Underlay - Your Carpet's Most Supportive Friend

When buying and fitting a new carpet you should always choose a good quality underlay that will not only extend the longevity of the carpet but will also improve its appearance and aid with insulation and acoustic dampening. Laying a new carpet over an existing or old underlay (4-5 years old) should be avoided as it will not provide the necessary level of support underneath or offer the required amount of resilience and bounce underfoot especially in high traffic areas such as hallways and stairs.

Advantages of new underlay:

• Comfort underfoot

• Improve longevity of carpet reducing matting and flattening

• Increase thermal insulation

• Smooth out small subfloor imperfections

Disadvantages of old underlay

• Reduce carpet life span

• Cause premature flattening

• Not meet British standards

• Cause carpet fibres to matt and break down quicker

Underlay Thickness

Underlays are available in a range of different thicknesses, and these should be taken into consideration when choosing the right one for your floor. As a rule, a thicker underlay will give your carpet a more luxurious feel and aid with acoustics and heat insulation. We recommend choosing an underlay with a thickness between 6mm to 9mm and with a good density to aid with the overall support of the carpet and furniture sitting on top. Also be mindful of the thickness of the carpet as well as the underlay so that doors will open and close freely and to avoid having to get doors cut and rehung because the flooring is too thick. With thicker underlay (10mm+) a thicker gripper will need to be used to ensure correct fitting.

Types of Underlay

The following is a list of the main types of underlay available offering different properties depending on room use, type of carpet and how the room is heated;

PU (Polyurethane) Foam - Made from recycled foam off cuts, this is the most popular underlay which comes in a range of thicknesses and provides excellent comfort and support

Sponge rubber - A traditional underlay made in a wide range of densities for different applications. Excellent underlay for durable spring retention and comfort.

Crumb rubber- This is a dense underlay that is ideal for areas with heavy footfall, offering great protection but less comfort underfoot – ideally suited for over a stair nosing.

Felt – Another traditional underlay made from recycled materials such as wool, jute and synthetic fibres which offers great thermal insulation and is also environmentally friendly.

Combination – A rubber crumb base with a felt top layer offers a good combination of protection, durability and comfort. Good for carpet joins as it allows carpet with seaming tape to embed into the top felt.

Underfloor heating underlay – A low Tog rating to allow heat to conduct through. 2.5 is the maximum Tog for carpet and underlay which means the underlay in this instance could be as low as 1.0.

For further advice and tips on underlay please drop by our Flooring Store in Spring Lane where our experts are on hand to give you all the help and guidance you need.