Q. My brick building was built in 1922, and the hall downstairs is infested with rats. These are not mice. They are constantly coming in. We’re hiring someone to inspect the foundation walls to check for holes. The foundation is about 5 feet into the ground. The building is surrounded by concrete sidewalks and alleyway. We also have a hall with hardwood flooring that is spongy in some places. Someone thinks the floor could be supported with wood sleepers on dirt; would that be an entrance for more rodents? How can the rodents be kept out? Many exterminators were no help.
DENNIS, SOUTH BOSTON
A. Rats are tough critters and reproduce like rabbits. They can climb great heights, burrow underground, squeeze through openings as small as 1/2 inch square, and swim fairly long distances.
There are two ways to contain rats and other rodents: Set snap traps to try to keep ahead of them, and fill all holes in foundation and basement floors to keep them out. Use snap traps where you can see them along runways and areas next to walls. Don’t use poison baits because the rodents will die in unreachable areas and will stink up the building. Or trap the rats and dispose of them (place in a tight plastic bag and leave with trash).
Trapping is good, but others will replace them. That is why the best way is to keep them out. Plug all holes in foundations and other access points. Use mortar, sand concrete, or pieces of galvanized steel. That hardwood floor on dirt is useless. Take it out and pour a concrete slab. Check all sewer lines; rats can come in through a broken main in the street, and can swim up the drain into the toilet.
Secure open vents or pipes on the roof or elsewhere with copper wire; make sure the cover is tight, rats can push a weaker top up and over.
The ideas are from a 1991 Fine Gardening Book called “Common Sense Pest Control’’ published by Taunton Press. Your library might have a copy. The book explains how to do things like set traps, plug openings, and other essentials to battle Rattus rattus, Rattus norvegicus, and the pesky mouse, Mus musculus.
Q. I live in a basement condo, and want to replace rugs with laminate flooring. I had a flooring company do a moisture test to test ground moisture. The reading was over their limit for moisture, and they won’t put down the laminate floor. They feel that it will buckle or pop up in a few years (even with a moisture barrier, pad, and 6 mil sheeting). Is there any way that I can still put down laminate? They suggested ceramic or vinyl. Are those my only choices?
DONNA HARRINGTON, BY EMAIL
A. Congratulations! You have found an installer who knows what he is doing and is honest. And I say, ceramic tile is the only thing that will work. It is expensive, especially in a place that you may not occupy for very long. It is waterproof and permanent, and you can put down wool area rugs.
Q. I painted a big piece of redwood outdoors, but it peeled off in two years, so I have to repaint. I know I have to sand it to the bare wood, but what kind of paint can I use so it will stick longer? Would the new primer-in-the paint work out?
A. Redwoods should take paint well, but it may not have been cured (dried) long enough. Wait six months before repainting. Use an exterior latex primer and a latex house paint. I frankly don’t think primer-in-the-paint will work very well until it is refined more. Stick with separate primer and house paint.
Q. The walls of a part of my house were rebuilt with plasterboard recently, along with joint compound and taped joints to repair damage. If I keep the house unheated all winter, will it damage the new plasterboard?
A. The joint compound on the new wall took only a few days, maybe a week to cure . Go ahead, there will be no damage from the lack of heat. It’s not the cold that messes up houses, it’s moisture.
Q. My toilet is filthy, and no matter what I do I can’t get that stain off. Toilet cleaner with bleach did nothing. I think it is mineral based, but none of the mineral busters did any good. Also, my tank is very black on the inside. What can I do ?
LINDA GRUBSTEIN, WAYLAND
A. Empty the bowl by shutting off the inlet valve, then flush the toilet. Rub the stain with a pumice stick or emery cloth. For mold in the tank, add a cup of bleach to the tank and leave it overnight. One cup of bleach in the tank occasionally will not hurt the septic system.