1. Oak Flooring Technical Specification Engineered European Oak.

Your Engineered European Oak Flooring is milled and manufactured in Central Europe as well as some being manufactured here locally in the UK.  To the highest possible standard and finished by Hand in our workshops in Yorkshire, England by Craftsmen using traditional techniques.
Our engineered flooring is made up of a top layer of European Oak bonded to high-quality Birch plywood to ensure the product is very stable and suitable for underfloor heating systems (assuming standard guidelines are met).
There can be some elements of tension between the two elements of an engineered board which can create some bowing along the length, this is perfectly normal. The product is still suitable for installation if the bowing is within the allowed tolerance detailed within this section as correct fitment will ensure that the boards sit flat when installed

Oak flooring Technical specification.

General details:

• Oak Type = European Oak. Oak Source = Central European
• Plywood Type = WBP Birch Plywood. Plywood Source = Russia with alternative Okoume ply now being introduced and is stronger and more durable than the birch ply.
• Product Moisture Content = Between 8 – 11%
• Length Specification = Minimum 80% between 1.8 – 3.0m, maximum 20% between 0.6– 1.8m (unless otherwise requested/advised)
  Jointing system = Tongue & Grooved all 4 edges
• Edge profile = Bevelled 2 long edges only (unless otherwise requested/advised) Maximum bow along the length allowed = 40mm

Product Specification

Grades Available

Prime, Nature, Rustic A/B (Character)
Other widths are possible as a special order from the mill.

2. Engineered European Oak Flooring- Grading Rules and Guidelines

Grade Rules – All products

Attribute

• Prime
• Nature
• Rustic A/B (Character)
• Knot Content
• Only pin knots up to 5mm in diameter are allowed.
• Limited to 3 knots per board.
• Healthy knots up to 20mm in diameter are allowed.
• Filled cracked knots up to 20mm diameter allowed.
• Filled dead knot holes up to 10mm diameter allowed.
• The total number of knots is limited to 3 per board.
• Healthy knots up to 55mm in diameter are allowed.
• Filled cracked knots up to 55mm diameter allowed.
• Filled dead knot holes up to 20mm diameter allowed, (Replacement knots may be used on larger dead knot holes).
• The total number of knots is unlimited.

Other visual imperfections

• No bark pocket splits or wormholes allowed.
• No bark pockets, split or wormholes allowed
• Limited small bark pockets allowed.
• End splits up to 1mm in width and 100mm in length allowed, limited to 20% of total volume.
• No wormhole allowed.
• Sap Content
• No edge sap allowed limited core sap to 5% of total volume.
• No edge sap allowed core sap to be 5% of the total volume.
• Edge sap is limited to 30% of the width of the board.
• Core sap to 15% of total volume.
  Colour
• The natural variation allowed, no dark heartwood allowed.
• The natural variation allowed, no dark heartwood allowed.
• The natural variation permitted small amounts of dark heartwood allowed.

General Description

• Clear grade with only a rare occurrence of any pin knots at all.
• Very light character grade with some Small knots on approx. 40 – 80% of the boards.
• Standard character grade with a selection of natural knots and defects.

Please note that wood is a natural product up to 5% of the material provided may not adhere to these grade rules. For further clarification on what the grade will look like. Please ask for additional reflective samples.

Grades Explained

International Wood Grading Criteria

Unlike many other wood flooring companies, one of the advantages of dealing with SEL/FE for commercial or domestic oak flooring specifications is that we know where our timber is sourced. We have been working with the same sawmill for the past several years, this means that we are familiar with a particular grading system which wouldn’t be possible if we sourced new wood from all over the world.

However, please be aware that most grading is selected by eye. There is always scope for the occasional board to fall outside these parameters. For all these reasons, SEL/FE cannot accept the rejection of an entire order or floor because of the occasional board. Wood is a natural product, and each piece is as original and unique as our fingerprints. These parameters should be taken simply as an indication, given in good faith and to the best of our current knowledge.

We strongly advise that a floor be fitted only by a competent floor fitter, who will, as a matter of course, remove any defects outside of the standard grading allowance as noted below and in many ways, they tailor the floor to fit with the room dynamics. A continuation of the grading process is also carried out during the fitting process, as knots can be removed and boards moved around to suit the space. The individual floorboards cannot be simply vetted on an individual board-by-board basis they must be viewed as a complete room where the overall characteristics of the oak come fully into their own. We cannot accept the rejection of any floor once it has been laid.

Engineered & Solid

Our engineered stock is mostly sold as rustic A/B Character grade. This means that there will be knots up to a max of 55mm.

