Eurocode 5 Guidance Notes
Below is our general guidance on Eurocode 5 certification and the various service classes.
Prebena, one of our partner companies has produced a handy guide to the EN14592 Eurocode 5 Regulations.
Why is Eurocode 5 certification important?
Eurocode 5 (EN 1995-1-1:2004 Design of timber structures) regulations apply a performance standard to the type of fasteners (screws / nails / bolts) used in load bearing timber structures (e.g. timber framing or roofing), as well as setting minimum requirements for corrosion protection. Fasteners meeting this standard must be CE marked to show they comply with the relevant standard.
From July 2013, any jobsite which does not comply with EC5 regulations will be in breach of European Law.
EC5 Nails fall into 3 service classes which are mainly related to the moisture content in timber, but external factors, such as local atmospheric conditions and timber preservation treatments can affect the required Service Class:
Service Class 1 - indoor environment with low moisture content or no damp / condensation (fastener finish may be bright or galv nails with less than 12micron zinc, or a structural staple with min 12micron zinc)
Service Class 2 - area outside the structure's thermal barrier, but is a protected outdoor environment (e,g. fastener with a minimum 12 micron zinc coated galvanising).
Service Class 3 - Unprotected outdoor environment / exposed directly to atmosphere, high humidity, coastal areas (e.g. fasteners with a 50micron Hot Dip Galv coating or stainless steel)
Nailfast CE marked nails fully comply with EC5 regulations – and each box is clearly marked according to service class required.
Eurocode 5 is one of ten Eurocodes aimed at harmonising the standards for all construction products across Europe, simplifying the choice between competing products and opening up the market, encouraging the spread of knowledge and best practice. It also sets minimum acceptable performance criteria.
The objective of Eurocode 5 is that all construction products will be CE marked to show that they are safe and fit for purpose in terms of:
- Mechanical resistance and stability
- Hygiene, health and the environment
- Energy economy and heat retention
The CE mark will supersede national standards.
Nailfast will have full product test data available, while, depending on space, the packaging will have at least the minimum CE labelling requirements.
This information is given as a general guide, as it is the designer who must select the appropriate fastener for their application, while Nailfast will be able to provide a fastener which meets or exceeds that requirement - i.e. if service class 2 for a specific size is required Nailfast will supply Service Class 2 or Service Class 3.
The service classes are easily stated as depending on where the nail will be situated in the completed structure as follows:
1) Service Class 1
Average moisture content in softwood of 12% or less.
e.g. dry internal area / or area not exposed to increased humidity
— corrosion protection required: nails and screws, none required; staples - minimum 12 micron thick zinc galvanising
2) Service Class 2
Average moisture content in softwood of 20% or less.
e.g. are not directly exposed to moisture, but to higher levels of humidity
— corrosion protection required: nails, screws and staples - minimum 12 micron thick zinc galvanising
3) Service Class 3
Average moisture content in softwood of more than 20%.
e.g. directly exposed to external atmosphere / high humidity
— corrosion protection required: nails and screws - minimum 25microns of zinc; staples - stainless steel.
It should be noted that the Service Classes should also be considered in conjunction with timber type and environmental factors. For example certain types of timber and timber treatments will require the use of stainless steel, while a dry area, which is unheated, or occasionally exposed to higher humidity will need a higher level of galvanising than stated by the usual Service Class. If the environment is in a highly corrosive environment, such as coastal areas exposed to high humidity and salinity, then a higher Service Class / higher grade of galvanising may be required.
In addition to the general notes above;
1) It is the responsibility of the designer to decide the level of moisture content the fastener will be exposed to. For example, a standard 90mm nail used to make the frame of a timber kit, would normally only be service class 1, as it would not be exposed to moisture and is in dry timber, but if the house were to be built in an area prone to flooding, would it be appropriate to increase the corrosion resistance of the 90mm nail to either Service Class 2 or 3? These are decisions for the designer.
2) The regulations for Structural Timber Products came into force from 1st July 2013, but does not apply to fasteners which were already in the EU prior to 1st July - so old stocks of non-CE marked product may continue to be sold by us and our distributors, though we will be stocking the full range of nails in Service Class 2. However it is likely that the timber frame panel manufacturer who will have their panels CE tested / marked will require CE marked products in their CE marked panels or the whole panel is no longer compliant.