BM TRADA provides independent technical advice on the adequacy of proposed timber flooring installation systems.
We provide consultancy on issues of installation and identify and advise on potential problem areas before they become a costly in-service issue.
Timber flooring consultancy
Our range of activities in timber flooring consultancy include:
- Guidance on specification and installation practices including advice on fixing and gluing
- Advice and guidance on the expected levels of in-service movement in relation to expected climatic conditions and seasonal variations
- Guidance on species selection and floor covering construction
- Advice on underfloor heating systems and optimal commissioning regimes
- Slip-resistance testing to evaluate the slip potential to pedestrian traffic of flooring and decking systems.
- Consultancy support in the resolution of legal disputes
We have published a professional guide on the installation of wood flooring.
Wood flooring inspection
BM TRADA can undertake specialist site surveys on domestic and sports hall floors, as well as industrial floors to diagnose in-service problems of movement and performance.
Our team of specialist consultants have expertise in various aspects of floor installation and design, enabling diagnostic work to be undertaken from performance-related, aesthetic or structural perspectives.
Typical site surveys may include:
- On-site hygrometric surveys of ambient conditions and sub-floor moisture
- On-site diagnostic surveys to determine the cause(s) of shrinkage, swelling and other forms of distortion (cupping, ridging, de-lamination etc)
- On-site diagnostic investigations into problems of in-service squeaking
- On-site quality monitoring of the adequacy of flooring installations and their compliance with best practice and standards guidance
- Commentary and advice on issues of visual quality and permissible defect levels in relation to consumer expectation
- Provision of expert witness advice in legal disputes
Your timber FAQs Answered
Wood floors are attractive and durable, and an effective way to add character to your home. Wood's environmental credentials are leading to its increased use in flooring for domestic, commercial and specialist applications such as recreation and laboratory facilities. However, the long-term performance of wood flooring depends on careful selection of the system and materials, as well as installation done in the knowledge of what the floor will have to withstand and what is expected of it.
If you cannot find the answer to your query below, please contact our Timber Technical Helpline (normal UK working hours 9–5, Monday to Friday) on 01494 840 349 for free expert advice. A range of relevant timber flooring publications can also be found in the BM TRADA bookshop.
What moisture content should I specify for timber flooring?
Although BS 8201 provides general guidance on the moisture content that timber flooring will generally settle to in different environments, it is important to note that these values can vary.
When specifying a moisture content for timber flooring, you should give special consideration to the heating/air conditioning regime in the building where the floor is to be installed. For example, a conservatory in a house or a glazed atrium in a commercial building may be subject to significant solar gain.
You will find guidance on specifying and achieving the appropriate moisture content in the BM TRADA publication Wood flooring: A professional's guide to installation.
Which timbers are suitable for timber flooring?
Many timber species, both softwood and hardwood, are suitable for timber flooring. Key considerations are appearance and performance, especially resistance to wear and movement characteristics.
A list of species suitable for flooring, including their movement classification and density, is given in BS 8201. Note that some of these species are not commercially popular or readily available. However, you should find it relatively easy to source alternative timbers that can be used in their place.
You can find guidance on selecting appropriate timber species in the BM TRADA Wood Information Sheet Decorative timber flooring.
How long should a screed be left to dry before laying a timber floor over it?
BS 8201 advises a screed drying time of one day per millimetre for the first 50mm, with a longer period being allowed for thicker screeds. Type of construction, screed mix and weather conditions will also have an impact on drying time.
In all cases, you should monitor at regular intervals the humidity levels in the screed to ensure that it is at an acceptable limit before installing the flooring. Methods for monitoring humidity levels are included in Appendix A of BS 8201.
You will find guidance on assessment and preparation of a sub-floor in the BM TRADA publication Wood flooring: A professionals' guide to installation.
Where should I provide gaps for expansion?
This is an important and often complex consideration, and the correct detailing will depend on the demands of your particular flooring design.
It is critical that you have enough provision for expansion (or shrinkage) across the width of the floor, or there may be an increased risk of the development of defects or failure of the floor in service. You should also allow for peripheral gaps around the perimeter of the floor and at its junction with other abutments, and gaps from the bottom of the skirting and around service pipes.
You will find guidance on the provision of expansion gaps in BS 8201, in the BM TRADA Wood Information Sheet Decorative timber flooring, and in the BM TRADA publication Wood flooring: A professionals' guide to installation.
Should I acclimatise my timber flooring before installation?
It is generally accepted that on-site storage prior to installation of pre-finished, factory-dried flooring should be kept to an absolute minimum and that packs of flooring are kept wrapped within their original wrappers until required.
Where on-site storage or acclimatisation of timber flooring is considered necessary, it is vital that the storage conditions are as close as possible to the expected in-service conditions. This will help the timber to achieve its 'equilibrium moisture content' (EMC) and keep the in-service moisture content of the floor to an acceptable minimum.
Follow the flooring manufacturer's recommendations and moisture content guidance in BS 8201 to ensure that you specify appropriate moisture content for the timber. You should have this checked by the installer immediately prior to laying.Wood and its movement properties as well as flooring types and their reaction to moisture are discussed in detail in the BM TRADA publication Wood flooring: A professionals' guide to installation.
How should I fix down a solid timber floor?
Fixed flooring is where the flooring components are nailed down to the underlying battens or joists, resulting in a 'captive' floor surface, with each individual flooring component fixed firmly to the sub-floor.
Specification of fixing for solid timber flooring and modern multi-layered, engineered boards will depend mainly on the type and frequency of fixing and the nature of the substrate.
Fixing is carried out using nails, screws, staples or adhesives and guidance for using these methods is given in BS 8201.
However, it is recommended that you always seek and follow the flooring manufacturer's guidance and recommendations for fixing and for any proprietary sub-floor systems.
You can find guidance on flooring installation and fixing techniques in the BM TRADA publication Wood flooring: A professionals’ guide to installation.
How can I design to prevent floors squeaking in service?
Floors squeaking in service, particularly when subjected to foot traffic, can be caused by a number of factors – and often more than one.
One of the main causes is physical movement of the floor structure due to moisture-related shrinkage of timber components and resulting friction between these components. Other factors include excessive notching or drilling, insufficient strutting or the suitability of fixings.
Consult the BM TRADA Wood Information Sheet Timber joist and deck floors – avoiding movement for specific guidance intended to minimise problems of movement and noise in timber floors in masonry or timber frame buildings.
Which finish should I specify for my solid wood floor?
Although timber flooring can be left unfinished to wear naturally, sealing keeps your floor clean and minimises damage and wear. However, the process does not end with application of the final seal coat. Maintenance and aftercare considerations similarly influence long-term performance and service life.
Your choice of finish will depend upon several factors, such as the desired appearance, slip resistance and wear resistance.
A large number of floor sealing options are available – ranging from oil and wax finishes that require frequent maintenance but are simple to reapply, to polyurethane lacquers that generally provide more resistance to wear, but damage is difficult to repair.
Our experts provide a range of courses from visual strength grading through to designing with Eurocode 5.
BM TRADA provides a range of training courses. Our training portfolio includes timber, fire, management systems, chain of custody, sustainable supply chain and business training.
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