Q. Can you tell me what to use on my wooden thresholds so that they won’t swell from heavy rainstorms?
A. Sure can, but I have to guess on what and where the thresholds are. There are two thresholds, one under an exterior door front and back. They are unfinished oak, and are exposed to weather because there is no roof over the entries. And maybe there are interior thresholds, one between each doorway, whether it has a door or not. The treatments are different. For the interior thresholds, two coats of an oil-based polyurethane varnish will do well to keep the moisture out. Since your interior thresholds swell, it means that the house air is humid during heavy rains, so something should be done to prevent that. Winter heat will help a lot, and in summer, A/C or a dehumidifier will do it.
For the big, slab-like thresholds under exterior doors (front and back), apply one coat of a semitransparent stain. Such stains are penetrating preservatives, so only one coat will last five years or so, and will not peel. They come in earth colors, so take your pick.
Q. My wood-framed and -shingled house was built in 1900. The last time I had the exterior done, 20 years ago, I was told the house had been stained at the time it was built, and stain was then applied to the surface again. I am now about to get a new finish to the exterior. The house painter who will do the work plans to first apply a coat of oil-based primer, then finish with two coats of latex stain. Is it best to apply an oil-based coat over 100 years of stain? Is there any other surface treatment I should ask for?
A. Why put a primer over 100 years worth of stain? Find a painter who is familiar with stains, and don’t let anyone do any painting. I do know that a semitransparent stain will go over an old stain, but not a solid color stain, which is thinned-down paint. Don’t even think of paint, and when it comes to stain, it must be a semitransparent stain.
Q. Can you advise me how to control/eradicate trumpet vine that has taken over my and a neighbor’s backyard? Cutting it and/or pulling it out only makes it grow in other places, as it appears to be a vine that grows underground, and then puts up shoots.
A. Trumpet vine is like Japanese spurge, also known as Japanese bamboo, which grows underground to spread, and untreated, will grow ferociously. I don’t think it can be controlled, but must be eradicated. Everything, including underground growths, must be dug out completely. I got rid of my Japanese bamboo, but it took two or three autumns to do it.
Peg Sullivan sent this e-mail about flies: “We were always plagued with flies in August until I started keeping basil in the kitchen. Last year the only fly we saw was when my plant had died. It was gone on the same day I bought new basil.”
Well, thank you, Peg.Globe Handyman on Call Peter Hotton is also
in the Sunday Address/Real Estate Section.
He is available 1-6 p.m. Tuesdays to answer questions. Call 617-929-2930. E-mail him at firstname.lastname@example.org.