Cross Laminated Timber (CLT)

cross
laminated
timber.

Cross-laminated timber (KLH®, BSP, CLT, X-LAM, Cross-Lam) is made from spruce slats stacked atop of each other which are bonded using high press force and formaldehyde free adhesives to form large-format building elements.

modern facilities.

In our modern production facilities, the elements are exclusively produced in a project-related way. The thickness of the elements and the number of plies used mostly depends on the structural and fire-protection requirements. On the basis of approved production plans, the elements are cut using state-of-the-art CNC systems. The elements are delivered directly to the construction site on a just-in-time basis, either by lorry or in a container. On location, they are mounted by the expert personnel of a timber construction company or that of a construction company using a construction crane.

Product Advantages

• Ecologically sustainable construction material
• Healthy, comfortable room climate
• Stable value with elements manageable in terms of building physics
• Highest-possible freedom in architectural implementation
• Simple planning of individual structures
• Optimal utilisation of the enclosed plot area by using slim construction elements

• Statically highly stable, large-format and thus assembly-friendly elements
• Short construction period, dry construction method and quick readiness for occupancy
• Quality-controlled production internally as well as externally
• High dimensional accuracy with CNC-controlled cut
• Technically approved and CE-marked construction product
• Delivery of the elements pre-manufactured under weather-protected conditions directly to the construction site

Solid
wood
panels.

KLH® SOLID WOOD PANELS ARE IDEALLY SUITED FOR LOAD-BEARING, BRACING AND NON-LOAD-BEARING WALL, CEILING AND ROOF ELEMENTS.

Manufacture

The crossways arrangement of the longitudinal and crosswise laminates reduces the swelling and shrinkage in the board plane to an insignificant minimum and static strength and shape retention increase considerably. According to the European Technical Assessment exclusively technically seasoned timber with a wood moisture content of 12% (+/-2%) is used. Any timber laminates are subjected to quality control before their use.

Adhesives &
lamination process

Only VOC-free and formaldehyde-free PUR adhesives are used in accordance with EN 15425. The adhesives have been tested and classified as TYPE 1 adhesives and have been approved for the production of load-bearing timber components.

The adhesive is applied automatically over the entire surface approx. 0.15 kg/m² per joint. The laminated pressure at 0.6 N/mm² used during the manufacture of KLH® solid timber panels is 6 times higher when compared with vacuum press technology. The quality of the lamination of KLH® CLT is therefore of high quality and the load-bearing capacity comparatively higher.

CNC – Cutting

Factory cutting or beaming takes place using state-of-the-art CNC-technology. The basis for that form the production and cutting plans released by the client or the executing company, respectively. For elements of a length and width > 1 m the tolerances are +/-2mm, for standard panel types, standard trimming and a wood moisture content of 12%.

We furthermore produce and deliver unmachined raw panels to supply CNC trimming service factories and processing mills, from where the elements are then transported to the site.
For further information please contact us.

Assembly &
Installation

The cut-to-size KLH® solid cross-laminated timber elements are delivered to the construction site just in time, and there they are assembled by expert timber construction companies or construction companies using a building crane within the shortest possible construction period. The connection of tradition, well-founded craftsmanship and state-of-the-art timber construction technology enables individual, stable-value constructing with particular attention being attached to the environment and energy consumption.

We are offering various lifting systems, depending on the panel type, panel size and surface quality. All lifting systems installed in our factory are CE-marked.

Technical Approvals, Certificates and Eco-labels

Panel types

KLH® solid timber panels are offered in 3 standard qualities. Upon request special surfaces and panel built-ups are possible, depending on the availability of the raw lamellas and technical feasibility. Special structures are possible upon request.

