Nail laminated timber NLT
Nail laminated timber (NLT or also called nail-lam) uses standard dimension timbers (normally 2" x 4", 6", 8" or 10"). The individual members are laid on edge and nailed to the next timbers with a relatively high number of long, strong galvanised nails, which gives strength and weight enough to qualify as a massive wood panel product. In German it may be referred to as nail brettstaple, which is translated literally as a nailed board stack but more commonly is associated with dowel laminated timber (DLT) rather than nails.
In the US NLT qualifies as a heavy timber product as a result of the number and length of nails and is used for roofs and where slightly deeper, for floors as well as for vertical wall elements. Where used vertically as shear walls or diaphragms it may have plywood or OSB added to one face to provide improved shear capacity. In the horizontal NLT panel depths of about 100mm can span in a single direction up to around 3.5 metres, increasing to about 8 metres if depths increase 3 fold. Due to their massive wood heavy weight nature they can be used as an alternative to concrete slabs or steel decks in commercial and institutional buildings, as well as residential buildings. Fire rating is likely to be similar to cross laminated timber (CLT) products (normally designed to FR 30,60 or 90 minutes), though in the case of NLT the metal connections should also be protected, for example through the use of sacrificial timbers for charring rate or gypsum board cover. The types and quality of timbers used will also impact fare rating, so in each case specific product designs should be checked against relevant standards, such as ISO 834, EN 1995-1-2, EN 1991-1-2 and in the US chapter 16 of NDS and AWC TR 10.
The main advantages of the product are that it can use relatively low grade sawn timbers from a variety of species, which are readily available in standard dimensions and does not require complex machinery to create panels, which can even be made on site. Although it is classified as a heavy timber product it is in comparison, relatively lightweight and easier to handle than concrete and steel alternatives. It has an aesthetic appeal, with environmental sequestration credentials and because it uses no glue has some consideration to end of life, though not as significant as dowel laminated timber due to the mixing of metal and wood components not easily separated under and end-of-use scenario.
[edit] Related articles on Designing Buildings
- Carpentry.
- Compressive strength of timber lattice columns for low-rise construction.
- Cross laminated timber.
- Dowel Laminated timber.
- Engineered bamboo.
- Engineered wood products.
- Facts about forestry.
- Glulam.
- Janka hardness rating scale.
- Laminated veneer lumber LVL.
- Modified wood.
- Nails - a brief history.
- Plywood.
- Predicting service life of timber structures.
- Sustainable timber.
- Testing timber.
- The differences between hardwood and softwood.
- The use of timber in construction.
- Timber frame.
- Timber vs wood.
- Types of timber.
- Types of timber species.
- Whole life carbon assessment of timber.
- Wood around the world.
Featured articles and news
About the 5 Percent Club and its members
The 5% Club; a dynamic movement of employers committed to building and developing the workforce.
New Homes in New Ways at the Building Centre
Accelerating the supply of new homes with MMC.
Quality Planning for Micro and Small to Medium Sized Enterprises
A CIOB Academy Technical Information sheet.
A briefing on fall protection systems for designers
A legal requirement and an ethical must.
CIOB Ireland launches manifesto for 2024 General Election
A vision for a sustainable, high-quality built environment that benefits all members of society.
Local leaders gain new powers to support local high streets
High Street Rental Auctions to be introduced from December.
Infrastructure sector posts second gain for October
With a boost for housebuilder and commercial developer contract awards.
Sustainable construction design teams survey
Shaping the Future of Sustainable Design: Your Voice Matters.
COP29; impacts of construction and updates
Amid criticism, open letters and calls for reform.
The properties of conservation rooflights
Things to consider when choosing the right product.
Adapting to meet changing needs.
London Build: A festival of construction
Co-located with the London Build Fire & Security Expo.
Tasked with locating groups of 10,000 homes with opportunity.
Delivering radical reform in the UK energy market
What are the benefits, barriers and underlying principles.
Information Management Initiative IMI
Building sector-transforming capabilities in emerging technologies.
Recent study of UK households reveals chilling home truths
Poor insulation, EPC knowledge and lack of understanding as to what retrofit might offer.