation, then it’s easy to get the replacement stock. If you don’t, take a sample of what you have to a supplier to find a match. The problem with patching in new siding is that the older stuff will have faded some in the sun. I recommend replacing larger sections so the repair is not as noticeable.

Vinyl siding is installed with roofing nails through a nailing strip. Each course interlocks with the next. For example, the bottom of the top course is locked into the nailing strip of the course below it.

To remove a damaged piece, you need to take out the piece above it. To do this, slip your hand into a seam between the damaged piece and the one above it. Pull and release the siding from the nailing strip. Use a “cat’s paw’’ — a nail puller — to remove the nails in the nailing strip of the damaged siding, then release the damaged piece.

Measure, cut, and insert a new piece of siding into the nailing strip of the course below it and then nail it loosely to allow for expansion and contraction. Once all of the parts are in, lock it in place using a vinyl siding zip tool.

These stairs have significant settlement problems. —Handout

Q. Can I repair these stairs, or do they need to be replaced?


A. It’s difficult for me to say without inspecting them in person, but it looks as if you have major settlement issues. My guess is that you have inadequate footing o footing failure, frost heave damage, or concrete block deterioration. You need to rip out these stairs and have new ones installed with a proper footing, new concrete blocking, and with all of the hollow cavities filled.


Q. About three years ago, I put white cedar shingles on my house that were dipped in a natural preservative. They are turning black. I have heard of various cleaning methods — diluted bleach, pressure washing, etc. — but I don’t know which works best. I’m sure I’ll have to do this every few years. Do you have suggestions?


A. Cover your plantings, put on protective eye wear and gloves, and wash your house with a dilution of trisodium phosphate and bleach. Manually scrub the black mold and mildew off the shingles and then apply a new coat of oil when they are dry.


Q. I wanted to ask a follow-up to your column on cleaning composite decking (“Ask the Carpenter: Removing algae from a composite deck,’’ March 31). My deck is under several trees, and it doesn’t take long to look grimy again during the season. Once I pressure-wash it, can I seal it with something to avoid the ongoing maintenance?

LESLIE, Newton

A. People think composite decks are no-maintenance when in fact they are low maintenance. I am not aware of anything you can use to seal composite decking. If you are seeing tannin stains from leaves, apply a deck brightener that contains oxalic acid. Cleaning your deck with a pressure washer is still the easiest method.

Rob Robillard is a general contractor, carpenter, editor of, and principal of a carpentry and renovation business. Send your questions to or tweet them to @robertrobillard. Subscribe to our free real estate newsletter at