How to Seal up a Doorway in a Block Wall Part 2 How to Seal up a Doorway in a Block Wall Part 2

When sealing a doorway in a block wall, the installation can be broken down into several steps. The final steps before hanging the drywall will take you from installation of the first row of blocks through being ready to hang the drywall. (This is Part 2 of a 2 part series. To return to Part 1, click here.)

Install First Row of Blocks and Mortar

You will need to begin by preparing your pre-mixed mortar. It is best to use cool water to add to the mixture and blend together until you have the consistency of frosting. The mixture should spread easily and not be too thick or too thin. You can verify that you have the correct consistency by applying a small amount of the mortar to the side of a glass block to see if the mortar will stick.

When installing the first row of blocks you will need to apply the mortar mixture directly to the sill that is already in place using a trowel. Completely cover the sill and create a bed of mortar for the first row of blocks to rest in. Place one block at a time into the mortar and verify that it is aligned straightly and level by placing a level on top of the block and against the side of the block. Once the block is straight, continue in a line with the seceding blocks checking the levelness as you proceed. Add spacers between each block to ensure their position relative to one another. Now you will need to add mortar between each of the blocks. You need the space between each set of blocks to be filled enough to ensure the blocks will be stable. If any mortar oozes or seeps out just wipe with a wet sponge before it can dry.

Installing Additional Rows of Blocks

Once the first row of blocks is set you can move on to increase the height with additional rows. Apply mortar to the top of the blocks in the first row. Place the second row of blocks into the bed of mortar using a moist sponge to wipe and extra mortar as you go. As with the first row, place the blocks down the row and then go back and add the spacers and mortar between each block. Continue to verify the arrangement of the blocks by using a level on the top and sides of each block.


Once your blocks are in place you should let them set for at least 1 hour. It is best to use the wet sponge as you work to remove as much excess mortar as possible. After the hour of drying time, if there is any mortar that needs removing, you can use the striking tool. As well, use the striking to smooth and corners, rough spots or joints. You will need to use silicone caulk along the outside blocks to seal the sides and corners. You can also add a sealer to the blocks to prevent mildew.

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