Character oak flooring.

Cracks, openings, and knots all become a part of the charm of the floor when fitted correctly. If a cleaner grade is required we recommend that the client order a good deal more than that actual floor space, this way the floor can be graded on-site and knots or shakes can be cut away as the client desires please note that if this level of installation is required it must be discussed before quotation as it is a longer fitting process and will therefore be more expensive in labour terms and will also require a larger quantity of boards being supplied. Alternatively, a natural or prime grade of board could be purchased depending on the client’s vision for the space and flooring.

3. Important Facts to note when buying Hand Finished European Oak Flooring

The traditional techniques used involve Distressing, Fuming, Brushing, Ageing, Scraping, Burning, Staining etc. These techniques are not done using high-volume machine-produced automation from Chinese Factories, our techniques are traditional and done caringly board by board individually by hand. Due to the traditional hand-finished nature of our products, there are a few things needed to be noted:

Distressing the wood

If your wood has been distressed to give the appearance of an ‘old, worn and already lived on’ look, the process we use does distress the whole of the board along with the ‘Tongue’ and the ‘Groove’ part of the board. This means extra time and patience will be needed in the fitting process to achieve a fully ‘tight’ joint between planks.

Distressing the wood will cause some of the top parts of the oak to split and break off. This is a natural part of the manufacturing process and is an aspect of the character of the final flooring finish. This form of processing only lends itself to the 21mm thick board, so is not available on the thinner 13mm and 16mm boards. When fitting a distressed floor, it is down to the skill and expertise of the fitter to utilise these pieces and determine which to use and where and which parts of the plank not to use to achieve a fabulous-looking aged floor.
Please ensure you only use a fully competent fitter experienced in fitting bespoke hand-finished flooring. Distressed flooring may appear damaged when viewing an individual piece is normal and is part of the process of a distressed floor.

If you specify Chevron blocks, the points will be rounded off during the process.

Fuming of the wood

Fuming is done to the wood to gently age the wood and give the wood an aged appearance.  The more we Fume the wood, the older it looks. This is a Completely natural reaction with the Tannins in the wood. Some parts of the oak will react more strongly than others with the fuming process, to which colour variation is to be expected.

It is down to the skill and expertise of an experienced fitter to fit a floor that has been fumed to ensure each piece is chosen and laid sympathetically to create an overall aged look to the floor.

Scorching of the wood

Scorching of the oak surface is another technique we use to create a very aged oak floor. The scorching is done by passing hot flame across the oak face board by board. Please be aware the scorching is done in such a way that once fitted it appears natural. Please also note there will be some inevitable scorching to the tongue of the board.

Back scraping of the Oak.

Back scraping is done by hand using traditional tools by a craftsman board by board. The craftsman will ‘scrape’ and ‘tear’ the face of the oak in a very sympathetic way around the knots or grain orientation change within the oak. The boards are ‘Scraped’ depending upon the grain structure in each plank. Some boards will be more heavily scraped than others but always natural. Grain tears and chatter are to be expected.
Please ensure the fitter is comfortable and competent when fitting a hand-scraped plank.

Soft Grain Brushing

Soft Grain Brushing is done to simulate gentle weathering of the oak surface. Please note that during the brushing process of each batch, each board is brushed through the same process. Different parts of the oak tree are Harder, e.g. the ‘heart wood’ is much Harder, than the outer rings of the tree therefore the effect of brushing will be different on each plank. The knots are much harder than straight grain so the brushing effect will reflect this. This is a completely natural process performed on a natural material hence subtle variation between pieces will occur.
Please ensure the fitter is completely comfortable and competent when fitting a Soft Grain Brushed plank.

Packing our Hand Finished Floors

All our production is done completely by hand, board by board and that also includes the packaging of our planks. Your flooring will arrive at your site in ‘Bundles’ packed together by plastic strapping. Any exposed pieces of the oak face will be 100% plastic shrink-wrapped by hand. Please be aware that packaging of Hand Finished Floors is traditionally to ‘Bundle’ the floor in plastic strapping. This method creates a lot less waste of discarded cardboard and plastic and is better for our environment.

