Choosing Underlay
Types of Underlay
Sponge Rubber - The market's most popular underlay is available in flat or waffle patterns in a wide range of weights for different applications. It performs well for comfort and has a durable spring retention.
PU (polyurethane) Foam -PU foam is a relative newcomer to the market, typically made from recycled foam offcuts. The foam provides excellent comfort and performance levels with lots of thickness options - and it is light weight helps handling, the product can be re-cycled again after use.
Crumb Rubber - Flat and dense, crumb rubber is good for heavy footfall - offering maximum protection but a little less comfort (and very good over stair nosings).
Laminate Underlay -There's still an opportunity to sell underlay with laminate flooring, improving the acoustic performance of the floor and helping the boards float above any imperfections in the sub-surface.
Combination - A rubber crumb base with a felt top layer offers a good combination of protection, durability and comfort. It also allows carpet with seaming to bed into the top felt.
Underfloor Heating Underlay - Always ask if there is underfloor heating. Most manufacturers offer specialised products. Underlay and carpet with a combined tog rating up to 2.5 can be used - which means the underlay would normally have a tog rating of 1.0.
Felt - This traditional (but environmentally friendly) underlay is made from recycled fibres - wool, jute and synthetic - to create a firm, dense pad with excellent thermal insulation. Still a very popular choice among contractors when stretch fitting woven carpets.
Benefits
Good underlay will ...
- Improve underfoot comfort
- Increase appearance retention, reducing flattening
- Absorb the pressure of foot traffic and reduce wear
- Improve thermal insulation and warmth
- Increase sound insulation
- Smooth out sub-floor imperfections
- Last the lifetime of the carpet
Poor or old underlay will ...
- Feel hard and unwelcoming
- Reduce carpet life
- Cause wrinkling and premature wear spots
- Cause carpet fibres to break down more quickly
- Not meet British Standards
How Thick?
A maximum of 12mm is recommended (working with gripper will be difficult thereafter) but rooms with heavy traffic will need a thinner, denser pad. The combination of thickness and density is all important as a thick underlay with low density may not perform well.
Typically the thicker the underlay, the better quality it will need to be - 11mm is often used for luxury installations with 9mm and 7mm the common domestic thickness.
