underlay fitting guide

A Guide to Fitting Underlay


Carpet Underlay


Carpet underlay makes your carpet feel even softer and more luxurious. Underlay absorbs any wear and tear so it doesn’t show on the surface, giving it longevity and maintaining its appearance for a longer time.


Laminate Underlay


Laminate underlay serves to add extra comfort to your laminate flooring as well as reducing the flexing that can occur without it when it’s walked on. It also helps to reduce footstep noise on the hard surface, and traps in heat to make your home warmer as it’s a great insulator.


Wood Flooring Underlay


Just like underlay for laminate, wood flooring underlay can keep your engineered wood flooring looking stunning for longer and reduce your energy bills by trapping in heat. It doesn’t just keep your home warm, it also cuts down on noise from footsteps and protects your flooring from the damage caused by moisture.


Underfloor Heating


If you have underfloor heating, you will need to use a specific underfloor heating underlay with it. These specialist products allow air to circulate and their low tog rating lets heat penetrate through the floor.


Preparing the Floor for Carpet Underlay


Firstly, before anything is fitted, ensure the floor is clean and free from nails or staples that could be present if it has previously been carpeted. Give the floor and sweep or vacuum to get rid of any dust and grit or anything lying on the surface that could cause bumps.


Tools required to fit carpet underlay


  • Utility knife
  • Underlay tape
  • Staple gun
  • Hammer
  • Spray adhesive

Fitting underlay for carpet


It’s important to use a high quality underlay as this will give your carpet a much longer life. It’s a good idea to also use floor lining paper as this stops the underlay from sticking and protects your carpet from dirt and dust.

  • Roll out the lining paper if you are using it and fix with a hammer tacker or heavy staple gun. Fix around the edges by spraying with adhesive ensuring the rows overlap slightly.
  • Take the underlay and lay it loosely rubber side down. Use the knife to trim it so it is level with the gripper rods.
  • Butt rows of underlay together but do not overlap them. Use carpet tape to join them.
  • If you have doorways and recesses, cut the underlay into and around these spaces. It’s OK but not ideal, to add an extra piece of you need to but make sure it remains flat.
  • Ensuring you keep the underlay straight and gap-free, staple it along its edges inside the gripper. Use adhesive if you are laying carpet onto a concrete floor.
  • Use tape to stick along the full length of joins. Use the knife to trim off any excess underlay inside the grippers.

Fitting underlay for laminate flooring


There are various types of underlay for laminate flooring each with different advantages. Thicker options offer more sound proofing, which could be a consideration if you are laying a floor in an upstairs room or flat.

  • Bear in mind that not all underlay types are suitable for wet areas such as kitchens and bathrooms while some types come with a built-in damp-proof membrane.
  • Lay the underlay over the entire floor and trim to fit, cutting a 16mm gap around any pipes.
  • Lay lengths parallel and stick together along the length of the joins with masking tape.

Fitting underlay for engineered wood flooring


Again, bear in mind that not all underlays are suitable for wet areas such as kitchens and bathrooms but there are some types that come with a built-in damp-proof membrane.

  • Place the underlay at one end of the room and unroll from the wall.
  • Lay lengths parallel using scissors or a knife to trim and stick together with masking tape.
  • Continue in this way across the room. Although we need the edges to meet, it’s important to ensure they don't overlap as this will create an uneven floor.
  • Leave a gap of 10mm around pipes.