How to Seal up a Doorway in a Block Wall Part 1

  • 4-12 hours
  • Beginner
  • 100-500
What You'll Need
Pre-mixed mortar
Glass or clay blocks

When you need to put up a block wall to seal up a doorway, this easy step-by-step guide is the guide for you. Before you begin working on this project, you must do some preparatory activities. First, identify the doorway that you want to seal up. Second, measure the height of the doorway and the width of the area that needs sealing up. Third, collect your materials and equipment. Lastly, begin your work process. (This is Part 1 of a 2 part series. To move ahead to Part 2, click here.)

Step 1 - Prepare the Mortar and Blocks

Get the pre-mixed mortar and blend it well with water to get a smooth frosting-like consistency. This mixture must be able to spread nicely and evenly. Check the consistency by taking a small amount and spread it on the side of the glass block (if preferred to use). Determine if the mortar sticks well onto it.

Step 2 - Install the Initial Row

Put some mortar mixture with your trowel on the sill at the bottom prior to putting the first layer of blocks. Make sure that you have completely covered the sill with mortar as the bed of the initial block row. Put in one block at a time. Check the alignment of the blocks every now and then. You may also use a ruler or a t-square to check the alignment of the blocks. Once you have determined that they are straight, begin working on the second row.

Continue checking the alignment after every row of blocks. Be sure to place mortar first on the bottom to ensure that the blocks get to stick securely with each other as you form the block for the door. Add spacers between blocks to secure their position with one another. Fill the space with mortar to allow the blocks to stick with each other and make the block more stable. If there is seeping out of mortar, wipe it with a wet sponge before it is completely dry.

Step 3 - Install Additional Rows

After the first row of blocks have set and dried, move on by adding the next rows of blocks. Prior to applying the next row of blocks, apply the mortar first on the top of the first row. Then, slowly add the blocks on the second row of the mortar bed using a moist sponge to wipe away extra mortars on the sides or bottom. Put some mortar on the spacers and continue checking arrangement and alignment of blocks.

Step 4 - Finishing Touches

Let the mortar and the blocks set in for at least an hour. Continue wiping excess mortar with your sponge until the block wall has dried up and becomes sturdy. If there is a certain part of the area where the mortar was not properly placed, or is oozing out, remove the dried mortar with a striking tool. Add silicone caulk on the outside portion of the block to seal both sides and corners. Finally, add a sealer to the blocks if you want to prevent mildew from growing inside.