Colour Variation of Wood Flooring

Wood is a natural material and will have many variations from board to board and even within a board, not only in the visual features such as grain, knots and growth rings, but more subtlety in the mineral density and fibre density ratio in the exposed wood surface. This natural variation in the wood responds to the process reactions during the manufacturing process whereby the speed of the reactions (e.g. fuming reactivity) and/or the stain absorption saturation point can give rise to variation in hue and density of the observed colour. The result is a distribution or range of colours and tones around a central median colour.
Subtle variations between individual trees and different parts of the same tree can result in different ranges of colour hue and density, and a difference in the median colour of a board exposed to the same production process.
Any batch of flooring will be constituted from more than one tree. The full run of supplied flooring will not only have a wider distribution of colour hue and density than a limited selection shown on a sample panel, board or swatch but may have multiple distributions of colour hue and density overlaid on a range of median colours.

Indeed, a sample panel, being a sample will not exhibit the extremes or full range of the variation in the colour. Examples of how this might appear could be:

• Placing a board against the sample, the board may appear lighter, darker or have a different hue or density in colour
• Two boards placed side by side could have a different median colour • Within a board, the colour may vary(e.g. near a knot)

This is the natural variation as expected from a natural material. The median colour of the sample will reside within the full-colour range of the production batch. The colour variation due to the production process is minimised by treating each order as a single batch and running all the boards through each process stage contiguously.

4. Installation Requirements

General

For your Engineered Flooring product to perform to standard expectations the following conditions must be in place:
It is recommended that the engineered plank flooring should be installed using direct glueing to the subfloor, however, 21mm thick engineered flooring can be directly nailed to joists if they are at 400mm centres or less. This product can be laid as a floating floor but this can result in some spring within the floor, reduce the efficiency of under-floor heating performance and lead to the requirement of very large expansion gaps if the floor area is larger than 5 metres in width. Therefore, it is expected that this flooring will be glued down when installed on underfloor heating.

Environmental Conditions

All major building work including plastering, decorating and kitchen fitting must be completed before fitting the new flooring.
The bundles of flooring shall be stored in a protected dry place on site where the flooring is to be laid. The bundles should ideally be allowed to acclimatise to the room environment for at least 48 hours before installation.

Each board should be carefully checked before installation, do not install any damaged boards. During installation, the temperature of the subfloor should be at least 15°C, and the ambient temperature of the room should be around 20°C During installation, the relative humidity of the room should be between 45-65%, and the ideal is 55%. The subfloor should be clean, dry, flat and free from any cracks or movement. Irregularities on the subfloor should not exceed 3mm over 1 metre in any direction.

Subfloors should not exceed the following humidity levels:

• Cement=no more than2%
• Wooden=no more than10%

Anhydrite = no more than 0.5% If the moisture reading is high on a cement-based subfloor, then you must apply a liquid DPM. If you are using the floating method, you must install a vapour barrier of at least 0.2mm thickness and tape the joints. For your product to perform adequately for years to come the relative humidity and temperature parameters detailed above must be consistent within the property at all times. On some occasions, properties with poor ventilation or very high levels of heating and insulation can have very low relative humidity levels, particularly during colder months. In this situation, there is a risk of shrinkage and possibly even structural deficiencies within the product, therefore a re-humidifier would be recommended. Feel free to contact your supplier for further information. Installation requirements

If you are laying the planks directly onto load-bearing joists, then you must use both flexible adhesive and porta nails to secure each joist.

If you are laying the planks onto an existing floorboard subfloor, then you must ensure that each of the existing floorboards is independently fixed securely to the joist below with no independent movement. If the floorboards have an uneven surface, then correct levelling needs to be done before installation either by levelling the joists or for minor unevenness using a sheet material could be sufficient. If the engineered flooring is to be laid in the same orientation as the existing floorboards, then sheet material must be fixed down first. Sheet material must be screwed down every 15cm in both directions.

An allowance of approximately 15mm around the perimeter of the room should be provided to accommodate any expansion, including under door frames, central heating pipes and connection with tiles.

Bigger rooms will need bigger expansion gaps, please allow a further 2mm expansion gap for every 1 metre of floor width greater than 5 metres.
For direct glue-down installation flexible flooring adhesive must be used and the manufacturer’s recommendations must be followed, never use a rigid or water-based glue.

A minimum of 30cm distance between one header joint and the other of the next row shall be applied when arranging the installation.

Chevron flooring requires attention to the alignment of the points of the blocks. Any misalignment cannot be subsequently corrected.
Any contractor fitting this engineered flooring should adhere to these guidelines, if there are any queries or concerns relating to these guidelines then please do not hesitate to contact us.

