Sealing Rodent Gaps in an Old Akron Basement

If your Akron house was built before the Second World War, the basement is probably where the mice get in. Homes from the rubber-boom years sit on sandstone, fieldstone, brick or early concrete block, and a century of freeze and thaw has opened gaps that weren't there when the house was new.

This guide walks through the usual entry points in an old basement, from the top of the wall to the floor drain, and what to use to close them. It's written for older homes in neighborhoods like Kenmore, Firestone Park and North Hill, but most of it applies anywhere.

Start at the top of the wall

The sill line is where the wood framing of the house sits on top of the foundation. In old houses, it's rarely tight. The sill may have shifted, the mortar under it may have crumbled, and in a block foundation the top course of block often has open cores that run along the wall. A mouse that gets into those hollow blocks can travel the whole length of the house.

Use a flashlight and look along the top of the wall all the way around. You may need to move boxes or pull back insulation stuffed between the joists. Look for gaps, droppings, gnaw marks and dark rub marks on the wood. Old insulation stuffed into the rim area often hides gaps and also makes a great nest.

The coal chute, the windows and the pipes

Many old Akron houses had coal furnaces, and the coal chute is often still there, covered over with a board or a piece of plywood. Check it. Old basement windows with rotted wood frames are another common gap, especially when the window well fills with leaves. Then follow every pipe and wire that comes through the wall: gas, water, sewer, electric, cable, the old oil fill pipe if there is one. Each one was a hole somebody drilled, and few were ever sealed tight.

• Coal chute doors and boarded-over openings
• Window frames, especially wood frames that have rotted
• Gaps around the gas line, water main and electric service
• Abandoned pipes and old oil fill lines
• Cracks in the floor and around the floor drain
• Gaps where a later addition or porch meets the old foundation

Stone and block need different fixes

For stone foundations with mortar gaps, pack copper or stainless mesh into the gaps and cover with mortar or a masonry sealant. For lots of open joints, a mason may need to repoint the wall, which is a bigger job. For block walls with open cores, the top course can be filled or capped. Hardware cloth or sheet metal works for bigger openings like coal chutes and old vent holes. Rotted window frames should be repaired or replaced.

Floor drains and old sewer connections deserve their own mention. Rats can travel through broken sewer lines, and a floor drain without a proper cover is an open door. If you suspect rats are coming up through a drain, call a plumber as well as a pest tech. Summit County Public Health notes that sewer rats are a problem where sanitary sewers are in disrepair.

When to bring in help

Some of this is weekend work. Some isn't. If the gaps are high up, hidden behind finished walls, or there are just too many of them, a rodent exclusion visit is the better route. If mice are already inside, the tech will start with basement rodent control and trap before sealing so nothing ends up stuck in the walls. Old houses in Kenmore's boom-era blocks, North Hill and Barberton tend to need the most sealing. If rats are in the picture, the rat control page covers the outside work.

Whatever you do, avoid loose poison in the basement. If bait is used, it should be in locked stations. And when you clean up droppings, wet them first with disinfectant. Never sweep them dry.

See also: Rodent Exclusion and Sealing, Basement and Crawl Space Rodents, Rat Control