Don’t make the mistake of believing that you will save money by utilising your old underlay. It will probably have little, if any, life left in it, and certainly next to no bounce or resilience.
Good underlay will...
- Improve underfoot comfort
- Reduce flattening and improve appearance retention
- Absorb the pressure of foot traffic and reduce wear
- Improve thermal insulation and warmth
- Increase sound insulation
- Smooth out minor 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 breakdown more quickly
- Not meet British standards
How Thick?
A maximum of 12mm is recommended as working with gripper rod becomes difficult if any thicker, but rooms with heavy traffic will need a thinner denser underlay. The combination of thickness and density is all important as a thick underlay with a low density may not perform well. Typically the thicker the underlay the better quality it will need to be - 9- 7mm is the most common domestic thickness with 11mm often used for luxury installations.
Types of Underlay
Sponge Rubber
The most popular underlay on the market, 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
The foam provides excellent comfort and performance levels with lots of thickness options - and its light weight helps handling. The product can be recycled again after use.
Crumb Rubber
Flat and dense, crumb rubber underlay is good for heavy footfall - offering maximum protection but a little less comfort. Crumb rubber is very good for stair nosings.
Combination
A rubber crumb base with a felt top layer offers a good combination of protection, durability and comfort. It also allows carpet seaming to bed into the felt top.
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 popular choice among contractors when stretch fitting woven carpets.
Pre - tackified Underlay
A self - adhesive single stick underlay in both needlefelt and PU. A removable system for heavy use when comfort is desired.