Laying underlay is a crucial step in preparing your floor for new coverings, providing benefits like insulation, soundproofing, and enhancing the longevity of your chosen flooring. The process involves careful preparation, correct orientation, and precise cutting to ensure a smooth, durable foundation.
Understanding Underlay Orientation
The most critical rule when laying underlay, as a rule of thumb, is ensuring the correct side faces up: any branding or backing should be facing up into the room, with the rubber or foam side facing down towards the subfloor. This orientation is vital for the underlay to perform optimally, offering its intended benefits, whether it's cushioning, thermal insulation, or sound dampening.
Essential Tools
Before you begin, gather the necessary tools to ensure a smooth installation process:
- Measuring Tape: For accurate measurements of the room and underlay strips.
- Utility Knife/Craft Knife: A sharp blade is essential for clean, straight cuts.
- Straight Edge/Ruler: To guide your knife for precise cuts.
- Work Gloves: To protect your hands during cutting and handling.
- Underlay Tape (optional but recommended): For sealing seams between underlay strips, preventing movement and enhancing moisture protection.
- Vacuum Cleaner: For thoroughly cleaning the subfloor.
Step-by-Step Guide to Laying Underlay
Follow these steps to lay your underlay correctly and efficiently:
1. Subfloor Preparation
A clean, level, and dry subfloor is fundamental for a successful underlay installation.
- Clear the Area: Remove all furniture, existing flooring, and old underlay.
- Clean Thoroughly: Vacuum the entire subfloor to remove dust, debris, and any small particles.
- Inspect and Repair: Check the subfloor for any damage, unevenness, or protrusions. Fill cracks, sand down high spots, or use a self-levelling compound if necessary. Any imperfections can affect the final flooring.
2. Planning Your Layout
Consider the shape of the room and the direction you want your flooring to run. Generally, it's best to start laying underlay from one corner of the room and work your way across.
3. Laying the First Strip
- Unroll: Begin by unrolling the first strip of underlay against one wall, ideally the longest wall.
- Orientation Check: Double-check that any branding or backing is facing up into the room, with the rubber or foam side facing down towards the subfloor. This is crucial for proper performance.
- Placement: Ensure the underlay sits snugly against the wall or carpet gripper if present.
4. Cutting to Size
- Measure and Mark: Once you've reached the end of the room, unroll the underlay past the wall or gripper.
- Precision Cutting: As per the rule of thumb, "chop off the roll so that the underlay very slightly overlaps the gripper at both ends." Use your utility knife and a straight edge to make a clean, straight cut. This slight overlap ensures full coverage and stability.
5. Laying Subsequent Strips
- Butt Edges: Unroll the next strip of underlay, butting its edge tightly against the previous strip. Avoid overlapping the underlay strips themselves, as this will create unevenness.
- Secure Seams (Optional but Recommended): For enhanced stability and moisture protection, use underlay tape to seal the seams between adjacent strips. This prevents movement and maintains the integrity of the underlay layer.
- Continue: Repeat the process of unrolling, positioning, and cutting until the entire floor area is covered.
6. Navigating Obstacles
- Doorways: Cut the underlay to fit precisely around door frames, ensuring it extends under the threshold where the flooring will meet.
- Pipes/Irregular Shapes: Create a template using paper if the shape is complex, then transfer the template to the underlay for precise cutting.
Key Considerations
- No Gaps: Ensure there are no gaps between the underlay strips. Even small gaps can compromise the performance of the underlay and the final flooring.
- No Overlaps (of underlay strips): While the underlay should slightly overlap the gripper, individual strips of underlay should not overlap each other, as this creates uneven ridges.
- Acclimatization: If recommended by the manufacturer, allow the underlay to acclimatize to the room's temperature and humidity for 24-48 hours before installation.
By following these guidelines, you can effectively lay underlay, creating a solid and supportive base for your new flooring.