5. Supply and Fit Assumptions/Requirements

Before a full supply and the fit price is confirmed a site survey will need to be carried out by a member of our team. During this process the following elements will be assessed:

• • Site conditions
• Quantity of material required
• Any specific fitting detail needed

Depending on when the site survey takes place the site may change between this time and when the installation takes place, therefore the following assumptions are made unless stipulated otherwise:

The site will adhere to the conditions detailed in the ‘Installation Guidelines’ section of this document, For example:

The sub-floor is sound, level and of the appropriate moisture reading There will be no shirtings fitted prior to the installation of the floor.
The area where the floor is to be installed must be clear from all debris, furniture and any other materials, and will not have other contractors working or needing access to that area at the same time.

If any of these installation conditions are not in place at the time of installation we reserve the right to charge for any additional works required (removal of skirting’s, sub-floor levelling etc). If we feel the site is not in the correct condition to receive the flooring we will remove the product and arrange an alternative date to fit (re-arrangement fees may be charged), please note our next available fitting date may not be in the immediate future.

Prior to installation, it is the customer’s responsibility to check the material is in accordance to their invoice, once the installation is started this is deemed as your acceptance of the product provided.
On completion of installation, all moisture and environmental readings will be taken and you will be required to sign off the install.

Supply Only

In the case where we are not installing the flooring, the responsibility for the correct specification of all aspects of the flooring, including measurements and wastage allowance calculation, the verification of the initial and final conditions will reside with the client detailed on our invoice, it is our strong recommendation that these specifications are checked by the person responsible for fitting the flooring.

Protection & additional coats of finish

As detailed in the ‘Maintenance and Aftercare’ section of this document there are additional services often required / recommended e.g. additional coatings of finish / Corex protection. These are not part of our standard installation fee’s but can be provided (price available on request).

Where we are applying an additional coat, the site must be clear of all obstructions and to avoid contamination, other contractors cannot work in the same area at the same time. Nor can they during the curing and drying of the top coat that has been applied to your beautiful floor.

6. Underfloor Heating Requirements

Before installation, you much check and follow all precautions provided by the underfloor heating supplier.

If the heating system is new, the system must have been switched on and operable at normal capacity for at least 3 weeks prior to installation.The heating system must be switched off at least 48 hours prior to installation.All otherwise detailed environmental conditions must be adhered to.On the day of installation, the subfloor should not exceed a temperature of 18°C

The underfloor heating system can be switched on again 1 week after the installation but it must be turned on initially very low and increasing the temperature by 1°C per day.

It is crucial to ensure the floor temperature does not exceed 27°C, to achieve this the system should have an underfloor sensor and suitable cut off capability.Underfloor heating systems can dry the relative humidity out lower than the required levels detailed previously therefore a re-humidifier may be necessary to ensure a consistent relative humidity all year round.

7. Maintenance and After care for your floor

During the floor fitting process we strongly recommend covering the floor immediately after each 5m2 section is fit using a semi rigid corrugated plastic (Corex) type covering. This must be clean and new and applied to a clean, dust free surface ensuring all edges of the floor are sealed using low tac blue or green masking tape and the Corex applied on top of the low tac masking tape, and finally a high strength cloth tape applied between the masking tape and the Corex.

Once the floor has been fully installed and the protective covering carefully removed it is always recommended that an extra coat of the top coat finish is applied prior to the introduction of any furniture. This will remove and slight scratches created during the installation process and it will seal all of the joints between the boards preventing and potential water ingress. This is particularly imperative if the flooring is fitted into a bathroom, kitchen or high traffic area. Please check with your supplier what the appropriate top coat finish is and follow the application guidelines of this finish.

The wood will continue to maintain the moisture level equilibrium with the environment after fitting. To maintain the on-going good condition of the flooring, the air relative humidity of the room should be between 45% and 65%, ideal is 55%.

The room temperature ideally will be kept at an ambient temperature of around 20°C and should not go above 27°C
Everyday maintenance Use a broom, duster or vacuum to remove any dust Weekly / Fortnightly maintenance
Use warm clean water in a bucket and add a capful of the manufacturers recommended wash additive – use a damp well wrung out mop to clean and freshen your floor. (do not use generic flooring cleaners as these can breakdown the top coat).
Every 6 – 12 months (depending on traffic)

Apply manufacturers recommended polish to areas of high traffic, this product can be sprayed directly onto the floor surface and rubbed in using a lint free cloth.

Alternatively, for very high traffic areas such as shops and restaurants we supply a maintenance product to apply directly to the flooring using a cloth to nourish the surface.

Every 5 – 10 years (depending on traffic)

Eventually the top coat finish will begin to wear and at this point it is recommended to apply another coat of the original top coat finish, please check with your supplier which is the appropriate finish for your floor.