How to Lay a Floating Subfloor over Concrete Part 2 How to Lay a Floating Subfloor over Concrete Part 2
Now that you have prepared the cement floor and the subflooring for installation, you are ready to plan your installation layout and begin the install. (This is Part 2 of a 2 part series. To return to Part 1, click here.)
Step 3 - Planning the Installation
The best project is a well planned project and planning is easy to accomplish in this case. Begin by laying out your first row of subfloor starting in the farthest corner of the room. You want to place the first piece of flooring with 2 sides flush against a wall and backed into the corner. Lay the subsequent flooring sections in this row all the way to the opposite wall to complete the entire first row. If required, cut the last piece of subfloor in this row to fit. Now you are ready to chalk your outline onto the floor. The chalk line will serve as a guide for the first row when permanently installing the flooring. After chalking the first row, you can pick up all but the first piece. As well, you should check to see if the corner is a true 90 degree square corner. Not all corners are exactly 90 degree angles and you may need to make alterations to your flooring pieces to accommodate the corners of the room. If you need to alter a piece of subfloor to fit into a corner, simply measure the corner and then make the appropriate alterations to the flooring. Remember throughout the installation, if you are working with a cut piece of flooring to place the cut side inward.
Now you are ready to begin installing the subfloor.
Step 4 - Installation
Place the first piece of subflooring into the farthest corner of the floor with 2 sides flush to the surrounding walls. Now take your second piece of subflooring and align it next to the first. With a wood block and hammer, gently connect the second piece to the first by tapping it into place. You will have connected the tongue and grove joints of the two pieces creating a bond. You want the pieces to fit together securely so the seams do not separate or loosen over time. After laying every other piece, you should check the levelness of the subflooring to ensure you remain in alignment. If you find that your row is not level, simply use shims to create the alignment you need. Now repeat these steps with the remaining pieces in the first row.
Once the first row is in place, you will need to cut the first piece of subflooring for the second row. You should cut the first piece of the second row so that it aligns with the middle of the first piece of the first row. This will allow for the flooring pieces in the second row to be staggered from the flooring pieces of the first row. After cutting the first piece of the second row, install the second row just as you did the first row. When the second row is complete, each one of the joints in the second row should align with the middle of a piece in the first row to create a staggered or offset look.
Now you are ready to place the third row. You will not need to make a cut to the first piece of the third row. The first piece in the third row should align exactly with the first piece in the first row. Lay the first complete piece in the third row and then complete the third row just as with the first row. Once the third row is complete, the seams of the third row should match the seams of the first row.
As you continue the installation, you can follow these same steps. As you proceed, the first piece of the fourth row would need cutting to match the first piece of the second row. Every odd numbered row would require you to cut the first piece, and every even numbered row would require you to cut the first piece.
Continue laying rows of the subfloor from the farthest side of the room to the other. As you work, use a level and be aware of the fit between the pieces and rows. You may need to level the cement flooring or add shims under a piece to create the correct height and alignment.