How to Close in a Basement Window
- 1). Cover the windows with masking tape to avoid glass shards should the window break during its removal.
- 2). Locate the nails holding any trim in place. Slide the pry bar between the trim and the wall next to the nails, then pull away the trim with the nails still in the trim body. Make your way around the window frame, pulling the trim away by each nail until you completely remove the trim.
- 3). Take a reciprocating saw and slide the blade between the window frame and the basement wall. Start the blade, then draw the blade around all of the frame sides to cut through any nails holding the frame in place. Turn off the saw and pull the frame, glass and all, from the wall, leaving behind a bare opening.
- 4). Clean off any paint from the bare opening using a wire brush, as paint can interfere with the mortar needed to brick up the opening.
- 5). Fill any cracks in the opening with epoxy resin. Push the resin into the cracks with a putty knife, then scrape the knife over the resin to level it. Wait one hour for the resin to harden enough to mortar over.
- 6). Gently brush the entire opening with epoxy bonding using a paintbrush.
- 7). Mix a masonry mortar mix in a wheelbarrow, using a spade to cut water into the dried mortar until it's of a peanut-butter-like consistency.
- 8). Spread a layer of mortar about 1/2-inch thick along the base of the opening with a trowel. Place the first row of concrete blocks into the opening on this layer of mortar. Choose blocks that come as close to the width of the opening as possible. Cut blocks as needed to fit the opening with a masonry saw. Butter the sides of each block with 1/2 inch of mortar before placing the blocks into the opening; begin the placement at one side of the opening, running the blocks closely butted together until you reach the other side of the opening. As you butt the blocks, mortar squeezes out from between them; scoop up the mortar with the trowel and discard the mortar. Check each row with a carpenter's level to make certain its level and plumb before continuing to the next level.
- 9). Place another layer of mortar on top of the first row of blocks, then run another row across the opening. Make sure the rows stagger along the joints. Create staggered joints by starting each run at the end of the previous run's row where a partial block is positioned.
- 10
Place frame ties into the wall after every two rows of blocks to add strength to the wall and to help the new blocks become a part of the existing structure. Hold the frame ties against the wall with the flat of the ties on top of the second row of blocks. Use a hammer drill with a masonry bit to drill a pilot hole through the tie mounting holes into the side of the window opening. Secure the ties with concrete fasteners. - 11
Apply a 1/2-inch layer of mortar over the ties and second brick row, then proceed with brick placement as normal. Place frame ties every other row. - 12
Continue until you've bricked up the entire window opening. Let the blocks sit in place for 24 hours to let the mortar dry. - 13
Spray the blocks with water until they are slightly damp. Apply a layer of plaster over the blocks with a trowel until the opening is even with the rest of the wall surface. Apply the plaster both inside and out to complete the closing in of the window.
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