ROOM CONDITIONS
The area to be fitted must be normally heated during the installation – minimum 18°C (81°F), with relative humidity between 35% and 60%.
SUB-FLOOR
Moisture Content - the allowable maximum moisture content on a dry weight basis is 2% for a concrete floor and 0.5% for an anhydrous screed floor. There is no set rule for the drying time of a screed given the variable of the screed and the site conditions. Moisture tests therefore must be carried out using the correct equipment and the results logged and the readings independently verified for the record. Floors that are over the required moisture content levels must be investigated and the issue addressed prior to installation.
Smoothness - the floor surface that the Berg & Berg is to be fitted on to must be permanently dry, level, firm and structurally sound. Variations in levels of the sub-floor of more than 2mm in 1m need to be smoothed.
Prior to fitting, the Berg & Berg must be acclimatised by leave the unopened packs for up to 48 hours in the area to be fitted in order to achieve equilibrium with the environment in to which it is to be fitted. The Berg & Berg is only to be taken out of the packaging just prior to fitting.
WOOD INSPECTION
Being a natural product, within the Berg & Berg grading system which is stringent, there will be variation in colour and knotting within each plank. It is recommended that the boards are sorted to allow a mixture of such variation as opposed to having cleaner and lighter shades in one area and darker and more knotty in another. Some pieces may be best used in less obvious places whereas other boards, with for instance beautiful feature knots, may want to be shown off in key locations.
FLOATING (LAYING THE BERG & BERG ON TO AN UNDERLAY WITH NO FIXING)
A polythene membrane moisture barrier of 0.2mm must be laid directly on the sub-floor with a minimum 200mm overlap which is sealed using vapour tape. The barrier must go up the walls to a minimum of 50mm. The noise reduction underlay, which should be no thicker than 3mm is installed on top.
Berg & Berg has a patented locking system called Svedloc. For additional strength gluing the grooves with PVA glue conforming to the requirement of EN 204 (D3) is recommended. The glue is applied as a continuous bead into the upper part of the groove.
GLUE-DOWN (FULL PASTE OUT WITH ADHESIVE OVER THE FLOOR TO BE FITTED)
The adhesive used must be elastic, water based and solvent free. The instructions supplied by the manufacturer must be followed including the use of primers as directed.
Berg & Berg has a patented locking system called Svedloc. For additional strength gluing the grooves with PVA glue conforming to the requirement of EN 204 (D3) is recommended. The glue is applied as a continuous bead into the upper part of the groove.
SPACING
An expansion gap of between 10 – 15mm must be left between the Berg & Berg and walls and all other hard points such as door frames, stairs and heating pipes. Spacers along the walls help maintain the required spacing during installation of the Berg & Berg. Expansion joints must be installed in all door-ways and if the floor segments are longer than 15m in a lengthways direction or 9m in a width ways direction. Wherever possible the flooring should be laid under door frames.
TOOLS REQUIRED
Tools required for installation include an 800g hammer, a pencil, a tape measure, a hardwood tapping block of around 400 x 65 x 25mm, a parquet bar and distance spacers.
WHERE TO START
Start by laying the wood in the top left hand corner of the room with the groove against the left hand wall. Work your way across to the right of the room linking board by board. The last board is precisely trimmed or shaped to the right hand wall before fitting using the parquet bar. The straight alignment of the first row is extremely important. For greater strength and a more natural look, the end joints should be staggered by a minimum of 600mm. Always use the tapping block and do so against the tongue to prevent bruising the wood.
Should you need to remove a board this can be done as long as any glue adhered has not gone off. Do so by standing on the adjacent installed line and by gently lifting the board from the right hand long edge.
Immediately after completion, or before a long interruption, remove the spacers. Remove any debris from the expansion gaps before covering them with beading, flat-strip, scotia or skirting. Make sure that these are fitted in such a way so as not to trap the Berg & Berg so that it is allowed to move underneath them.
There may be occasional knots where a client or fitter may prefer to add some additional filler or melted hard wax inserting, this can be done easily by a wood fitter. This is not a fault in the wood but is an expected occurrence of a natural product.
Maintenance oil can be used or, for greater resilience and reduced maintenance, a hard wax oil can be used. Any finish applied must be checked for suitability with the supplier and tested in a small and less obvious area of the floor if there are no off-cut pieces available.
Water under-floor heating is suitable for use under Berg & Berg flooring as long as the output is no more than 55 W/m². This must be evenly distributed over the entire surface of the floor. Surface temperatures must not exceed 27°C (81°F) in all places. Even if exterior windows and doors are left open and a cold through draft is created thus reducing the temperature in the room, the under-floor heating must not be able to supply the floor with heat higher than 27°C (81°F). At the start of each heating season the temperature should only be gradually increased evenly over 7 days until normal heating levels are achieved.
With under-floor heating some species have a greater tendency to create small splits and openings between the boards than others, e.g. Beech and Canadian Maple. Within the Berg & Berg range there are species with comparable colour and appearance with better performance.
Due to the variation in types and out-put of different under-floor heating systems, Berg & Berg cannot be guaranteed when electric under-floor heating is in place. The dangers of excessive heat and hot-spots can create issues with wooden flooring. If electric under-floor heating is to be used and Berg & Berg is the chosen product, it is up to the client to seek guarantees from the suppliers / installers of the under-floor heating system. Please be aware of under-floor heating guarantees that guarantee the replacement of underfloor heating systems should they fail, but this can often exclude the screed, floor covering and installation cost.
It is recommended when gluing Berg & Berg down on a floor with water based under-floor heating that the joints are also glued. Berg & Berg has a patented locking system called Svedlock. For additional strength gluing the grooves with PVA glue conforming to the requirement of EN 204 (D3) is recommended. The glue is applied as a continuous bead into the upper part of the groove.
Place suitable high quality entrance matting at every exterior entrance. These must be regularly vacuumed and washed.
Loose dirt, dust and grit should be removed by sweeping or vacuuming.
Fit pads to the bottom of all pieces of furniture that are regularly moved on the Berg & Berg, such as chairs and tables. These pads can also help to reduce the chance of pressure marks over time from particularly heavy pieces of furniture. Furniture with sharp feet or wheels should be placed within cups, again with soft pads on the base, if they are to move. For office chairs the use of appropriate protection mats are recommended.
Always remove moisture spillages immediately with a lightly damp cloth.
Care for a lacquered floor – for cleaning and maintenance of Berg & Berg finished with lacquer, specific Bona floor care products are recommended.
Care for an oiled floor – for cleaning and maintenance of Berg & Berg finished with oil, soap and maintenance oils or Treatex cleaning solutions and hard wax oil are recommended.
Ambient conditions - the area fitted must be maintained at a relative humidity between 35% and 60% to reduce the possibility of deformation and the appearance of small openings in the floor. High temperatures from open fireplaces, tiled stoves or intensive sunlight such as south facing conservatories may cause damage. Air humidifiers during winter months are recommended.
Coverage of the floor with thick rugs or other items where under-floor heating systems are in operation may lead to unacceptable heat concentration.
Fletcher Flooring Ltd t/a Berg & Berg.co.uk. Registered in England Number: 4642871. VAT Number: 808 314149.
Berg & Berg.co.uk 2012