Repairing Mortar in Brick Walls
QUESTION: The mortar joints on the brick walls of my house are dried and crumbling. How can I repair this?
ANSWER: The repair procedure for mortar joints on brick is known as “tuck pointing.” Start by chipping out all the loose mortar from the joints with a cold chisel and hammer to a depth of at least one inch. Clean away dust and chips with a water jet and wire brush. In areas where falling water is causing mortar leaks, remove the bricks and clean mortar from remaining bricks in the surrounding area.
Mix mortar from one part portland cement, one-half part hydrated lime, 4 1/2 parts sand and enough water so the mixture can be compacted into a ball. Let it stand for one hour, then add enough water to make a stiff but workable paste. Dampen joints with clean water. Use a jointing tool to force the mortar into joints. As you compress the mortar and strike off the joints with the jointing tool, work in one direction only to avoid forming air pockets.
Recommended Solvent to Remove Silicone
Q: The previous owner of my house used silicone caulk on everything in sight. How can I get it off?
A: The most common solvent for silicone caulk, as recommended by the Silicone Division of General Electric, is isopropyl alcohol. If that doesn’t do the job, you can try a stronger solvent such as paint thinner that contains Xylene.
Clothes Get Mildewed in Basement Closet
Q: About a year ago, I built a closet in the basement to store our clothes in the off-season. Our summer clothes were stored last winter and they were fine this spring when I took them out. However, when I retrieved our winter clothes which had been stored for the summer, I found them full of mold and mildew. How can I solve this problem?
A: Basements, because they are below grade, are cooler in the summer than the rest of the house. As a result, the moisture in the humid summer air tends to condense in the basement, making that area quite damp. This, in turn, promotes the growth of mold and mildew.
Opening the windows and using a fan to circulate the air will only work when the humidity of the outside air is not as high as it usually is in the summer. And the problem is compounded in a closet because of the confined space and stagnant air.
The best approach is to install a dehumidifier in the basement. While it’s not practical to place it in the closet, you can install vent openings in the top and bottom of the closet door to help circulate the basement air.
Another approach is to use chemicals that absorb moisture such as silica gel and activated alumina. These have the capacity to absorb half their weight in water. They can be placed in the closet in a bucket or in cloth bags hung from the closet pole. After they’ve become saturated, the water can be drawn off by heating and the chemicals can be reused.
Repairing Wood Rot Caused by Rain Runoff
Q: I have an old house with a small detached garage. Rain runoff flows down my driveway and through the garage, and the soleplate has been repeatedly soaked. Both the soleplate and the bottoms of the wall studs have started to rot. The rest of the building is in good shape, and I would like to save it for a workshop. Is there a way to repair this building that’s economically feasible?
A: Before repairing the garage, you should eliminate the water penetration. Install a drain across the driveway in front of the garage to catch and deflect the runoff. Cut a small channel, about eight inches wide across the driveway, fill with gravel and cover it with a grate. Provide a free-flowing outlet using 3- or 4-inch diameter pipe to direct water downhill and away from the garage.
If the driveway is not steep, you might simply divert the water with an asphalt lip across the driveway, 2- to 3-inches high. Diverted water should flow to a lower area in the lawn.
Before cutting away the rotted portions of the wall, you must erect supporting braces. Working on one wall at a time, nail a 2-by-4 under every other ceiling beam. This will relieve the pressure on the wall and allow the rotted framing to be cut away without collapsing the building.
Remove the rotted sill and cut off the bottom of the studs and sheathing 11 1/8-inches above the floor. Set a row of 8-inch concrete blocks (that usually measure about 7 1/8-inch high in a bed of mortar so they align with the outside of the garage wall.
Mortar anchor bolts into the block cavities so they protrude 1 1/2 inches above the top of the blocks. Use three anchor bolts per wall. Bore matching bolt holes into a new 2-by-6 sill, then slide the sill in place and tighten the anchor bolt nuts. Then, nail a 2-by-4 along the length of the 2-by-6, laying it flat to form a sole plate. Finally, toe nail the studs to the 2-by-4 with galvanized 8-penny nails. Trim the siding flush with the tops of the blocks to finish off the job.