Underlay
Underlay or underlayment is a term used to describe materials in both flooring and roofing.
[edit] Flooring
Underlay in flooring is material typically made from rubber, sponge, foam, felt, plastic and so on. It serves as a protective layer between the 'unfinished' subfloor and the final floor covering. Depending on the material selected, underlay can help provide thermal and acoustic insulation, reduce impact noise, reduce wear and enhance comfort. It is sometimes advisable to use higher quality underlay in order to avoid the deterioration that can occur with lower quality products that can harden and crumble over time.
Underlay is most commonly used under vinyl flooring, wood flooring and carpet. Some forms of carpet - such as rubber or foam backed carpet - do not require underlay.
[edit] Roofing
Underlay in roofing is material made from rubber, felt, tar paper, synthetic underlayment and other protective substances. As a roofing membrane, the purpose of underlay is to helps to prevent water that has penetrated through or under the roof covering from leaking into the building.
There are non-breathable underlays and breathable underlays based on ventilation requirements of the roof.
NB The 2018 International Residential Code (IRC), published by the International Code Council (ICC) defines underlayment as: ‘One or more layers of felt, sheathing paper, nonbituminous saturated felt, or other approved material over which a roof covering, with a slope of 2 to 12 (17-percent slope) or greater, is applied.’
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
ECA Industry Awards 2024 shortlist revealed
22 leading businesses from across the electrotechnical and engineering services sector.
Government unveils Skills England strategy
Skills England to transform opportunities and drive growth.
New Government Hub for York Given Planning Green Light
For up to 2,600 civil servants, due for completion by 2028.
Construction Skills Certification Scheme cards
July update on Professionally Qualified and Academically Qualified Person Cards.
BSRIA Briefing 2024, November 22
Sustainable Futures: Redefining Retrofit for Net Zero Living.
The CLC on driving competency in the retrofit sector
Previously published roadmap on skills for net zero.
The first labour government King's speech in fifteen years
Construction industry reactions, support and some concern.
CIOB Retrofit of Buildings Technical Information Sheet
What retrofit is, the approach to be taken and processes to be followed.
Adapting Historic Buildings for Energy and Carbon Efficiency
Historic England advice note 18, free download published.
10 retrofit projects revisited 10 years after completion.
Information orders, building liability orders and SPVs
Key BSA terms and how they impact special purpose vehicles.
Listed despite problems with its design.
Zen and the art of cycling exploration.
Design Council Homes Taskforce launched
To support government 1.5 million homes target within UK climate commitments.