Technical characteristics

Product name / Brand	KLH®
OTHER PRODUCT NAMES	Cross-laminated timber (CLT) | X-Lam
APPLICATION	Structural elements for walls, floors and roofs
DURABILITY	Service classes 1 and 2 according to EN 1995-1-1
WOOD SPECIES	Spruce (pine, fir, stone pine and other wood types on request)
PANEL BUILD UP	3, 5, 7 or more layers depending on static requirements
LAMELLAE	Thickness 20 to 45 mm, technically dried, quality-sorted and finger-jointed
STRENGTH CLASS	C 24 according to EN 338, maximum 10% C 16 permitted (compare ETA-06/0138)
ADHESIVE	Formaldehyde-free PUR adhesive, approved for load-bearing and non-load-bearing components indoors and outdoors according to EN 15425
LAMINATING PRESSURE	At least 0.6 N/mm²
WOOD MOISTURE CONTENT	12% (+/- 2%) on delivery
MAXIMUM ELEMENT DIMENSIONS	Length 16.50 m / width 2.95 m / thickness 0.50 m
PRODUCED WIDTHS	2.40 / 2.50 / 2.73 / 2.95 m
SURFACE QUALITY	Non-visual quality (NVQ) | Industrial visual quality (IVQ) | Domestic visual quality (DVQ) Special surfaces on request
WEIGHT	5.5 kN/m³ according to ÖNORM B 1991-1-1:2011 for structural analysis 500 kg/m³ for determination of transport weight
MOISTURE MOVEMENT	In panel plane 0.01% per % change in wood moisture content, perpendicular to panel plane (panel thickness direction) 0.24% per % change in wood moisture content
THERMAL CONDUCTIVITY	λ = 0.12 W/(m*K) according to EN ISO 10456
HEAT STORAGE CAPACITY	cp = 1600 J/(kg*K) according to EN ISO 10456
VAPOUR RESISTANCE	µ = 20 to 50 according to EN ISO 10456
AIR TIGHTNESS	KLH® solid wood panels can generally be used as airtight layers. Connections to other components, butt joints, penetrations, etc. must be sealed appropriately.
REACTION TO FIRE	Euro class D-s2, d0
RESISTANCE TO FIRE	According to ETA – 06/0138

 

By using double layers, the board’s longitudinal and transverse rigidity can be increased in a targeted manner. Changes to the board structure can be used to increase its fire resistance in order to meet special project requirements.

Maximum format	Length 16.50 m / Width 2.95 m / Thickness up to 0.50 m
Minimum production length	8.25 m – respectively in 5 cm increments up to the maximum length
Calculation widths	2.40, 2.50, 2.73, 2.95 m

Panel types
Overview

 

For the wall Covering layer in the transverse panel direction TT

Nominal thickness in mm		in Layers	Typ	Lamella structure [mm]
				C	L	C	L	C	L	C
KLH®	60mm	3s	TT	20	20	20
KLH®	70mm	3s	TT	20	30	20
KLH®	80mm	3s	TT	30	20	30
KLH®	90mm	3s	TT	30	30	30
KLH®	100mm	3s	TT	30	40	30
KLH®	110mm	3s	TT	40	30	40
KLH®	120mm	3s	TT	40	40	40
KLH®	100mm	5s	TT	20	20	20	20	20
KLH®	110mm	5s	TT	20	20	30	20	20
KLH®	120mm	5s	TT	30	20	20	20	30
KLH®	130mm	5s	TT	30	20	30	20	30
KLH®	140mm	5s	TT	30	20	40	20	30
KLH®	150mm	5s	TT	30	30	30	30	30
KLH®	160mm	5s	TT	40	20	40	20	40

For slab and roof Covering layer in the longitudinal panel direction TL

Crosslam timber / CLT- Fire resistance and rating

One of the major advantages of Cross Laminated Timber is its inherent fire resistance. CLT can be designed to accommodate substantial fire resistance and unlike steel remains structurally stable when subjected to high temperatures. CLT panels can be produced with fire resistances of 30, 60 and 90 minutes.

It’s easy to see why any form of timber construction can pick-up a reputation for fire risk, but for solid wood and Cross Laminated Timber, performance in a fire is a long way from their timber frame cousins.

To understand how efficient CLT is in a fire, we should start with the understanding that fire resistance is the ability of a material to confine a fire or to continue to provide a structural function or both.

The measure of fire resistance is the time elapsed from the start of the fire up until the point where the material fails to function. Typically resistance is expressed in minutes eg FR 30, 45, 60 or 120.

CLT’s fire resistance is provided through ‘charring’.  As the face of the timber panel is exposed to a fire that ramps up to a temperature in excess of 400 degrees C, the surface of the timber ignites and burns at a steady rate. As the timber burns it loses its strength and becomes a black layer of ‘char’. The char becomes an insulating layer preventing an excessive rise in temperature within the unburnt core of the panel. It is this unaffected core which continues to function for the period of the fire resistance.

To achieve the designed fire resistance period there must be sufficient virgin solid timber remaining behind the char layer to sustain the loads applied.  Therefore each CLT panel within the building must be designed for the fire resistance period and the specific loadings applied to that panel.

Fire resistance testing of CLT panels is to ISO 834 – the same standard used for doorsets which most of us are familiar with.

Illustration showing a typical temperature / time gradient through solid timber under fire conditions

https://www.youtube.com/watch?v=hRIPQ_q2iyY